JP3522334B2 - Sine wave oscillation circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sine wave oscillating circuit for obtaining a sine wave signal having a predetermined frequency by utilizing LC resonance.

[0002]

2. Description of the Related Art Conventionally, a sine wave has been used in various fields such as communication, and various oscillation circuits for obtaining this sine wave are known. For example, as typical circuits capable of obtaining a high-frequency sine wave, various Colpitts-type or Hartley-type LC oscillation circuits are known.

Each of these various LC oscillating circuits is, in principle, constructed by combining an amplifier such as a transistor and an LC circuit, and it is necessary to determine each element constant in order to obtain a sine wave of a desired oscillating frequency. There is.

[0004]

By the way, in the conventional sine wave oscillation circuit, the inductor and the capacitor constituting the LC circuit are individually prepared and combined, so that the degree of freedom in design is increased, but the designer or the like is Many element constants are determined, which complicates the design. In particular, depending on the device using the sine wave, it is convenient if the desired oscillation frequency can be easily achieved by combining fewer types of components.

Further, many of the inductors forming the LC circuit have windings on the core or bobbin, and are generally unsuitable for integration. Even if the whole sine wave oscillation circuit including the LC circuit is to be integrated into an IC, there is a disadvantage that only the inductor has to be externally attached, and the whole circuit cannot be integrally formed on the semiconductor substrate. There was a problem.

Further, the above-mentioned conventional sine wave oscillator circuit generates a sine wave having a fixed fundamental frequency.
By replacing the resistors and capacitors with variable elements, the frequency can be varied within a narrow range near the fundamental frequency. Therefore, in order to generate two kinds of sine waves having different frequencies, for example, different frequencies by about 3 to 5 times, basically, two kinds of sine wave oscillation circuits are prepared and the sine wave to be used is used. When it is desired to switch, the prepared sine wave oscillation circuit itself is used by switching. Therefore, there is a problem in that the scale of the oscillation circuit becomes large if two types of sine waves having widely different frequencies are to be generated.

The present invention has been made in view of the above points, and an object thereof is to provide a sine wave oscillating circuit capable of easily generating a sine wave by combining fewer types of components. It is in.

Another object of the present invention is to provide a sine wave oscillation circuit which can be integrally molded on a semiconductor substrate including an LC circuit.

Still another object of the present invention is to provide a sine wave oscillating circuit capable of generating two types of sine waves having greatly different frequencies with a simple structure.

[0010]

Means for Solving the Problems (1) In order to solve the problems described above, a sine wave oscillation circuit of the present invention includes an inverting amplifier that amplifies an input signal and performs phase inversion, and is substantially parallel to a semiconductor substrate. The two inductor conductors formed by the two inductor conductors, and the two inductors formed by the two inductor conductors and the capacitors between them are formed in a distributed constant manner. One of the inductors used as the signal input / output path is connected to each other in series, and a plurality of LC elements in which the other inductors are connected to each other are provided, The output of the inverting amplifier is fed back to the input side via the plurality of inductors connected in series to perform sine wave oscillation.

[0011] (2) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to the invention of (1), the other inductors of the plurality of LC elements are connected to each other via a frequency adjustment capacitor.

[0012] (3) sinusoidal oscillator of the invention, the
In the sine wave oscillation circuit according to the invention of (1), the other inductors of the plurality of LC elements are connected to each other via a varicap.

[0013] (4) a sine-wave oscillator of the invention, the
In the sine wave oscillation circuit according to any one of the inventions (1) to (3) , the inverting amplifier is constituted by an inverter logic circuit.

[0014] (5) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillating circuit according to any one of the inventions (1) to (3) , the inverting amplifier is composed of a grounded source circuit or a grounded emitter circuit.

[0015] (6) a sine-wave oscillator of the invention, the
In the sine wave oscillating circuit according to any one of the inventions (1) to (5) , the LC elements are arranged concentrically and adjacently in the same plane, and function as the two inductor conductors. Two spiral electrodes and a p region formed in a position near the surface of the semiconductor substrate and along the two electrodes, and a p region is formed on one of the two electrodes.
On the other hand, the n region is electrically connected, and a spiral pn junction layer that operates as the capacitor by applying a reverse bias voltage is provided.

[0016] (7) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC elements are arranged substantially opposite to each other with the semiconductor substrate interposed therebetween, and the spirals functioning as the two inductor conductors. The two electrodes having a shape are formed in a position sandwiched between the two electrodes in the semiconductor substrate, and one of these two electrodes is electrically connected to the p region and the other is electrically connected to the n region. And a spiral pn junction layer that operates as the capacitor by applying a reverse bias voltage.

[0017] (8) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC elements are arranged adjacent to each other substantially in parallel on the same plane, and meanders functioning as the two inductor conductors. The two shaped electrodes are formed in a position near the surface of the semiconductor substrate and along the two electrodes, and one of these two electrodes is electrically connected to the p region and the other is electrically connected to the n region. And a meandering pn junction layer that operates as the capacitor when a reverse bias voltage is applied.

[0018] (9) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC elements are arranged to face each other with the semiconductor substrate interposed therebetween, and have a meandering shape that functions as the two inductor conductors. Of the two electrodes and the semiconductor substrate in a position sandwiched between the two electrodes, and one of these two electrodes is electrically connected to the p region and the other is electrically connected to the n region. And a spiral pn junction layer that operates as the capacitor by applying a reverse bias voltage.

[0019] (10) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to any one of the inventions (6) to (9), one of the two electrodes is formed to be shorter than the other.

[0020] (11) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillating circuit according to any one of the inventions (6) to (10), one of the two electrodes functioning as the other inductor is divided into a plurality of pieces, or the two electrodes functioning as the other inductor are divided. It is characterized in that the pn junction layer corresponding to one of the electrodes is divided into a plurality of pieces, and each divided piece is connected between the plurality of LC elements.

[0021] (12) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (6) to (11), by changing the reverse bias voltage applied to the pn junction layer, a capacitor formed in a distributed constant manner in the LC element is provided. It is characterized by changing the capacitance value.

[0022] (13) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC element includes a spiral electrode forming a gate in a MOS structure, and a space between the spiral electrode and the semiconductor substrate. And an insulating layer formed in the semiconductor substrate, and first and second diffusion regions in the semiconductor substrate, which are formed near both ends of a channel formed corresponding to the spiral-shaped electrode and function as a source and a drain. And each of the spiral-shaped electrode and a channel formed corresponding thereto functions as the two inductor conductors, and the channel is used as the signal input / output path. .

[0023] (14) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC element includes a spiral electrode forming a gate in a MOS structure, and a space between the spiral electrode and the semiconductor substrate. An insulating layer formed in the semiconductor substrate, and a first diffusion region in the semiconductor substrate, which is formed near one end of a channel formed corresponding to the spiral electrode and functions as a source or a drain. And each of the spiral-shaped electrode and the channel formed corresponding thereto functions as the two inductor conductors, and the spiral-shaped electrode is used as the signal input / output path. To do.

[0024] (15) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a meandering electrode forming a gate in a MOS structure, and a meandering electrode between the semiconductor substrate and the meandering electrode. And an insulating layer formed in the semiconductor substrate, and first and second diffusion regions formed in the semiconductor substrate near both ends of a channel formed corresponding to the meandering electrode and functioning as a source and a drain. And each of the meandering electrode and a channel formed corresponding thereto function as the two inductor conductors, and the channel is used as the signal input / output path. And

[0025] (16) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a meandering electrode forming a gate in a MOS structure, and a meandering electrode between the semiconductor substrate and the meandering electrode. An insulating layer formed in the semiconductor substrate, and a first diffusion region in the semiconductor substrate, which is formed near one end of a channel formed corresponding to the serpentine electrode and functions as a source or a drain. And that each of the meandering electrode and the channel formed corresponding thereto functions as the two inductor conductors, and that the meandering electrode is used as the signal input / output path. Characterize.

[0026] (17) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a spiral first electrode forming a gate in a MOS structure, and the spiral first electrode. An insulating layer formed between the semiconductor substrate and a second spiral electrode formed on the surface of the semiconductor substrate and concentrically adjacent to the first electrode; And the first of the spiral shape
A first and a second diffusion region formed near both ends of a channel formed corresponding to the electrode and functioning as a source and a drain, and formed corresponding to the spiral-shaped first electrode. The channel and the second electrode each function as the two inductor conductors, and the channel is used as the signal input / output path.

[0027] (18) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a spiral first electrode forming a gate in a MOS structure, and the spiral first electrode. An insulating layer formed between the semiconductor substrate and a second spiral electrode formed on the surface of the semiconductor substrate and concentrically adjacent to the first electrode; And the first of the spiral shape
A first diffusion region formed near one end of the channel formed corresponding to the electrode and functioning as a source or a drain, and the channel formed corresponding to the spiral-shaped first electrode. And that each of the second electrodes functions as the two inductor conductors,
It is characterized in that the second electrode is used as the signal input / output path.

[0028] (19) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a meandering first electrode that forms a gate in a MOS structure, and a meandering first electrode. An insulating layer formed between the semiconductor substrate and a meandering second electrode formed on the surface of the semiconductor substrate so as to be adjacent to and substantially parallel to the first electrode; The first meandering shape is in the substrate.
A first and a second diffusion region formed near both ends of the channel formed corresponding to the electrode and functioning as a source and a drain, and formed corresponding to the meander-shaped first electrode. The channel and the second electrode each function as the two inductor conductors, and the channel is used as the signal input / output path.

[0029] (20) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a meandering first electrode that forms a gate in a MOS structure, and a meandering first electrode. An insulating layer formed between the semiconductor substrate and a meandering second electrode formed on the surface of the semiconductor substrate so as to be adjacent to and substantially parallel to the first electrode; The first meandering shape is in the substrate.
A first diffusion region formed near one end of the channel formed corresponding to the electrode and functioning as a source or a drain, and the channel formed corresponding to the meander-shaped first electrode. And each of the second electrodes function as the two inductor conductors, and the second electrode is used as the signal input / output path.

The sine wave oscillation circuit of (21) is the same as that of (1) above.
In the sinusoidal oscillator circuit according to any one of the inventions to (21), the LC element is formed on one surface side of the semiconductor substrate, and has a spiral first electrode that forms a gate in a MOS structure; An insulating layer formed between the spiral-shaped first electrode and the semiconductor substrate, and a spiral formed on the other surface side of the semiconductor substrate at a position substantially facing the first electrode. A second electrode having a shape, and first and second electrodes formed in the semiconductor substrate near both ends of a channel formed corresponding to the first electrode having a spiral shape and functioning as a source and a drain. And a channel formed corresponding to the spiral-shaped first electrode and the second electrode each function as the two inductor conductors.
The channel is used as the signal input / output path.

[0031] (22) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC element is formed on one surface side of the semiconductor substrate, and has a first spiral shape that forms a gate in a MOS structure. An electrode, an insulating layer formed between the spiral-shaped first electrode and the semiconductor substrate, and formed on the other surface side of the semiconductor substrate at a position substantially facing the first electrode. The spiral-shaped second electrode and the spiral-shaped first electrode in the semiconductor substrate.
A first diffusion region formed near one end of the channel formed corresponding to the electrode and functioning as a source or a drain, and the channel formed corresponding to the spiral-shaped first electrode. And each of the second electrodes function as the two inductor conductors,
It is characterized in that the second electrode is used as the signal input / output path.

[0032] (23) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC element is formed on one surface side of the semiconductor substrate and forms a meandering first gate in a MOS structure. An electrode, an insulating layer formed between the meandering first electrode and the semiconductor substrate, and formed on the other surface side of the semiconductor substrate, at a position substantially facing the first electrode. And a first electrode formed in the vicinity of both ends of a channel formed in the semiconductor substrate corresponding to the first electrode having a meandering shape and functioning as a source and a drain. And a second diffusion region, each of the channel formed corresponding to the meandering first electrode and the second electrode functions as the two inductor conductors, and the channel is Signal input / output It characterized by using as a road.

[0033] (24) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC element is formed on one surface side of the semiconductor substrate and forms a meandering first gate in a MOS structure. An electrode, an insulating layer formed between the meandering first electrode and the semiconductor substrate, and formed on the other surface side of the semiconductor substrate, at a position substantially facing the first electrode. And a second meandering electrode formed in the vicinity of one end of a channel formed in the semiconductor substrate corresponding to the first meandering electrode and functioning as a source or a drain. One diffusion region, and a channel formed corresponding to the first electrode having a meandering shape and the second electrode respectively function as the two inductor conductors, and the second electrode Signal input / output path Characterized in that it and use.

[0034] (25) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (13) to (16), the carrier is preliminarily injected into at least a part of a position near the surface of the semiconductor substrate where the channel is formed, and the spiral shape is formed. Alternatively, the length of the channel is set to be long or short with respect to the meandering electrode, so that the spiral or meandering electrode and the channel are partially opposed to each other.

[0035] (26) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillating circuit according to any one of the inventions (17) to (24), by forming the length of one of the first and second electrodes shorter than that of the other, a spiral shape or a meandering shape is formed. The shaped second electrode and the channel are partially opposed to each other.

[0036] (27) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to any one of the inventions (13) to (24) and (26) , carriers are injected in advance at a position near the surface of the semiconductor substrate where the channel is formed. It is characterized by

[0037] (28) a sine wave oscillating circuit of the present invention, the
(18), (20), (22), (24), (26),
In the sinusoidal oscillator circuit according to any one of (27), when the channel formed corresponding to the first electrode is used as the other inductor,
By dividing the first electrode into a plurality of portions, the channel formed corresponding to the first electrode is divided into a plurality of portions, and the diffusion regions formed near one end of each divided channel are formed into the plurality of diffusion regions. The LC elements are connected to each other.

[0038] (29) a sine wave oscillating circuit of the present invention, the
(17), (19), (21), (23), (26),
In the sine wave oscillation circuit according to any one of (27) , when the second electrode is used as the other inductor, the second electrode is divided into a plurality of pieces and one end of each divided electrode piece is divided. It is characterized in that the neighborhoods are connected between the plurality of LC elements.

[0039] (30) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to any one of the inventions (13) to (29), it is possible to variably control the resistance value of the channel by changing the gate voltage applied to the electrode forming the gate. Characterize.

[0040] (31) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of the inventions (1) to (5) , the LC element has a spiral first shape formed directly on the semiconductor surface or with a first insulating layer sandwiched therebetween.
Electrode, a second insulating layer formed on the surface of the first electrode, and the second electrode at a position substantially opposite to the first electrode.
And a second spiral-shaped electrode formed with the insulating layer sandwiched therebetween, wherein each of the first and second electrodes functions as the two inductor conductors.

[0041] (32) a sine wave oscillating circuit of the present invention, the
In the sinusoidal oscillator circuit according to any one of (1) to (5) , the LC element includes a meandering first electrode formed directly on the semiconductor surface or with a first insulating layer sandwiched therebetween. A second insulating layer formed on the surface of the first electrode, and a meandering second electrode formed so as to sandwich the second insulating layer at a position substantially facing the first electrode. , And each of the first and second electrodes functions as the two inductor conductors.

[0042] (33) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to the invention of (31) or (32) , the second insulating layer is an oxide film formed by oxidizing the first electrode.

[0043] (34) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to the invention of (31) or (32) , the second insulating layer is a semiconductor oxide film or a nitride film formed by a chemical vapor deposition method.

[0044] (35) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to any one of the inventions (31) to (34), one of the first and second electrodes is formed to have a length shorter than that of the other.

[0045] (36) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to any one of (31) to (35), one of the first and second electrodes that functions as the other inductor is divided into a plurality of pieces, and each divided piece is divided into a plurality of pieces. It is characterized in that the LC elements are connected to each other.

[0046] (37) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillation circuit according to any one of the inventions (1) to (36) , the oscillation frequency is switched by changing the operating power supply voltage of the inverting amplifier.

[0047] (38) a sine wave oscillating circuit of the present invention, the
In the sine wave oscillating circuit according to any one of the inventions (1) to (37) , the LC element and the inverting amplifier, or in addition to these, the frequency adjusting capacitor or the varicap is common on the semiconductor substrate It is characterized by being integrally formed.

[0048]

1) The sine wave oscillating circuit according to the invention of (1) described above includes an inverting amplifier and a plurality of LCs formed on a semiconductor substrate.
It is configured by connecting the element with a ring shape. In this inverting amplifier, the phase of the signal is inverted, that is, 1
Since the phase shifts by 80 degrees, the phase is further shifted by 180 degrees by the plurality of LC elements connected to the inverting amplifier, and sine wave oscillation is performed at a frequency such that the phase of the signal after feedback becomes 0 degree or 360 degrees.

As described above , according to the invention of (1) , the sine wave oscillation is performed only by connecting the inverting amplifier and the plurality of LC elements in a ring shape, and it is easy to combine fewer components. A sine wave can be generated.

Further, since the plurality of LC elements described above are formed on the semiconductor substrate, it is possible to form all components including the inverting amplifier on the semiconductor substrate, and mass production using semiconductor manufacturing technology is possible. It is possible to downsize the circuit. In particular, each of these components can be formed on one semiconductor substrate. In this case, the entire circuit is integrally formed on the semiconductor substrate, which facilitates mass production and miniaturization of the circuit.

2) Further, in the sine wave oscillation circuit according to the invention of (2), a capacitor for frequency adjustment is connected in series with each capacitor component of the LC element formed on the semiconductor substrate. It is possible to adjust the phase characteristics and resonance characteristics of the plurality of LC elements according to the capacitance of the frequency adjustment capacitor. Therefore, the frequency of the generated sine wave can be adjusted within a certain range by changing the capacitance of the frequency adjustment capacitor. In particular, since this frequency adjustment capacitor can be formed on the above-mentioned semiconductor substrate at the same time, it can be integrally formed as a whole circuit and can be easily mass-produced and downsized. .

[0052] 3) Further, the sine wave oscillating circuit according to the invention of (3), which has replaced the more frequency adjustment capacitor described above in varicap, by controlling the capacitance of the varicap externally The frequency of the generated sine wave can be changed within a certain range, and the voltage control type sine wave oscillation circuit can be easily configured. Moreover, this varicap can also be integrally formed on the semiconductor substrate together with other components, and it is also the same that mass production and miniaturization of the entire circuit are easy.

4) Further , the invention of (4) or (5) above.
In the sine wave oscillating circuit of the present invention, the above-described inverting amplifier is configured by an inverter logic circuit or a grounded source circuit or a grounded emitter circuit using transistors. That is, each of these is to invert the logic of an input signal and output it, and at the same time, to amplify the voltage level of the input signal. Such a structure can be easily combined with a simple inverting amplifier and an LC element. Can generate waves. In particular, the above-described inverter logic circuit, source grounded circuit, or grounded emitter circuit is generally formed on a semiconductor substrate, which is more convenient when integrally formed with other components.

5) The sine wave oscillation circuit according to the inventions of (6) to (9) is the LC used in the inventions of (1) to (5).
1 shows a first example showing a specific configuration of an element.

According to the invention of (6) , two electrodes concentrically adjacent to each other on the semiconductor substrate, and a spiral pn junction layer formed along these two electrodes are provided. The above-mentioned LC element is formed by. By applying a reverse bias voltage to this pn junction layer, a spiral capacitor is formed. Therefore, the inductor formed by each of the two electrodes and this capacitor are formed on the semiconductor substrate in a distributed constant manner. In particular, since this LC element is formed on a semiconductor substrate using a semiconductor manufacturing technique, it is convenient when integrally formed on a semiconductor substrate together with other components such as an inverting amplifier.

According to the invention of (7) above,
In the invention of (6), the LC element is formed by arranging two electrodes concentrically provided on the semiconductor substrate so as to face each other with the semiconductor substrate sandwiched therebetween, whereby an inductor by each electrode and a pn between them are formed. The capacitor formed of the junction layer is formed in a distributed constant manner. Similar to the LC element of claim 6, since this LC element is formed on the semiconductor substrate by using the semiconductor manufacturing technique, it is convenient when integrally formed with other components such as an inverting amplifier.

According to the inventions of (8) and (9) , the LC element is formed by replacing the spiral shape with the meandering shape of the electrodes in the inventions of (6) and (7) . Generally, it is possible to function as an inductor by forming the conductor into a spiral shape.
Depending on the frequency band used, even if the conductor has a meandering shape, it can function as an inductor. That is, when the electrodes are formed in a meandering shape, each of the concavo-convex portions becomes a coil of about ½ turn and these are connected in series, so that the entire electrode functions as an inductor having a predetermined inductance. Function. In particular, when the frequency of the signal to be used reaches a high frequency region, a small inductance is sufficient, and thus a serpentine inductor may be sufficient.

In particular, when the electrodes are formed in a meandering shape, there is an advantage in that when the wiring is provided at one end or both ends of the electrodes, the wiring can be drawn out without intersecting a part of the electrodes. It is possible to simplify the entire manufacturing process.

6) Further, according to the invention of (10) above ,
By making one of the two electrodes short,
An LC element is formed in which the inductor conductors are partially opposed to each other. Generally, the oscillation frequency of the entire sine wave oscillation circuit is
Since it is determined by the inductance and capacitance formed in a distributed constant, if one electrode is made short to reduce the capacitance, the oscillation frequency will be changed accordingly. Therefore, the oscillation frequency can be adjusted within a certain range by changing the ratio of the electrodes which are partially opposed to each other, and the degree of freedom in designing the sine wave oscillation circuit is increased.

7) Further , according to the invention of (11) above ,
By dividing either one of the two electrodes into a plurality or by dividing the corresponding pn junction layer together with the division of the electrodes, an LC element less affected by the divided inductor conductor is formed. That is, since the self-inductance of each divided electrode piece becomes small, the characteristics of the LC element are substantially determined by the inductance of the undivided electrode and the capacitance formed in a distributed constant. Therefore, the oscillation frequency can be adjusted within a certain range by changing the divided state of the electrodes, and the degree of freedom in designing the sine wave oscillation circuit is increased.

8) Further , according to the invention of (12) above ,
By changing the reverse bias voltage applied to the pn junction layer, the LC element in which the capacitance value of the capacitor formed in a distributed constant can be changed is formed. Generally, the pn junction layer acts as a varicap by applying a variable reverse bias voltage. Therefore, the frequency characteristic can be changed within a certain range by variably controlling the reverse bias voltage to be applied and operating the entire pn junction layer having a spiral shape or a meandering shape as a varicap.
It can be used as an element, and a voltage-controlled sine wave oscillation circuit can be easily realized.

9) The sine wave oscillation circuit according to the inventions of (13) to (24) has a specific configuration of the LC element used in the inventions of (1) to (5) . 2 is an example.

According to the inventions (13) to (16) ,
A MOS structure LC element having a gate having a spiral shape or a meandering shape is formed, and a gate electrode and a channel formed corresponding thereto respectively function as inductor conductors, and a distributed constant capacitor is provided between them. Are formed. Each of these LC elements can be manufactured by using an ordinary process for manufacturing a MOS transistor simply by changing the shape of a mask and the like. When integrally formed on a semiconductor substrate together with other components such as an inverting amplifier. Be convenient for. In particular, when the inverting amplifier also has a MOS structure, for example, when it is composed of an inverter logic circuit such as a MOS transistor or CMOS, the entire sine wave oscillation circuit can have a MOS structure.
This simplifies the manufacturing process and enables high-density mounting of each component, which is particularly convenient when incorporated as part of an IC or LCI.

According to the inventions (17) to (24) ,
The LC element of the MOS structure is formed by providing the second electrode so as to be substantially parallel to or substantially opposite to the gate electrode of each LC element of the inventions (13) to (16), and the gate electrode is It is independently used for reverse bias application. Therefore, it is possible to separate the voltage application to the gate electrode from the signal transmission through the channel or the second electrode, which is particularly convenient when different bias voltages are set for each of the plurality of LC elements.

10) According to the invention of (25) , the LC element is formed by partially opposing the gate electrode and the channel of the inventions of (13) to (16) . Generally, a channel is formed on the surface of the semiconductor substrate corresponding to the gate electrode, but by injecting carriers into at least a part of the position where the channel is formed in advance, when a predetermined gate voltage is applied. The channel may be formed only in a part of the region corresponding to the gate electrode.

11) Further , according to the invention of (26) , one of the two electrodes in the inventions of (17) to (24) is shortened so that the channel and the electrode partially face each other. To form an LC element.

As described above, also in the LC element having the MOS structure, the inductor conductors formed by the channels or the electrodes can be partially opposed to each other, and the oscillation frequency can be set to a certain range by changing the ratio of the partial opposition. The degree of freedom in designing the sine wave oscillator circuit can be increased.

12) According to the invention of (27) , the LC element is formed by previously injecting carriers into the position where the above-mentioned channel is formed,
The LC element has a depletion type MOS structure. In particular, since the channel resistance and the current between the source and drain can be changed by adjusting the amount of carriers to be injected in advance, the characteristics of the LC element can be adjusted within a certain range, and the sine wave oscillator circuit can be designed freely. It will also increase the frequency.

13) Further, according to the invention of (28) above, in the case where the above-mentioned second electrode is used as a signal path, an LC element in which the corresponding channel is divided by dividing the gate electrode into a plurality of portions. Is formed, and the characteristics of the LC element are substantially determined by the inductance of the second electrode which is not divided and the capacitance formed in a distributed constant. Therefore, the oscillation frequency can be adjusted within a certain range by changing the division state of the channel, and the degree of freedom in designing the sine wave oscillation circuit is increased.

14) According to the invention of (29) , on the contrary, when the channel is used as a signal path, the LC element in which the second electrode is divided into a plurality of parts is formed, Even when the second electrode side is divided, the oscillation frequency can be adjusted within a certain range by changing the division state, and the degree of freedom in designing the sine wave oscillation circuit increases.

15) According to the invention of (30) , the LC element in which the channel resistance can be changed by changing each gate voltage of the inventions of (13) to (29) is formed. When the channel resistance, which is the resistance of one of the inductor conductors, is variably controlled in this way, the frequency characteristic of the LC element is also changed according to the degree of the variability. The circuit can be easily realized.

16) Further , the above (31) or (32)
According to the invention, the first electrode, the second insulating layer, and the second insulating layer are formed directly or after forming the first insulating layer on the semiconductor substrate.
The LC element is formed by stacking the electrodes of FIG. Moreover, by making these first and second electrodes substantially face each other, a distributed constant capacitor is formed between these two electrodes functioning as inductor conductors. This LC element has the above-mentioned (6) to (3
Although the LC element shown in the invention of 0) uses the inside of the semiconductor substrate, it is different in that the surface of the semiconductor substrate is used. However, using this semiconductor substrate, other components such as an inverting amplifier are used. It can be integrally formed together with it, and is suitable for mass production and miniaturization of sine wave oscillation circuits.

17) Further, the above (33) or (34)
According to the invention , the LC element is formed in which the insulating layer formed between the two electrodes is composed of the oxide of the electrode or the oxide by the chemical vapor deposition method. The step of forming the insulating layer and the step of forming the spiral or meandering electrode in this manner are realized by a general semiconductor manufacturing technique, and the entire sinusoidal oscillator circuit is integrally formed with other components. It will be convenient.

18) According to the invention of (35) , one of the two electrodes in the inventions of (31) to (34) is shortened so that these electrodes partially face each other. The LC element is formed.

As described above, also in the LC element formed by utilizing the surface of the semiconductor substrate, the inductor conductors formed by the two electrodes can be partially opposed to each other, and the ratio of partial opposition is changed. As a result, the oscillation frequency can be adjusted within a certain range, and the degree of freedom in designing the sine wave oscillation circuit is increased.

19) According to the invention of (36) , an LC element in which any one of the two electrodes in the inventions of (31) to (35) is divided into a plurality of parts is formed. By changing the division state, the oscillation frequency can be adjusted within a certain range, and the degree of freedom in designing the sine wave oscillation circuit increases.

20) Further, according to the invention of (37), a sine wave oscillating circuit in which the oscillation frequency is discontinuously switched by changing the operating power supply voltage of the inverting amplifier is formed. That is, L shown in each of the above claims
By changing the diameter of each inductor of the C element for each different circulating portion, a phenomenon that a single LC element has a plurality of resonance points appears. Therefore, when the operating power supply voltage of the inverting amplifier is changed, the operating point of the inverting amplifier transits from one resonance point to another resonance point, causing a phenomenon in which the oscillation frequency is largely switched. In this way, two types of sine waves with widely different frequencies can be generated by a single circuit without combining separate circuits, and the mounting area is small when the entire circuit is manufactured using semiconductor manufacturing technology. It becomes possible to make it.

21) Further , according to the invention of (38) , it is clarified that the entire sine wave oscillation circuit is integrally formed on the semiconductor substrate. That is, as described above, the LC element of each claim is formed by using a semiconductor substrate, and one of them is provided with an inverter logic circuit, an inverting amplifier composed of a source ground circuit and an emitter ground circuit, and other parts. It is easy to realize a sinusoidal oscillator circuit integrally formed on a semiconductor substrate.

[0079]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sine wave oscillator circuit according to an embodiment of the present invention will be specifically described below with reference to the drawings.

[First Embodiment] FIG. 1 is a diagram showing a detailed configuration of a sine wave oscillation circuit 1 of a first embodiment to which the present invention is applied.

As shown in the figure, the sine wave oscillation circuit 1 of the first embodiment has an inverter logic circuit 10 functioning as an inverting amplifier, and an LC element 12 in which an inductor component and a capacitor component are formed in a distributed constant. , 14 and a capacitor 16 functioning as a load. Each of these components is integrally molded on a common semiconductor substrate.

The inverter logic circuit 10 inverts the logic of the input signal, that is, shifts the phase by 180 degrees and outputs it, and also operates as an amplifier. The inverter logic circuit 10 can be realized by using any logic such as a TTL logic. However, the CMOS logic has a high input impedance and is easy to design a circuit. Among them, a high speed is used when a high frequency sine wave is oscillated. Type 74
A CMOS logic such as HC series is suitable.

The capacitor 16 functions as a load. If the internal capacity of the inverter logic circuit 10 can also be used, the capacitor 16 can be omitted.

Each of the LC elements 12 and 14 has an inductor component and a capacitor component formed in a distributed constant on a semiconductor substrate, and signals are input and output through the inductor portion. Hereinafter, specific examples of the LC elements 12 and 14 will be described.

FIG. 2 is a plan view showing a case where an LC element is constructed by forming spiral spiral electrodes on a semiconductor substrate. Further, FIG. 3 is an enlarged cross-sectional view taken along the line AA shown in FIG.

The LC elements 12 and 14 of this embodiment have a spiral n ⁺ region 32 formed in the vicinity of the surface of a p-type silicon substrate (p-Si substrate) 34, which is a semiconductor substrate, and a part thereof. The formed p ⁺ region 30 is included, and the n ⁺ region 32 and the p ⁺ region 30 form the pn junction layer 36. In addition, p-S described above
Compared to the i substrate 34, the n ⁺ region 32 and the p ⁺ region 30
Has a high impurity concentration, and by applying a reverse bias voltage between the p-Si substrate 34 and the n ⁺ region 32, the p-Si substrate 34 serves as a good isolation region. It is supposed to work. In fact, the reverse bias voltage may be reliably applied between the p-Si substrate 34 and the n ⁺ region 32 by setting the p-Si substrate 34 and the later-described capacitor connecting electrode 28 at the same potential.

Further, the LC elements 12 and 14 of this embodiment are
The first spiral electrode 20 having a spiral shape is formed on the surface side of the n ⁺ region 32 described above and at a position along the n ⁺ region 32. Similarly, a surface side of the p ⁺ region 30, the second spiral electrode 22 is formed at a position along the p ⁺ region 30. Two input / output electrodes 24 and 26 are connected to both ends of the first spiral electrode 20. A capacitor connecting electrode 28 is provided on one end (for example, the outer peripheral side) of the second spiral electrode 22. As described above, the attachment of the input / output electrodes 24, 26 or the capacitor connecting electrode 28 to the first and second spiral electrodes 20, 22 damages the thin n ⁺ region 32 or p ⁺ region 30 as shown in FIG. Not done outside the active area.

In the LC elements 12 and 14 of this embodiment having such a structure, each of the spirally shaped first and second spiral electrodes 20 and 22 functions as an inductor conductor. Also, the first and second
When the pn junction layer 36 electrically connected to each of the spiral electrodes 20 and 22 is used in a reverse bias state, it functions as a spiral capacitor. Therefore, the LC element 1 in which the inductor formed by the first and second spiral electrodes 20 and 22 and the capacitor formed by the pn junction layer 36 exist in a distributed constant manner.
2, 14 are formed.

FIG. 4 is a diagram showing an equivalent circuit of the LC elements 12 and 14 of this embodiment. As shown in FIG. 3A, the first spiral electrode 20 functions as an inductor having an inductance L1, and a signal input from one input / output electrode 24 is propagated through this first spiral electrode 20. It is output from the other input / output electrode 26.

LC element 1 having such an equivalent circuit
2 and 14, when the voltage level input to the input / output electrodes is set higher than the voltage level of the capacitor connecting electrode 28, the pn junction layer 36 composed of the n ⁺ region 32 and the p ⁺ region 30 is reversed. Since a bias voltage is applied, this pn junction layer 36 functions as a capacitor having a capacitance C. Further, this capacitor is formed in a distributed constant manner over the entire length of the first spiral electrode 20 and the second spiral electrode 22.

FIG. 4B shows a structure for applying the above-mentioned reverse bias. Specifically, a bias power supply 38 for applying a predetermined reverse bias voltage is connected between the input / output electrode 24 and the capacitor connecting electrode 28.

Further, as shown in FIG. 9C, a spiral bias shape is obtained by connecting a variable bias power source 44 capable of arbitrarily changing the reverse bias voltage level, instead of the bias power source 38. It is also possible to arbitrarily change the capacitance C of the pn junction layer 36 formed in.

In general, the width of the depletion layer formed at the pn junction surface changes depending on the magnitude of the reverse bias voltage applied to the pn junction layer 36, and the value of the capacitance C also changes accordingly. Therefore, by changing the reverse bias voltage applied to the pn junction layer 36 via the two input / output electrodes 24 and 26, the capacitance C formed in a distributed constant is arbitrarily changed, and the LC elements 12 and 14 as a whole are changed. The frequency characteristic can be changed.

FIG. 5 is a diagram showing a specific configuration for actually applying a reverse bias to the LC elements 12 and 14 in the sine wave oscillation circuit 1 shown in FIG. The case where a variable bias power supply 44 that can be changed arbitrarily is connected is shown.

Since two LC elements are used in the sine wave oscillating circuit 1 of the present embodiment, two LC elements 12 are used by using a common variable bias power source 44 as shown in FIG. 5 (A). , 14 can be applied with a variable reverse bias voltage. When the variable bias power source 44 is actually incorporated as a part of a circuit, it can be configured by combining a variable resistor 52 and a sufficiently large resistor 54 as shown in FIG. That is, a predetermined reverse bias voltage is created by the variable resistor 52, and this reverse bias voltage is applied to the capacitor connecting electrodes 28 of the LC elements 12 and 14 via the sufficiently large resistor 54 to generate an AC component of the signal. It is possible to apply a reverse bias voltage that does not affect the operation.

FIG. 6 is a diagram showing a manufacturing process of the LC elements 12 and 14 of this embodiment. The state of each cross-section along the line BB in FIG. 2 is shown.

(1) Growth of Epitaxial Layer: First, after removing the oxide film on the surface of the p-Si substrate 34 (wafer), the n ⁺ type epitaxial layer 35 is grown on the entire surface of the p-Si substrate 34. ((A) of the same figure).

(2) Formation of Isolation Region: Next, diffusion of p-type impurities or ion implantation is performed to make the region other than the n ⁺ region 32 and the p ⁺ region 30 shown in FIG. 2 an isolation region. To do.

Specifically, first, the surface of the epitaxial layer 35 is thermally oxidized to form an oxide film 40. Then, after removing the oxide film 40 at the position where the p region is to be formed by photolithography, the p region is selectively formed by selectively adding p-type impurities by thermal diffusion or ion implantation. The p region thus formed becomes a part of the p-Si substrate 34 to form an isolation region (FIG. 2 (B)).

As a result of forming the isolation region in this way, the spiral-shaped n ⁺ region 32 is formed by the remaining epitaxial layer 35.

(3) Formation of pn junction layer: Next, p is formed on a part of the n ⁺ region 32 formed in a spiral shape.
Type impurity by introducing by thermal diffusion or ion implantation to form a p ⁺ region 30 of the spiral (FIG. (D)).

Specifically, first, p− including the n ⁺ region 32 is formed.
The surface of the Si substrate 34 is thermally oxidized to form an oxide film 42. Then, the p ⁺ region 30 is formed by photolithography.
After removing the oxide film 42 at the position where the p ⁺ region is to be formed, the p ⁺ region 30 is selectively formed by selectively adding p-type impurities by thermal diffusion or ion implantation.

The p ⁺ region 30 is formed by the n ⁺ formed previously.
Since it needs to be formed in the region 32, the p ⁺ region 30 is formed by adding the p-type impurity in an amount equal to or larger than the amount of the n-type impurity already introduced.

In this way, the spiral pn junction layer 36 including the n ⁺ region 32 and the p ⁺ region 30 is formed.

(4) Formation of spiral electrode: Next, an n ⁺ region 32 and p ⁺ region 30 are formed by photolithography after forming an oxide film 43 on the surface by thermal oxidation.
A spiral-shaped hole is formed on each surface of the first and second parts, and then, the first and second spiral electrodes 20 and 22 are formed by vapor-depositing aluminum, for example, on the spiral-shaped part (see FIG. D)). Further, thereafter, each of the two input / output electrodes 24 and 26 and the capacitor connecting electrode 28 is formed by vapor deposition of aluminum.

The process of manufacturing the LC elements 12 and 14 of this embodiment is basically similar to the process of manufacturing a normal bipolar transistor or diode, and the shape of the pn junction layer 36 and the isolation region between them is formed. Etc. are different. Therefore, it can be dealt with by changing the shape of the photomask in the process of manufacturing a general bipolar transistor, which facilitates manufacturing and is suitable for downsizing.

Incidentally, the LC element 12 of the present embodiment described above,
In the manufacturing process of No. 14, the case where the n ⁺ region is first formed on the entire surface by epitaxial growth and then the isolation is performed has been described as an example.
By photolithography after forming the oxide film on the fourth surface performs Apertures corresponding to n ⁺ region 32 of the spiral, the n ⁺ region 32 by introducing n-type impurities by thermal diffusion or ion implantation into the portion After the formation, the p ⁺ region 30 may be directly formed by the same method. Regarding the method of forming the pn junction layer,
A general semiconductor manufacturing technique can be used.

Thus, the LC elements 12 and 1 of this embodiment are
No. 4 functions as a capacitor because the first and second spiral electrodes 20 and 22 each form an inductor, and the spiral pn junction layer 36 formed between these electrodes is used in reverse bias. To do.
Moreover, since the pn junction layer 36 is formed over the entire length of the first and second spiral electrodes 20 and 22,
The inductances L1 and L2 formed in the first and second spiral electrodes 20 and 22 and the capacitance C formed by the pn junction layer 36 exist in a distributed constant manner.

FIG. 7 is a diagram showing general characteristics of the distributed constant type LC elements 12 and 14 having the structures shown in FIGS.

The characteristic shown in the figure is that the strip-shaped conductor having the input / output leads attached to both ends thereof and the strip-shaped conductor having the capacitor connecting leads attached to the one end thereof are disposed on the dielectric sheet. An LC element formed by winding after sandwiching and laminating (for example, Japanese Patent Laid-Open No. 2-2
It was measured using the "3-terminal type noise filter" disclosed in Japanese Patent No. 6114. This LC element is 3
Used as a terminal element, it inputs an AC signal between one input / output lead (corresponding to the input / output electrode 24) and the capacitor connecting lead (corresponding to the capacitor connecting electrode 28) and the other input / output lead. The results of observing the signal appearing between (corresponding to the input / output electrode 26) and the capacitor connecting lead are shown.

FIG. 11A is a diagram showing the attenuation characteristic,
The horizontal axis represents frequency and the vertical axis represents the amount of attenuation of the output signal with respect to the input signal. Near 20MHz and 150M
It can be seen that there is a large attenuation peak near Hz. In this way, the presence of multiple attenuation peaks is due to the fact that the inductor and the capacitor are formed in a distributed constant,
It is considered that this is because the diameter of the wound belt-shaped conductor changes largely continuously (this point is the same for the first and second spiral electrodes 20 and 22 shown in FIG. 2). In particular, it has been confirmed that a plurality of attenuation peaks appear when the number of turns is set to be large so that the diameter near the inner end portion and the diameter near the outer end portion are greatly different.

FIG. 11B is a diagram showing the phase characteristics, where the horizontal axis shows the frequency and the vertical axis shows the phase shift of the output signal with respect to the input signal. Near 20MHz and 150
It can be seen that the phase abruptly changes in the vicinity of MHz (that is, near the attenuation peak), specifically, 90 degrees or more.

LC whose structure is actually shown in FIG. 2 and FIG.
When the elements 12 and 14 are formed, the first and second spiral electrodes 20 and 22 are formed on the p-Si substrate 34 with a small diameter, so that two strip-shaped conductors are used as dielectric sheets. It is conceivable that the entire characteristic shifts to the high frequency side as compared with an LC element formed by stacking and winding with sandwiching between, but in any LC element, an inductor and a capacitor are formed in a distributed constant manner. The points are the same, and there is no change in the tendency of the attenuation characteristic or the phase characteristic itself.

In the sine wave oscillating circuit 1 of this embodiment, the two LC elements 12 and 14 having such phase characteristics and the inverter logic circuit 10 are connected in a ring shape. Therefore, when the amplification degree of the inverter logic circuit 10 is set to a certain value or more, the oscillation is performed at a frequency such that the phase shift of the signal returned in one round becomes 0 degree or 360 degrees. That is, in the inverter logic circuit 10, 18
Two LC elements 1 excluding this are 0 degrees out of phase
It oscillates at a frequency such that the phase shifts 180 degrees due to 2 and 14.

In other words, since the inverter logic circuit 10 shifts the phase by 180 degrees, the LC element 12 or the like shifts the phase by 180 degrees, and the attenuation amount when the loop makes one round is an inverter logic circuit 10 which is an inverting amplifier.
If it can be compensated by the amplification factor of, the oscillation of a certain frequency will be continued.

By the way, as described with reference to FIG. 7B, since the phase of each LC element 12, 14 changes by 90 degrees or more at a certain frequency, these LC elements 12, 1 are not changed.
When 4 are connected in series, the phase can be shifted by 180 degrees in total, and oscillation occurs at the frequency at this time.

Thus, the sine wave oscillation circuit 1 of this embodiment
Basically, a sine wave can be easily generated simply by combining a small number of components such as one inverter logic circuit 10 and two LC elements 12 and 14. Unlike the LC series resonance circuit, the LC parallel resonance circuit, and the like, the LC elements 12 and 14 have inductors and capacitors formed in a distributed constant in one element.
There is no need to separately prepare and connect the inductor and the capacitor when configuring the oscillator circuit.

In particular, the sine wave oscillation circuit 1 of this embodiment is characterized in that the LC elements 12 and 14 having inductor components are formed on the semiconductor substrate (p-Si substrate 34). Moreover, as a matter of course, the inverter logic circuit 10 and the capacitor 16 shown in FIG. 1 can be formed on the same semiconductor substrate, so that the entire sine wave oscillation circuit 1 can be integrally formed on one semiconductor substrate. It enables mass production and miniaturization of the entire circuit. Further, since the circuit can be integrally formed on this semiconductor substrate by simply using the current semiconductor manufacturing technology and only by changing the shape of the photomask, it is possible to greatly increase the mass production and miniaturization. Cost reduction is also possible.

Further, the LC whose structure is shown in FIGS.
The elements 12 and 14 can change the value of the capacitance C formed in a distributed constant only by changing the value of the reverse bias voltage applied to the pn junction layer 36. Generally, the various characteristics shown in FIG.
When the element characteristics of 0 and the capacitor 16 are fixed, the inductances L1 and L2 of the LC elements 12 and 14 are fixed.
Therefore, if the capacitance C of the LC elements 12 and 14 can be changed, the oscillation frequency itself of the sine wave oscillation circuit 1 changes depending on the degree of the change.

As described above, the sine wave oscillation circuit 1 of this embodiment
By changing the reverse bias voltage applied to the pn junction layer 36 of the LC elements 12 and 14, it is possible to easily form a voltage-controlled oscillation circuit. Moreover, even in the case of such a voltage control type oscillation circuit, it is not necessary to add an element for changing the frequency, and the constituent parts of the sine wave oscillation circuit 1 can be minimized.

FIG. 8 is a diagram showing a modification of this embodiment. In the sine wave oscillating circuit 2a shown in FIG. 7A, the above-mentioned sine wave oscillating circuit 1 directly connects the capacitor connecting electrodes 28 of the LC elements 12 and 14 to each other, whereas It is characterized in that it is connected via a capacitor 46 for frequency adjustment.

In the above-mentioned sine wave oscillation circuit 1, L
Since the oscillation frequency is determined by the inductors and capacitors formed in the C elements 12, 14 in a distributed constant manner, the internal capacitance and the resistance of the inverter logic circuit 10, the LC element 1
Considering the case where the reverse bias voltage applied to the pn junction layers 36 of 2 and 14 is fixed, the element constants cannot be changed if the elements other than the load capacitor 16 are used. Therefore, it is difficult to adjust the oscillation frequency, and the sine wave oscillation circuit 2a shown in FIG. 8A improves this point.

Specifically, LC formed in a distributed constant manner
By connecting the capacitor 46 for frequency adjustment between the respective capacitor components in the elements 12 and 14, the LC element 1
The frequency characteristics of 2 and 14 are changed, that is, the phase-frequency relationship shown in FIG. 7 is changed, and the oscillation frequency of the sine wave oscillation circuit 2a as a whole also changes.

In this way, the oscillation frequency of the sine wave oscillation circuit 2a can be adjusted within a certain range by the capacitor 46 inserted between the capacitor connection electrodes 28 of the LC elements 12 and 14, and the sine wave oscillation of the desired oscillation frequency can be achieved. The circuit 2a can be easily designed, and the degree of freedom in design is increased. In other words, several types of LC elements 1 with different characteristics
Capacitor 4 to be connected simply by preparing 2 and 14
By changing the capacitance value of 6, the sine wave oscillation circuit 2a that oscillates in a wide range of frequencies can be realized.

FIG. 8B shows a structure of a sine wave oscillation circuit 2b having a structure in which the capacitor 46 inserted between the capacitor connecting electrodes 28 of the LC elements 12 and 14 in FIG. 8A is replaced with a varicap 48. FIG.

As described above, the oscillation frequency of the sine wave oscillation circuit 1 can be variably controlled by changing the reverse bias voltage applied to each pn junction layer 36 of the LC elements 12 and 14, but it is replaced. The reverse bias voltage applied to the varicap 48 is changed to
The oscillating frequency of the sine wave oscillating circuit 2b may be variably controlled by changing the capacitance value of the sine wave oscillator 8.

Further, also when the capacitors 46 or the varicaps 48 are added to form the sine wave oscillation circuits 2a, 2b, the capacitors 46 or the varicaps 48 described above together with the LC elements 12, 14 and the like are formed on a common semiconductor substrate. Can be integrally formed.

FIG. 9 is a diagram showing another modification of this embodiment. The sine wave oscillation circuit 2c shown in the figure has a configuration in which a variable voltage power supply 50 is added to the sine wave oscillation circuit 1 shown in FIG. The variable voltage power source 50 functions as an operating power source for the inverter logic circuit 10, and the applied voltage value can be arbitrarily changed.

Even if the operating power supply voltage applied to the inverter logic circuit 10 by the variable voltage power supply 50 is changed within a certain range, the oscillation frequency in the sine wave oscillation circuit 2c does not change. This is because the sine wave oscillation circuit c of this embodiment is LC
This is because the resonance of the elements 12 and 14 is used.

However, if the operating power supply voltage applied to the inverter logic circuit 10 is increased beyond a certain range,
A phenomenon occurs in which the oscillation frequency is discontinuously switched to a high frequency side about 4 to 5 times at a certain voltage value. This is because the optimum frequency (optimal operating point) of the inverter logic circuit 10 shifts to the high frequency side by changing the operating power supply voltage, so that the oscillation has occurred until near the resonance point corresponding to the attenuation peak on the low frequency side shown in FIG. This is because what has been oscillated near the resonance point corresponding to the attenuation peak on the high frequency side. Actually, the sine wave oscillation circuit 2c was assembled using the distributed constant type LC element manufactured by winding the strip-shaped conductor with the dielectric sheet sandwiched between them, and the oscillation frequency was measured. A phenomenon in which 7 MHz sine wave oscillation was observed was observed to switch to approximately 30 MHz sine wave oscillation when the operating power supply voltage was increased, and it was confirmed that the above-mentioned frequency switching was possible. There is.

Since the sine wave oscillating circuit 2c of this embodiment has such an oscillation characteristic, it is possible to generate two sine waves having different frequencies with one circuit.
For this reason, in the past, if two sine waves were to be generated, the sine wave oscillating circuits were separately configured and the circuits to be used had to be switched appropriately, which made the entire circuit complicated. However, the circuit configuration is simplified because each component is sufficient with the single sine wave oscillation circuit 2c formed on the common semiconductor substrate.

The operating power supply voltage applied from the variable voltage power supply 50 to the inverter logic circuit 10 does not necessarily have to be continuously changed. That is, since the oscillation frequency changes at a certain voltage value as a boundary, the variable power supply voltage 50 is formed so that the first and second operating voltages (fixed) lower or higher than this boundary voltage value can be applied. A first operating voltage is applied to the inverter logic circuit 10 to generate a low frequency sine wave, and a second operating voltage is applied to the inverter logic circuit 10 to generate a high frequency sine wave. As a matter of course, two power supplies capable of supplying the first and second operating voltages separately may be prepared, and the power supply to be used may be selected as needed. Also, FIG.
The variable voltage power supply 50 may be added to the sine wave oscillation circuits 2a and 2b shown in FIGS.

As described above, the sine wave oscillation circuit 2 of this embodiment
According to c, the frequencies are greatly different due to the simple configuration.
Any kind of sine wave can be generated. In addition, this 2
The frequency of each type of sine wave can be set within a certain range by changing the number of turns of each spiral electrode 20 and 22 of the LC elements 12 and 14 having the structure shown in FIGS. Can be changed to

FIG. 10 is a diagram showing a modification of the LC elements 12 and 14 described above. In the LC elements 12 and 14 whose structures are shown in FIGS. 2 and 3, the first and second spiral electrodes 20 and 22 are formed in parallel over almost the entire length, that is, substantially the same length, In the LC elements 12a and 14a shown in FIG. 10, the second spiral electrode 22 shown in FIGS. 2 and 3 is shortened by a predetermined number of turns (for example, about 1 turn), and the corresponding pn junction layer 36 is also formed. The feature is that it is shortened by a predetermined number of turns.

As shown in FIG. 10, even when the second spiral electrode 22 and the corresponding pn junction layer 36 are partially omitted, the shortened second spiral electrode 2 is formed.
2 and the inductor formed by the first spiral electrode 20 adjacent thereto, and the shortened pn junction layer 36.
Since the capacitor formed by the LC element is formed in a distributed constant manner, basically, the LC element 1 shown in FIGS.
2 and 14 have the same characteristics.

FIG. 11 is a diagram showing an equivalent circuit of the LC element shown in FIG. As shown in FIG. 7A, the inductance L3 is reduced by the number of turns of the second spiral electrode 22, and the capacitance C1 formed in a distributed constant is also reduced accordingly.

Further, FIGS. 9B and 9C show a structure for applying a fixed or variable reverse bias voltage to the shortened pn junction layer 36. FIG. 4 (B),
Similar to (C), a bias power source 38 or a variable bias power source 44 for applying a fixed or variable reverse bias voltage may be connected between the input / output electrode 24 and the capacitor connecting electrode 28.

As described above, when the first and second spiral electrodes 20 and 22 of the LC elements 12a and 14a are partially opposed to each other and the pn junction layer 36 formed between these electrodes is formed to be short. Is the pn junction layer 36
As a result, the capacitance C1 formed in a distributed constant becomes smaller than that in the case of the LC element shown in FIGS. 2 and 3, so that the frequency characteristic also changes. Specifically, it is expected that both the attenuation characteristic and the phase characteristic shown in FIG. 7 shift to the high frequency side. In other words, the lengths of the partially opposed first and second spiral electrodes 20 and 22 are adjusted, and the pn junction layer 36 formed therebetween is adjusted.
By setting the length to a predetermined length, a desired frequency characteristic can be obtained, and the oscillation frequency in the sine wave oscillation circuit 1 or the like of this embodiment can be set arbitrarily. This also increases the degree of freedom in designing the sine wave oscillator circuit.

FIG. 12 is a diagram showing another modification of the LC elements 12 and 14 described above. LC element 12 shown in FIG.
b and 14b divide the second spiral electrode 22 side into a plurality (for example, two divisions), and also form a pn junction layer 36 formed between the first and second spiral electrodes 20 and 22.
Is also characterized in that it is divided into multiple. That is, the LC elements 12b and 14b shown in FIG.
2 is composed of two divided electrode pieces 22-1 and 22-2, and the p ⁺ region 30 in contact with each divided electrode piece 22-1 and 22-2 is also divided. Each of the divided p ⁺ regions 30 and the n ⁺ regions 32 form two sets of pn junction layers 36. Further, one end of each of the two divided electrode pieces 22-1 and 22-2 (outermost peripheral side and innermost peripheral side)
A capacitor connecting electrode 28 is provided in the.

FIG. 13 is a diagram showing an equivalent circuit of the LC element shown in FIG. As shown in FIG. 3A, the entire first spiral electrode 20 functions as an inductor having an inductance L1, and each split electrode piece 2
2-1 and 22-2 are inductances L4 and L, respectively.
5 functions as an inductor. Then, the first spiral electrode 20 and the divided electrode pieces 22-1 and 22-2
The pn junction layer 36 formed between the two functions as a capacitor having the capacitances C2 and C3, and these capacitors are formed in a distributed constant.

Further, FIGS. 13B and 13C show a configuration for applying a fixed or variable reverse bias voltage to the divided pn junction layer 36. Figure 4
Similar to (B) and (C), a bias power supply 38 or a variable bias power supply 44 for applying a fixed or variable reverse bias voltage may be connected between the input / output electrode 24 and the capacitor connecting electrode 28. Good. Further, in the case where such a power source is realized in an actual circuit, the circuit shown in FIG.
A variable resistor 52 (in the case where the bias voltage is fixed, it is replaced by a voltage dividing circuit composed of two resistors) and a sufficiently large resistor 54 may be used.

As described above, when the second spiral electrode 22 of the LC elements 12b and 14b and the pn junction layer 36 corresponding thereto are divided, each of the divided electrode pieces 22-1 and 22-2.
The self-inductances L4 and L5 of 2-2 become small.
Therefore, the influence of these self-inductances on the characteristics of the entire LC element is reduced, and the LC element 1 is formed by the inductance L1 of the first spiral electrode 20 and the capacitors C2 and C3 formed in a distributed constant.
The characteristics of 2 and 14 are almost determined. Therefore, like the LC elements 12a and 14a shown in FIG.
By examining the divided state of the second spiral electrode 22, the shape of the first spiral electrode 20 that determines the characteristics, and the like, it is possible to obtain an LC element having desired frequency characteristics, and the degree of freedom in design is increased. Will increase.

Since each of the LC elements 12b and 14b has the number of capacitor connecting electrodes 28 corresponding to the number of divisions,
Various methods are conceivable as a connection method when configuring the sine wave oscillation circuit 1 and the like in FIG. FIG. 14 is a diagram showing an example of the connection. The same figure (A) shows the case where all the capacitor connecting electrodes 28 are commonly connected, and the same figure (B) shows the case where only the corresponding capacitor connecting electrodes 28 are connected. The same applies when the capacitors 46 and the varicaps 48 are inserted as shown in FIG. In such cases, various insertion modes are possible.

Second Embodiment FIG. 15 is a diagram showing a detailed configuration of the sine wave oscillation circuit 3 of the second embodiment to which the present invention is applied. The sine wave oscillator circuit 3 of the present embodiment is the sine wave oscillator circuit 1 of the first embodiment described above.
2 uses the inverter logic circuit 10 as an inverting amplifier, it is characterized in that it uses a source grounded circuit with MOS transistors as an inverting amplifier.

That is, the sine wave oscillating circuit 3 shown in FIG.
Is the same as the inverter logic circuit 10 shown in FIG.
6 is replaced with the resistor 58 connected to the drain side of the MOS-FET 56 and the resistor 58.
And constitute a source grounded circuit that functions as an inverting amplifier.

The operating principle of the sine wave oscillating circuit 3 is the same as that of the sine wave oscillating circuit 1 of the first embodiment described above.
The C elements 12 and 14 generate a sine wave having a frequency near the resonance point such that the phase is inverted by 180 degrees.

Regarding the LC elements 12 and 14, the first and second spiral electrodes 20 and 22 and the pn junction layer 36 are formed on the p-Si substrate 34 as shown in FIGS.
The sine wave oscillating circuit 1 shown in FIG. 1 is used except that the grounded source circuit composed of the MOS-FET 56 and the resistor 58 is used as an inverting amplifier. There is no change. In addition,
The LC elements 12 and 14 are the LCs shown in FIGS.
It goes without saying that the elements 12a, 14a or 12b, 14b can be replaced.

As described above, the MOS-F is used as the inverting amplifier.
A sine wave can be generated by a simple configuration in which a source grounded circuit including an ET 56 and a resistor 58 is used and two LC elements 12 and 14 are connected in series to this inverting amplifier in a ring shape.

In particular, when the inverting amplifier is composed of the source-grounded circuit, the entire sine wave oscillation circuit 3 of this embodiment can be manufactured by a general semiconductor manufacturing technique, so that it is integrally formed on the semiconductor substrate. This is more convenient when it is carried out, and it is suitable for high-density packaging of circuits, IC, and LSI.

16 and 17 are views showing a modification of this embodiment. The sine wave oscillator circuit 4a shown in FIG.
Is a capacitor connecting electrode 28 of the LC elements 12 and 14.
They are connected to each other through a capacitor 46, and correspond to the sine wave oscillation circuit 2a shown in FIG. 8A of the first embodiment. By arbitrarily setting the capacitance value of the capacitor 46, the frequency of the generated sine wave can be arbitrarily adjusted.

The sine wave oscillator circuit 4b shown in FIG.
Is a capacitor connecting electrode 28 of the LC elements 12 and 14.
They are connected to each other via a varicap 48, and correspond to the sine wave oscillation circuit 4b shown in FIG. 8B of the first embodiment. By variably controlling the reverse bias voltage applied to the varicap 48 from the outside, the capacitance value of the varicap 48 can be arbitrarily changed within a fixed range, and the sine wave oscillation circuit 4b of the voltage control type can be easily provided. Can be configured.

The sine wave oscillator circuit 4c shown in FIG.
The operating power supply voltage of the grounded source circuit composed of the S-FET 56 and the resistor 58 is applied by the variable voltage power supply 50 and corresponds to the sine wave oscillating circuit 2c shown in FIG. 9 of the first embodiment. To do.

By continuously changing the operating power supply voltage applied to the drain side of the MOS-FET 56 through the resistor 58 by the variable voltage power supply 50, or switching the operating power supply voltage stepwise, one common simple circuit is used. It is possible to generate two sinusoidal waves having greatly different frequencies. This is because the source-drain current changes by changing the operating power supply voltage to be applied, and the optimum operating speed also changes with the change of the internal resistance of the MOS-FET 56, so that the oscillation frequency is discontinuously switched. It is a thing.

FIG. 18 is a diagram showing another modification of this embodiment. The sine wave oscillating circuit 4d shown in the figure is characterized in that a bias circuit is added to the sine wave oscillating circuit 3 shown in FIG.

That is, in the sine wave oscillating circuit 3 shown in FIG. 15, the feedback signal via the LC elements 12 and 14 is MOS-.
Since it is directly input to the gate of the FET 56, the capacitor 16 that serves as a load and the resistor 5 that constitutes the source grounded circuit
By properly adjusting the element constants such as 8
It is necessary to set the optimum operating point of the ET56. On the other hand, in the sine wave oscillation circuit 4d shown in FIG. 18, the bias circuit capable of setting an arbitrary gate voltage has resistors 60 and 62.
It is formed by the voltage dividing circuit by
The optimum operating point of T56 can be easily adjusted.

The capacitor 64 is a MOS-FET.
It functions as a DC component separating circuit for removing a DC component from the signal fed back to the gate of 56, and it is preferable to use one having a large capacitance value that does not change the phase of the input signal. .

Although only the configuration corresponding to the sine wave oscillator circuit 3 shown in FIG. 15 has been described, the configuration shown in FIG.
A bias circuit composed of resistors 60 and 62 and a DC component separation circuit composed of a capacitor 64 are added to the sine wave oscillator circuits 4a, 4b and 4c shown in FIGS. Good.

[Third Embodiment] FIG. 19 is a diagram showing a detailed configuration of a sine wave oscillation circuit 5 according to a third embodiment of the present invention. The sine wave oscillator circuit 5 of the present embodiment is the sine wave oscillator circuit 1 of the first embodiment described above.
2 is an inverter logic circuit 10 as an inverting amplifier,
The sine wave oscillating circuits 3 and 4a to 4d of the embodiment use a source grounded circuit using MOS transistors as an inverting amplifier, but are characterized in that a grounded emitter circuit using bipolar transistors is used as an inverting amplifier. .

That is, the sine wave oscillation circuit 5 shown in FIG.
Has a configuration in which the inverter logic circuit 10 shown in FIG. 1 is replaced with a grounded-emitter circuit including a bipolar transistor 66 and a resistor 68, and this grounded-emitter circuit operates as an inverting amplifier.

The capacitor 72 inserted in the feedback loop functions as a DC component separating circuit for removing the DC component. Further, a predetermined bias is applied to the base of the bipolar transistor 66 from the collector via the resistor 70, whereby an appropriate operating point is set.

The operating principle of the sine wave oscillating circuit 5 is the same as that of the sine wave oscillating circuit 1 and the like described above.
2, 14 generate a sine wave having a frequency near the resonance point such that the phase is inverted by 180 degrees.

Regarding the LC elements 12 and 14, as in the first and second embodiments, the first and second spiral electrodes are formed on the p-Si substrate 34 as shown in FIGS. 20 and 22 and a pn junction layer 36, and the circuit connection method is shown in FIG. 1 except that a grounded-emitter circuit composed of a bipolar transistor 66 and a resistor 68 is used as an inverting amplifier. There is no difference from the sine wave oscillator circuit 1 and the like. In addition, LC
It goes without saying that the elements 12 and 14 can be replaced with the LC elements 12a and 14a or 12b and 14b shown in FIGS.

In this way, the bipolar transistor 66
Inverting amplifier (grounded emitter circuit)
The sinusoidal wave can be generated by a simple configuration in which the two LC elements 12 and 14 are connected in a ring shape.

Further, the LC element 1 shown in FIGS. 2 and 3 is used.
Since 2 and 14 have a sectional structure similar to that of a bipolar transistor, the entire sine wave oscillation circuit 5 including these LC elements 12 and 14 and the bipolar transistor 66 is formed using the same semiconductor manufacturing technique. Is possible, which is more convenient for mass production and miniaturization by integral molding.

20 and 21 are views showing a modification of this embodiment. The sine wave oscillation circuit 6a shown in FIG.
Is a capacitor connecting electrode 28 of the LC elements 12 and 14.
They are connected to each other via a capacitor 46, and correspond to the sine wave oscillation circuits 2a and 4a shown in FIG. 8A of the first embodiment or FIG. 16A of the second embodiment. To do. By arbitrarily setting the capacitance value of the capacitor 46, the frequency of the generated sine wave can be arbitrarily adjusted within a certain range.

The sine wave oscillation circuit 6b shown in FIG.
Is a capacitor connecting electrode 28 of the LC elements 12 and 14.
The sine wave oscillation circuits 2b and 4b shown in FIG. 8B of the first embodiment or FIG. 16B of the second embodiment are connected to each other via the varicap 48. Corresponding. By variably controlling the reverse bias voltage applied to the varicap 48 from the outside,
The capacitance of the varicap 48 can be arbitrarily changed within a fixed range, and the voltage control type sine wave oscillation circuit 6b can be easily configured.

The sine wave oscillating circuit 6c shown in FIG. 21 is such that the operating power supply voltage of the inverting amplifier composed of the bipolar transistor 66 and the resistor 68 is applied by the variable voltage power supply 50. 9 or the sine wave oscillator circuits 2c and 4 shown in FIG. 17 of the second embodiment.
It corresponds to c.

By continuously changing or discontinuously changing the operating power supply voltage applied to the collector side of the bipolar transistor 66 through the resistor 68 by the variable voltage power supply 50, one common simple operation can be performed. The circuit can generate two sine waves with different frequencies. This is because the optimum operating speed of the bipolar transistor 66 also changes by changing the operating power supply voltage to be applied, so that the oscillation frequency switches discontinuously, and basically, the MOS-FET 56.
Is the same as in.

It should be noted that the resistor 6 as shown in FIG. 18 is used without using the resistor 70 for bias application connected to the collector.
A voltage divider circuit composed of 0 and 62 may be added to apply a constant bias voltage to the base of the bipolar transistor 66. As described above, by separately providing a voltage dividing circuit for bias application, a constant bias voltage can be always applied regardless of the voltage level appearing at the collector, and a stable operating point of the bipolar transistor 66 can be secured. Will be able to.

Other Examples Next, other examples to which the present invention is applied will be described.
Various embodiments described below are realized by the LC elements 12 and 14 used in the above-described first to third embodiments with other structures.

FIG. 22 is a plan view showing a schematic structure of an LC element in another embodiment. 23 is an enlarged sectional view taken along the line AA shown in FIG.

The LC device 12 of this embodiment shown in these figures.
c (or LC element 14c) is a semiconductor substrate p
-By forming the n region 130 near the surface of the Si substrate 134, a pn composed of the n region 130 and the p region 132 is formed.
The bonding layer 136 is formed.

The LC elements 12c and 14c of this embodiment are also
Is a spiral-shaped first portion on the surface side of the n region 130 described above.
Spiral electrode 120 is formed. Similarly, p
The surface side of the region 132, that is, the first spiral electrode 1
A second spiral electrode 122 is formed on the opposite side of the pn junction layer 136 with respect to 20, and at a position substantially facing the first spiral electrode 120. Two input / output electrodes 24 and 26 are provided on both ends of the first spiral electrode 120. The capacitor connecting electrode 28 is provided at one end (for example, the outer peripheral side) of the second spiral electrode 122.

The LC elements 12c and 14c of this embodiment having such a structure are similar to the LC elements 12 and 14 shown in FIGS. 2 and 3, and the first and second spiral electrodes 120 having a spiral shape. , 122 will function as inductor conductors.

Also, the first and second spiral electrodes 1
When the pn junction layer 136 formed between 20 and 122 is used in a reverse bias state, it operates as a capacitor. Note that, as shown in FIG. 23, the pn junction layer 136 is considered to be one capacitor having a large counter electrode (each of the n region 130 and the p region 132 corresponds to the counter electrode). However, in general, n region 130 and p region 132
Each of the first and second spiral electrodes 120,
Since the specific resistance is larger than that of the first and second spiral electrodes 122, 122, when an AC signal is applied between the first and second spiral electrodes 120 and 122, the first and second spiral electrodes 12 facing each other.
AC signal flows only through the spiral-shaped capacitor between 0 and 122, and the first and first spiral electrodes 12
Almost no AC signal flows through the capacitors formed between the different circulating portions of 0 and 122. Therefore, the pn junction layer 136 other than the surrounding portions of the first and second spiral electrodes 120 and 122 hardly functions as a capacitor, and the first and second spiral electrodes 12
It can be considered that only the spiral-shaped portion along the circumference of 0,122 substantially operates as a capacitor.

Therefore, the inductor formed by the first and second spiral electrodes 120 and 122 and the pn
The LC elements 12c and 14c in which the spiral capacitors formed by the bonding layer 136 exist in a distributed constant form.

The LC element 12c having such a structure,
As the equivalent circuit of 14c, the one shown in FIG. 4 can be applied as it is. Further, by connecting a bias power supply 38 or a variable bias power supply 44 for applying a fixed or variable reverse bias voltage, a fixed or variable predetermined reverse bias voltage can be applied, whereby a predetermined capacitor can be set. Is also the same.

FIG. 24 shows the LC element 12 shown in FIG.
It is a figure which shows the modification of c and 14c, and corresponds to FIG. That is, the LC element 12d shown in FIG.
(14d) is a predetermined number of turns (for example, about 1 turn) in the second spiral electrode 122 of the LC element shown in FIG.
It is characterized in that it is shortened, and with this change, a spiral pn between the first and second spiral electrodes 120 and 122 that functions as a distributed constant capacitor.
The bonding layer 136 is also shortened by a predetermined number of turns.

FIG. 25 shows the LC element 12 shown in FIG.
It is a figure which shows the other modified example of c and 14c, and corresponds to FIG. That is, the second spiral electrode 12
It is characterized in that 2 is divided into a plurality of pieces (for example, two pieces), and the capacitor connecting electrode 28 is connected to one end of each of the divided electrode pieces 122-1 and 122-2. The equivalent circuit shown in FIG. 13 can be applied as it is.

As described above, the second spiral electrode 122
By dividing into plural, the spiral-shaped pn junction layer 136 formed correspondingly is also divided into plural.
Therefore, the self-inductance of each divided electrode piece of the second spiral electrode 122 is reduced, and the LC element 12
e and 14e, the overall characteristics are the inductance L1 of the first spiral electrode 120 and the divided pn junction layer 136.
Will be substantially determined by the respective capacitances C2 and C3 of.

As shown in FIG. 24 or FIG. 25, the first and second spiral electrodes 120 and 122 are partially opposed to each other, or one of the second spiral electrodes 122 is divided into a plurality of parts. The LC elements 12c and 14c shown in FIG. 22 can be LC elements having different frequency characteristics. Therefore, an LC element having a desired frequency characteristic can be obtained by arbitrarily setting the length of the second spiral electrode 122, the place where the second spiral electrode 122 is divided, or the number of divisions, whereby the sine wave oscillation circuit shown in FIG. 1 is obtained. The oscillation frequency such as 1 can be arbitrarily set within a certain range.

In the LC element formed by making the first and second spiral electrodes 120 and 122 substantially face each other, the p-Si substrate 134 is entirely formed of the pn junction layer 136 including the n region 130 and the p region 132. However, as shown in FIG. 26, the n region 130 (or the p region 132 may be used) may have a spiral shape along the first spiral electrode 120. In this case, since a depletion layer is formed at the boundary surface (pn junction surface) between the n region 130 and the p region 132 formed along the spiral shape, a spiral capacitor is formed, and therefore FIG. It is possible to more reliably form the spiral capacitor than the structure shown in FIG.

When the p-Si substrate 134 is actually used as the pn junction layer 136 composed of the n region 130 and the p region 132, the thickness of the p-Si substrate 134 needs to be thinner than that of the wafer. is there. Further, in consideration of the fact that an n-type wafer is generally easier to obtain, the structure shown in FIG. 27 may be adopted.

That is, as shown in FIG.
P is formed on the surface of the Si substrate 144 by epitaxial growth or the like.
After forming the region 132, etching is performed on the back surface side of the n-Si substrate 144, and the first and second spiral electrodes 120 and 122 are formed on the etched portion. Further, as shown in FIG. 3B, the p ⁺ region 146 and the n ⁺ region 1 are sequentially arranged on the surface side of the n-Si substrate 144.
After forming 48, the n-Si substrate 144 is etched, and the first and second spiral electrodes 120 and 122 are formed in the etched portions. In addition, as shown in FIG.
The spiral p ⁺ region 146 is formed substantially along the spiral electrode 120, and then the spiral n ⁺ region 148 is further formed thereon, and then the n-Si substrate 1 is formed.
A portion of the back surface of 44 corresponding to the second spiral electrode 122 is etched, and the etched portion is covered with the first and second spiral electrodes 120, 12.
Form 2.

The LC element of each of the above-mentioned modified examples is the first
Spiral electrode 120 and second spiral electrode 122
Although it is shown that and are completely opposite to each other, the first and second
Since the spiral electrodes 120 and 122 need to function as the electrodes of the capacitor formed by the pn junction layer 136, the spiral electrodes 120 and 122 may be arranged so as to be slightly opposed to each other.

FIG. 28 is a diagram showing another example of the LC element. The LC elements 12f and 14f shown in the figure are characterized in that the shapes of the first and second spiral electrodes 20 and 22 of the LC elements 12 and 14 shown in FIG. 2 are changed. Specifically, in the LC elements 12f and 14f of the present embodiment, first and second electrodes 150 and 152 having a meandering shape instead of the first and second spiral electrodes 20 and 22 having a spiral shape in FIG. And these two electrodes 1
A pn junction layer 154 having a meandering shape is formed along 50 and 152.

FIG. 29 is a diagram showing the principle of an inductor formed by first and second electrodes 150 and 152 having a meandering shape. As shown in the same figure, when a current in one direction is applied to the electrode 150 or 152 having a meandering shape that is bent in a concavo-convex shape, magnetic fluxes whose directions are opposite to each other in adjacent concavo-convex portions are alternately generated. , As if 1 /
The two-turn coils are connected in series. Therefore, each of the first and second electrodes 150 and 152 functions as an inductor having a predetermined inductance, and the equivalent circuit shown in FIG. 4 can be applied as it is.

In the case of a spiral electrode, one of both ends of the electrode is located at the center and the other is located at the periphery, whereas the meandering electrodes 150, 15 are provided.
In the case of No. 2, both ends are located in the peripheral portion, which is convenient when the input / output electrodes 24, 26 and the capacitor connecting electrode 28 are drawn to the outside.

Further, the LC element 1 having such a structure
In 2f and 14f, the second electrode 152 side may be formed short or may be divided into a plurality of parts.

FIG. 30 shows the second electrode 15 shown in FIG.
The LC elements 12g and 14g whose lengths on the second side are approximately halved are shown and correspond to FIG. Further, FIG. 31 shows LC elements 12h and 14h in which the side of the second electrode 152 is divided into a plurality of pieces (for example, two pieces), and corresponds to FIG.

32 to 34 are diagrams showing other examples of the LC element. LC elements 12i and 14i shown in FIG.
Is a first and second electrode 160, 1 having a meandering shape.
62 is formed so as to substantially face each other with the p-Si substrate 134 interposed therebetween, and corresponds to FIG. That is, the LC elements 12c and 14c shown in FIG. 22 are the spiral first and second spiral electrodes 120 and 1c.
22 are opposed to each other, the LC of this embodiment is
The elements 12i and 14i include the first and second electrodes 160 and 1
The feature is that the shape of 62 is a meandering shape. Therefore, the first and second electrodes 160, 1 having a meandering shape
Each of 62 functions as an inductor having a predetermined inductance, and as a capacitor in which a meandering pn junction layer 136 (the cross-sectional structure is the same as that shown in FIG. 23) sandwiched between them is formed as a distributed constant. Will work.

In addition, the LC elements 12j and 1 shown in FIG.
4j reduces the length of the second electrode 162 shown in FIG.
0 and 162 are partially opposed to each other, and correspond to FIG. Furthermore, the LC element 12 shown in FIG.
k and 14k are the second electrodes 162 shown in FIG.
25 is divided into two and the capacitor connecting electrodes 28 are connected to the ends thereof, which corresponds to FIG.

As described above, even when the serpentine first and second electrodes 160 and 162 are opposed to each other with the p-Si substrate 134 having the pn junction layer 136 formed therebetween,
L in which the inductor and the capacitor are formed in a distributed constant
A C element can be formed, and the LC element can be used to configure the sine wave oscillation circuit shown in FIG. 1 or FIG. Moreover, the inverter logic circuit 10 and the like can be formed on the p-Si substrate 134 on which the LC elements 12c and 14c and the like are formed, and mass production and miniaturization by integral molding can be easily realized. it can.

FIG. 35 is a diagram showing another example of the LC element. 36 is an enlarged sectional view taken along the line AA of FIG.
7 is an enlarged sectional view taken along line BB of FIG. 35, and FIG. 38 is C of FIG.
It is a C line expanded sectional view.

The LC device 12 of this embodiment shown in these figures.
m and 14m are formed by applying a voltage to the spiral spiral electrode 210 that functions as a gate between a source 212 and a drain 214, which are diffusion regions formed at spaced positions near the surface of the p-Si substrate 34. The feature is that they are connected by a channel 222.

Source 212 and drain 21 described above
4 is formed by inverting the p-Si substrate 34 as a diffusion region of the n ⁺ layer. For example, it is formed by implanting As ⁺ ions by thermal diffusion or ion implantation to increase the impurity concentration.

The spiral electrode 210 functioning as a gate has a p-Si substrate so that one end of the spiral shape overlaps part of the source 212 and the other end overlaps part of the drain 214. It is formed so as to sandwich the insulating layer 226 formed on the surface of 34. The spiral electrode 210 is formed, for example, by forming a thin film of aluminum, copper, silver or the like, or by heavily doping P by diffusion or ion implantation.

The insulating layer 226 is formed on the p-Si substrate 34.
The surface of the p-Si substrate 34 and the spiral electrode 210 are insulated from each other. The entire surface of the p-Si substrate 34 (or at least the spiral electrode 21
The portion corresponding to 0) is covered with this insulating layer 226, and the spiral electrode 210 described above is formed on the surface of this insulating layer 226. The insulating layer 226 is formed of, for example, P-added SiO ₂ (P-glass).

In addition, the spiral electrode 210, the source 212, and the drain 214 described above are respectively provided in FIGS.
As shown in FIG. 38, the capacitor connecting electrode 28 and the input / output electrodes 24 and 26 are connected. That is, the capacitor connecting electrode 28 with respect to the spiral electrode 210.
Is done outside the active area so as not to scratch the thin gate film (insulating layer 226), as shown in FIG. As shown in FIG. 38 or FIG. 36, the source 21 is attached to the source 212 and the input / output electrode 24 is attached to the drain 214.
2 and a part of the drain 214 are exposed, and then a metal film of aluminum, copper, gold, silver or the like is attached. Further, as shown in FIG. 37, the input / output electrode 26 connected to the drain 214 located in the substantially central portion of the spiral shape is drawn to the outer peripheral side so as to maintain an insulating state with each circumscribed portion of the spiral electrode 210. There is.

L of the present embodiment having the MOS structure described above
Assuming that the C elements 12m and 14m have an n-channel enhancement type structure, the spiral electrode 2
Only when a positive voltage is applied to 10 will the n-type channel 222 be formed. Each of the channel 222 and the spiral electrode 210 described above functions as a spiral inductor conductor, and the channel 222 and the spiral electrode 210 are formed.
A distributed constant capacitor is formed between them.

FIG. 39 is a sectional view showing a state in which the channel 222 is formed, and shows a section taken in a direction perpendicular to the spiral direction of the spiral electrode 210. When a positive gate voltage is not applied to the spiral electrode 210, that is, to the capacitor connecting electrode 28 connected to the spiral electrode 210, as shown in FIG. Does not show channel 222. Therefore, in this state, the source 212 and the drain 214 shown in FIG. 35 are in an insulated state.

However, when a positive gate voltage is applied to the spiral electrode 210, as shown in FIG. 39B, the p-Si substrate 34 corresponding to the spiral electrode 210 is formed.
A channel 222 consisting of an n region appears near the surface of the. Since the channel 222 is formed over the entire length of the spiral electrode 210, the charge accumulated in each of the spiral electrode 210 and the channel 222 forms a distributed constant capacitor between them.

FIG. 40 shows LC elements 12m and 1 of this embodiment.
The cross-sectional structure is 4 m, and the cross section along the spiral direction of the spiral electrode 210 is shown. As shown in the figure,
A channel 222 is formed in parallel with the spiral electrode 210, and the channel 222 makes the source 212 and the drain 214 conductive. For example, in the case of the enhancement type, the channel 22 is not provided until a voltage corresponding to the gate voltage is applied to the spiral electrode 210.
2 is formed so that the source 212 and the drain 214 are in a conductive state, but the width and depth of the channel 222 are changed by changing the gate voltage applied to the spiral electrode 210, and therefore, between the source 212 and the drain 214. The resistance value of the channel 222 can be changed.

FIG. 41 shows LC elements 12m and 1 of this embodiment.
It is a figure which shows the equivalent circuit of 4 m. In the equivalent circuit shown in FIG. 7A, a channel 222 is formed by applying a predetermined bias voltage to the spiral electrode 210, and each of them functions as an inductor having inductances L1 and L2. . Further, the spiral electrode 210 and the channel 222 form a spiral capacitor having the capacitor C.

As will be described later, a depletion type structure in which n-type carriers are preliminarily injected into the position where the channel 222 is formed may be adopted.

L of this embodiment having such an equivalent circuit
The C elements 12m and 14m function as inductor conductors having the inductance L1 because the channel 222 serving as a signal input / output path is formed in a spiral shape. Similarly,
The spiral electrode 210 functions as an inductor conductor having the inductance L2. Further, since these two inductor conductors are arranged so as to sandwich the insulating layer 226, the spiral electrode 210 and the channel 22 are provided.
2 forms a capacitor having a predetermined capacitance C in a distributed constant manner.

Therefore, this LC element 12m, 14m
Is an element in which an inductor and a capacitor are formed in a distributed constant manner, like the LC element shown in FIG.
The LC elements 12 and 14 in the sine wave oscillation circuit 1 shown in FIG. In particular, since the LC elements 12m and 14m have a MOS structure, the manufacturing process is simple, and it is convenient when integrated into an IC or an LSI.

Further, FIG. 41B shows the spiral electrode 2
10 shows a configuration in which a variable gate voltage Vg is applied to 10. The gate voltage Vg applied to the capacitor connecting electrode 28 provided at one end of the spiral electrode 210 (to be precise, in FIG. 40, the spiral electrode 2).
By changing the gate voltage applied between the substrate 10 and the substrate 224, the depth of the channel 222 changes, so the mobility of the channel 222 changes, and as a result, the resistance value of the channel 222 is arbitrarily changed. Can be made.

As a result, the frequency characteristics of the LC elements 12m and 14m also change.
When the sine wave oscillating circuit shown in FIG. 1 or FIG. 15 is configured by using 14 m, a voltage control type sine wave oscillating circuit whose oscillation frequency changes according to the applied gate voltage Vg can be easily realized. can do.

The above-mentioned LC elements 12m and 14m
Described the case where an n-channel is formed between the source 212 and the drain 214, but in this case, since electrons are used as carriers, the mobility is high and the channel 222
Resistance is reduced. On the other hand, p on the n-Si substrate
By forming the channel, the LC element 12 described above is formed.
You may make it form m and 14m. in this case,
Since the holes are used as carriers, the channel 22
The resistance of 2 becomes relatively large, and has a different characteristic as compared with the case of the n channel described above.

Further, the above-mentioned LC elements 12m and 14m
Since the spiral electrode 210 is long in the spiral direction, the potential on the substrate 224 side is set to the spiral electrode 2 in order to ensure that the channel 222 is formed.
It is necessary to set the potential lower than 10.

FIG. 42 shows the LC element 12m,
It is a figure which shows the manufacturing process of 14m, and the case of an enhancement type is shown as an example. It should be noted that the drawing shows a cross section in the spiral direction of the spiral electrode 210.

(1) Formation of Oxide Film: First, the surface of the p-Si substrate 34 is thermally oxidized to form silicon dioxide (FIG. 9 (A)).

(2) Source / Drain Window Opening: Next, the oxide film on the surface of the p-Si substrate 34 is photoetched to open windows corresponding to the source 212 and the drain 214 ( The same figure (B)).

(3) Formation of Source / Drain: Next, the source 212 and the drain 214 are formed by implanting an n-type impurity from the portion where the window is opened (FIG. 11C). For example, As ⁺ is used as the n-type impurity, and this impurity is implanted by thermal diffusion. Further, when implanting this n-type impurity by ion implantation, the window opening in (2) described above is not necessary.

(4) Removal of gate region: Next, the opening of the gate region is formed by removing the oxide film in the portion where the spiral electrode 210 is to be formed (FIG. 7D). In the case of the LC elements 12m and 14m of the present embodiment, since the spiral electrode 210 needs to be formed in a spiral shape, this gate region opening is also formed in a spiral shape. In this way, the p-Si substrate 34 is exposed only at the portion corresponding to the spiral electrode 210.

(5) Formation of Gate Oxide Film: Next, the p-Si substrate 3 partially exposed in this way
4, a new oxide film, that is, an insulating layer 226 is formed (FIG. 7E).

(6) Formation of Gate and Electrode: Next, the spiral electrode 210 functioning as a gate is formed by vapor-depositing aluminum or the like, and the input / output electrode 24 and the drain 214 connected to the source 212 are formed. Each of the connected input / output electrodes 26 is formed ((F) in the figure).

The steps of manufacturing the LC elements 12m and 14m in this manner are basically similar to the steps of manufacturing a normal MOS-FET, and it can be said that only the shape of the spiral electrode 210 is different. . Therefore, it is convenient when forming a sine wave oscillation circuit integrally forming other components such as the inverter logic circuit 10 together with the LC elements 12m and 14m on one semiconductor substrate.

The LC elements 12m and 14m of the present embodiment shown in FIG. 35 are the spiral spiral electrodes 210.
The channel 222 formed corresponding to is used as a signal input / output path, and the capacitor connecting electrodes 28 provided at one end of the spiral electrode 210 are connected directly or via the capacitor 46 and the varicap 48. However, the functions of the channel 222 and the spiral electrode 210 may be exchanged.

The LC elements 12n and 14n shown in FIG.
By connecting the input / output electrodes 24 and 26 to both ends of the spiral electrode 210, the spiral electrode 210 is used as a signal input / output path, and the source 212 (or drain 21) formed at one end of the channel 222 is used.
4) is connected with a capacitor connecting electrode 28, and when applied to the sine wave oscillation circuit 1 shown in FIG. 1 and the like, the capacitor connecting electrodes 2 of the LC elements 12n and 14n are connected.
8 to each other directly or to the capacitor 46 and the varicap 4
Connect via 8.

In general, since the resistivity of the channel 222 is higher than that of the spiral electrode 210, the channels 222 of a plurality of LC elements in the sine wave oscillation circuit 1 etc. of FIG.
In the case where the two are connected in series to form a feedback loop, the amount of attenuation of the signal voltage level becomes a problem. That is, oscillation is not continued unless the loop gain when amplified by the inverter logic circuit 10 which is an inverting amplifier is 1 or more, and therefore it is necessary to provide the inverter logic circuit 10 with an amplification factor that compensates for the attenuation due to the channel 222. . Therefore, when the sine wave oscillation circuit 1 and the like are configured using the LC elements 12m and 14m shown in FIG.
The carrier density and the like of the p-Si substrate 34 on which the elements 12m and 14m are formed are carefully examined to reduce the specific resistance of the channel 222, or to form the channel 222 with a sufficient depth, the spiral electrode 210 and the sub electrode are formed. Straight 22
It is necessary to set the reverse bias voltage (gate voltage) to be applied between 4 and 4 sufficiently large.

On the other hand, the LC element 12 shown in FIG.
n and 14n, the spiral electrode 21 is made of a metal material.
In general, 0 is formed. In this case, since the spiral electrodes 210 made of a metal material are connected in series to form a feedback loop, the specific resistance is sufficiently small, and such a problem occurs. Absent.

When the spiral electrode 210 side is used as a signal input / output path, the capacitor connecting electrode 2 is connected to either the source 212 or the drain 214.
Since 8 is connected, the other can be omitted.

The above-mentioned LC element 12m and the like have the channel 22 when the voltage level applied to the spiral electrode 210 is made relatively higher than that of the substrate 224.
Although the enhancement type element in which 2 is formed has been described, it may be a depletion type element. That is, the n-type region is formed by previously injecting carriers into the region of the channel 222 shown in FIG. 35 or 43. Thus, the channel 222 can be formed without relatively increasing the voltage level applied to the spiral electrode 210, or the relationship between the voltage level applied to the spiral electrode 210 and the channel width can be changed. Further, the carriers to be injected may be injected only into a part of the region along the spiral electrode 210.

FIGS. 44 and 45 show L shown in FIG.
FIG. 44 is a diagram showing a modification of the C elements 12m and 14m, and FIG.
Shows the LC elements 12p and 14p in which the spiral electrode 210 and the channel 222 are partially opposed to each other, and FIG. 45 shows the LC elements 12r and 14r in which the side of the spiral electrode 210 is divided into a plurality (for example, two). ing.

The LC elements 12p and 14p shown in FIG.
Is functionally the LC elements 12a and 14a shown in FIG.
The equivalent circuit shown in FIG. 11 can be applied. Similarly, the LC device 12 shown in FIG.
r and 14r are LC elements 12b and 14b shown in FIG.
13 is applicable, and the equivalent circuit shown in FIG. 13 can be applied.

As described above, even when the spiral electrode 210 and the channel 222 are partially opposed to each other or the spiral electrode 210 side is divided into a plurality of parts,
The spiral electrode 210 and the channel 222 each function as an inductor and a capacitor is formed between them in a distributed constant manner, which is applicable to the sine wave oscillator circuit 1 shown in FIG. You can Moreover, the LC elements 12m and 14 shown in FIG.
Since an LC element having a frequency characteristic different from that of m is formed,
The oscillation frequency of the sine wave oscillation circuit 1 or the like can be adjusted within a fixed range.

However, in FIG. 45, the spiral electrode 2
It is necessary to inject carriers in advance in the position of the channel 222 where 10 is not formed. Also, FIG.
When the LC element shown in FIG. 5 is configured as an enhancement type element, the channel 222 is also divided at the divided portion of the spiral electrode 210, and the feedback loop in the sine wave oscillation circuit 1 etc. shown in FIG. 1 is not formed. Therefore, in the vicinity of the surface of the p-Si substrate 34, the diffusion region 213 is formed by injecting carriers in advance at a position corresponding to this divided portion, and the divided channel 222 is formed.
Must always be available as a conductor via this diffusion region 213.

46 to 49 are views showing other examples of the LC element, and show the case where the gate electrode of the LC element of the MOS structure described above is formed in a meandering shape.

Specifically, FIG. 46 corresponds to FIG. 35, and the spiral-shaped spiral electrode 210 shown in FIG.
L having a structure in which is replaced by a meandering electrode 210a
C elements 12s and 14s are shown. This electrode 210
The channel 222 formed corresponding to a is connected in series in the plurality of LC elements to form a feedback loop in the sine wave oscillation circuit 1 and the like shown in FIG.

Similarly, FIG. 47 corresponds to FIG. 43. Contrary to the LC elements 12s and 14s shown in FIG. 46, the meandering electrode 210a side serves as a signal input / output path.
C elements 12t and 14t are shown.

FIG. 48 corresponds to FIG. 44.
The LC elements 12t and 14t in which the serpentine electrode 210a and the channel 222 are partially associated are shown.

FIG. 49 corresponds to FIG. 45.
While dividing the meandering electrode 210a side into a plurality of parts,
LC elements 12u and 14 using a channel 222 as one inductor conductor by forming a diffusion region 213 near the surface of the p-Si substrate 34 corresponding to this division position.
u is shown.

As described above, even when the electrode 210a and the channel 222 are formed in a meandering shape, each of the electrode 210a and the channel 222 functions as an inductor as shown in FIG. There is no difference in that a distributed constant capacitor is formed, and the sine wave oscillation circuit 1 and the like shown in FIG. 1 can be configured by using the LC element having such a structure. Moreover, these LC elements are MOS-mounted on the p-Si substrate 34.
The sine wave oscillation circuit can be formed by using a manufacturing technique and is suitable when integrally formed with other components (for example, the inverter logic circuit 10) such as the sine wave oscillation circuit 1 shown in FIG. Mass production and miniaturization of the whole can be easily realized.

FIG. 50 is a diagram showing another example of the LC element. 51 is an enlarged cross-sectional view taken along the line AA of FIG.
2 is an enlarged sectional view taken along line BB of FIG. 50, and FIG. 53 is C of FIG.
-C line expanded sectional view, FIG. 54 is the DD sectional expanded view of FIG.

LC elements 12v and 14v shown in these figures
Is characterized in that the LC elements 12m and 14m shown in FIG. 35 use the spiral electrode 210 as both the function of the inductor conductor and the function of the gate electrode, but separate these functions.

Specifically, the LC device 12v, 1 of this embodiment is used.
4v is a source 212 and a drain 2 formed at separate positions near the surface of the p-Si substrate 34 which is a semiconductor substrate.
14 are connected by a channel 222 formed by applying a voltage to the spiral-shaped first spiral electrode 310.

Source 212 and drain 21 described above
4 is formed as an n ⁺ region obtained by inverting the p-Si substrate 34. For example, it is formed by implanting As ⁺ ions by thermal diffusion or ion implantation to increase the impurity concentration.

The first spiral electrode 310 functions as a gate, and one end portion (outer peripheral side) of the spiral shape is a part of the source 212 and the other end portion (center side).
So that it overlaps part of the drain 214,
The insulating layer 226 formed on the surface side of the p-Si substrate 34 is sandwiched. First spiral electrode 310
Is formed, for example, by molding an aluminum film or by heavily doping P by diffusion or ion implantation.

The first spiral electrode 31 described above is also used.
The second spiral electrode 312 is formed substantially concentrically with 0. A channel 222 is formed on the surface of the p-Si substrate 34 facing the first spiral electrode 310 by applying a predetermined gate voltage between the second spiral electrode 312 and the first spiral electrode 310. It has become so.

Also, the above-mentioned first spiral electrode 31
0, the source 212, the drain 214, and the second spiral electrode 312, respectively, as shown in FIGS. 50 to 54, the capacitor connecting electrode 28, the input / output electrodes 24, 2
6, the control electrode 228 is connected. That is, the control electrode 228 is attached to the first spiral electrode 310 outside the active region so as not to damage the thin gate film, as shown in FIG. Further, the input / output electrode 24 is attached to the source 212 and the drain 2
As shown in FIGS. 54 and 52, the input / output electrode 26 is attached to the source 212 and the drain 214.
Is partially exposed, and then a metal film such as aluminum is attached. Further, like the control electrode 228, the capacitor connection electrode 28 is attached to the second spiral electrode 312 at a position separated from the active region so as not to damage the thin gate film.

Assuming that the LC elements 12v and 14v of this embodiment having the above-mentioned structure have an n-channel enhancement type structure, the first spiral electrode 3
The channel 222 is formed only when a positive voltage (voltage higher than that of the second spiral electrode 312) is applied to 10.

FIGS. 51A and 51B show channel 2
It is a figure which shows the state in which 22 is formed. When no positive gate voltage is applied to the first spiral electrode 310, that is, to the control electrode 228 connected to the first spiral electrode 310, as shown in FIG. The channel 222 does not appear on the surface of the substrate 34. Therefore, in this state, the source 2 shown in FIG.
12 and the drain 214 are in an insulated state.

However, when a relatively positive gate voltage is applied to the first spiral electrode 310, FIG.
As shown in (B), a channel 222 consisting of an n region appears near the surface of the p-Si substrate 34 corresponding to the first spiral electrode 310. Further, inside the p-Si substrate 34 and outside the channel 222, a depletion layer in which holes are eliminated by the positive gate voltage applied to the first spiral electrode 310 is formed. Therefore, the electrons in the channel 222 and the holes in the p-Si substrate 34 are arranged to face each other with the depletion layer in between, and the channel 222 and the p-Si substrate 34 existing outside the channel 222 with the depletion layer in between. Form a capacitor. In addition, since this capacitor is formed over substantially the entire length of the first spiral electrode 310, the second spiral electrode 312 connected to the p-Si substrate 34 and the channel 222 have a spiral shape in a distributed constant manner. A capacitor will be formed.

FIG. 55 shows LC elements 12v, 1 of this embodiment.
It is a figure which shows the equivalent circuit of 4v. In the equivalent circuit shown in the figure, a channel 222 is formed by applying a predetermined gate voltage to the control electrode 228, and the channel 222 is formed.
Is used for the signal input / output path. When the sine wave oscillation circuit 1 shown in FIG. 1 is formed using the LC elements 12v and 14v having such an equivalent circuit,
The channels 222 are connected in series to form a feedback loop, and the capacitor connecting electrode 28 provided at one end of the second spiral electrode 312 is directly connected (or via the capacitor 46 or the varicap 48).

Note that a different gate voltage may be applied to each LC element in consideration of the voltage drop due to the channel 222.

In the LC elements 12v and 14v of this embodiment having such a structure, the channel 222 functions as an inductor conductor having the inductance L1, and
The second spiral electrode 312 functions as an inductor conductor having the inductance L2. Further, a capacitor having a predetermined capacitance C is formed in a distributed constant manner between these two inductor conductors. Therefore,
These LC elements 12v and 14v have basically the same frequency characteristics as the LC element shown in FIG. 2 and the like, and can be used in the sine wave oscillation circuit 1 and the like shown in FIG.
In addition, as in the LC element 12m shown in FIG.
Since it has a structure, the process can be simplified by the MOS manufacturing technology, and it can be integrally formed on the p-Si substrate 34 together with other components, which facilitates mass production and miniaturization. Can be realized.

56 and 57 show the L shown in FIG.
It is a figure which shows the modification of C element 12v, 14v. FIG. 56
The second spiral electrode 312 and the channel 222 are formed by shortening the second spiral electrode 312.
LC elements 12w and 14w in which and are partially opposed to each other are shown. Further, FIG. 57 shows the second spiral electrode 31.
LC element 12x obtained by dividing 2 into a plurality of pieces (for example, two pieces),
14x is shown.

58 to 60 are diagrams showing other modifications of the LC elements 12v and 14v shown in FIG.
Each of the LC elements shown in these figures has a channel 22.
The feature is that the functions of the second spiral electrode 312 and the second spiral electrode 312 are exchanged, and the second spiral electrode 312 is used as a signal input / output path (feedback loop). 58 corresponds to FIG. 50, FIG. 59 corresponds to FIG. 56, and FIG. 60 corresponds to FIG. 57.

For example, when the second spiral electrode 312 is formed of a metal material and the second spiral electrode 312 is used as a part of the feedback loop in the sine wave oscillation circuit 1 shown in FIG. There is little attenuation of the voltage level in this feedback loop, and there is an advantage that the amplification factor of the inverting amplifier such as the inverter logic circuit 10 shown in FIG. 1 can be set low. This advantage is the same as that of the LC elements 12n and 14n shown in FIG.

FIG. 61 is a diagram showing a partial modification of the LC element shown in FIG. 50 and subsequent drawings, and shows a sectional structure corresponding to FIG. 51. Specifically, as shown in FIG. 61A, an inversion layer 232 formed of a spiral p-type region along the first and second spiral electrodes 310 and 312 is formed in a part of the n-Si substrate 144. Has been done. In the LC element having such a cross-sectional structure, when a predetermined gate voltage is applied to the control electrode 228 provided at one end of the first spiral electrode 310, as shown in FIG. N corresponding to the first spiral electrode 310
A channel 222 is formed near the surface of the Si substrate 144. Moreover, by applying a reverse bias voltage between the n-Si substrate 144 and the inversion layer 232, the spiral inversion layer 232 is electrically separated from each other in each winding portion, and the channel 222 and the second layer are separated from each other. Spiral electrode 3
A distributed constant capacitor is surely formed between the capacitor 12 and the capacitor 12.

62 to 68 show L shown in FIG. 50 and thereafter.
It is a figure which shows the modification of a C element, and the case where the 1st and 2nd spiral electrodes 310 and 312 arrange | positioned substantially parallel are arrange | positioned substantially opposite on both sides of the p-Si substrate 34 is shown.

FIG. 62 corresponds to FIG. 50, and has a channel 222 having a spiral shape and the second spiral electrode 31.
An LC element in which 2 and 2 are formed to have almost the same length is shown. 63 is an enlarged sectional view taken along the line AA of FIG. 62 and corresponds to the sectional structure shown in FIG. 51. The LC elements 12y and 14y of the present embodiment have the first and second spiral electrodes 310, 14y as shown in the sectional structure of FIG.
312 are formed so as to face each other with the p-Si substrate 34 sandwiched therebetween, and a channel 222 formed corresponding to the first spiral electrode 310 and a second channel formed on the back surface of the p-Si substrate 34. A spiral-shaped capacitor is formed by the spiral electrode 312 in a distributed constant manner.

FIG. 64 corresponds to FIG. 56, and p
An LC element is shown in which first and second spiral electrodes 310 and 312, which are arranged to face each other with a Si substrate 34 interposed therebetween, are partially opposed to each other. Further, FIG. 65 corresponds to FIG. 57, and the second spiral electrode 31 formed so as to substantially face the first spiral electrode 310.
An LC element obtained by dividing 2 into a plurality of pieces (for example, two pieces) is shown.

In each of the LC elements shown in FIGS. 62, 64, and 65, the channel 222 side is used as a signal input / output path, and the feedback loop of the sine wave oscillation circuit shown in FIG. Although a part is formed, this feedback loop may be formed by using the second spiral electrode 312 side as a signal input / output path. 66 shows a case where the channel 222 and the second spiral electrode 312 are formed to have substantially the same length, and FIG. 67 shows a case where the channel 222 is formed to have a relatively short length so as to partially face each other.
Reference numeral 8 indicates that the first spiral electrode 310 is divided into a plurality of pieces (for example, two pieces), so that the channel 222 formed correspondingly is also divided into a plurality of pieces.

FIG. 69 is a diagram showing a partial modification of the LC element in which the first and second spiral electrodes 310 and 312 are arranged substantially opposite to each other with the p-Si substrate 34 interposed therebetween. Specifically, the first and second spiral electrodes 3
A spiral-shaped inversion layer is formed between the circumferential portions of 10, 312. That is, as shown in FIG.
A spiral inversion layer composed of an n region 234 is formed on a part of the i substrate 34. In the LC element having such a structure, the second spiral electrode 312 having a different lap portion is provided.
Focusing on the p-Si substrates 34 connected to each other, since the n regions 234 are formed between them, they are electrically separated from each other, so that it is possible to reliably perform the isolation of each lap portion.

In addition, p-Si which is actually in a wafer state
In the case of manufacturing the above-described LC element using the substrate 34, the thickness of the p-Si substrate 34 is set to be smaller than the thickness of the wafer in consideration of the fact that the specific resistance of the p-Si substrate 34 is higher than that of a general metal. It needs to be thinner than the condition. In addition, as described above, the structure shown in FIG. 70 may be used in consideration of the fact that n-type wafers are generally easier to obtain.

That is, as shown in FIG.
Spiral etching is performed on one surface of the Si substrate 144, and the first or second etching is performed on the etched portion.
Spiral electrodes 310 and 312 are formed. Further, as shown in FIG. 7B, ap ⁺ region 236 is formed on a part of the n-Si substrate 144 so as to substantially follow the first and second spiral electrodes 310 and 312, respectively, and then n
-A portion of the back surface of the Si substrate 144 corresponding to the second spiral electrode 312 is etched, and finally the first and second spiral electrodes 310 and 312 are formed.

By shortening the interval between the first and second spiral electrodes 310 and 312 formed so as to face each other in this manner, the channels 222 which face each other are substantially faced.
A distributed constant capacitor is formed only between the second spiral electrode 312 and the second spiral electrode 312. Moreover, as shown in FIG. 3B, the first and second spiral electrodes 3
When the inversion layer is formed in the portion sandwiched between 10, 312, the pnp structure is formed in contact with different winding portions of the second spiral electrode 312, so that good isolation is performed in each winding portion. .

Further, in the LC element described in each of the drawings after FIG. 50 described above, the first and second spiral electrodes 310 and 312 are both formed in a spiral shape, but these are formed in a meandering shape. You may. FIG. 71
~ Fig. 82 shows the first and second spiral electrodes 3 described above.
10 and 312 are replaced with first and second electrodes 310a and 312a having a meandering shape, and a channel 222 and a second electrode 312a formed corresponding to the first electrode 310a having a meandering shape are formed. Each of them functions as an inductor conductor, and a distributed constant capacitor is formed between them.

More specifically, FIG. 71 shows first and second electrodes 310a, 310a having substantially the same length and formed in parallel.
An LC element having 12a and using the channel 222 side as a signal input / output path is shown. In FIG. 72, the second
The LC element is shown in which the first electrode 312a is formed short and the first and second electrodes 310a and 312a are partially opposed to each other. FIG. 73 shows an LC element in which the second electrode 312a is divided into a plurality of pieces (for example, two pieces). Further, in each of FIGS. 74 to 76, the L
An LC element in which the functions of the channel 222 of the C element and the second electrode 312a are exchanged is shown. Furthermore, FIG.
In each of FIG. 82, the second electrode 312a is provided with p-Si.
FIG. 77 shows FIG. 71, FIG. 78 shows FIG. 72, FIG. 79 shows FIG. 73, FIG. 79 shows FIG. 73, and FIG. 80 shows FIG. 74. , Fig. 8
1 corresponds to FIG. 75, and FIG. 82 corresponds to FIG.

Each of the LC elements described above is characterized in that a distributed constant capacitor is formed by partially utilizing the inside of the semiconductor substrate, and the entire LC element can be manufactured by using a semiconductor manufacturing technique. is there. On the other hand, although the semiconductor substrate is used in the same manner, the LC element can be formed by stacking a plurality of inductor conductors on the surface without using the inside thereof.

FIG. 83 is a schematic diagram showing another modification of the LC element.

The LC elements 12z and 14z shown in the figure include a high-purity semiconductor substrate 320 and two spiral electrodes 322 and 324 which are formed substantially on this surface. The first spiral electrode 322 corresponds to the first spiral electrode 20 shown in FIG. 2, for example,
The second spiral electrode 324 corresponds to the second spiral electrode 22 shown in FIG. An insulating film (not shown) is formed between the first and second spiral electrodes 322 and 324.

Therefore, the first spiral electrode 322
By providing terminals corresponding to the input / output electrodes 24 and 26 shown in FIG. 2 at both ends of the first spiral electrode 32,
2 can be made to function as one inductor conductor. Further, since the second spiral electrode 324 is formed so as to overlap the first spiral electrode 322, a distributed constant capacitor is formed between these two spiral electrodes 322 and 324, and these inductor components The relationship between the capacitor component and the capacitor component is shown in FIG.
It is exactly the same as 2.

Therefore, the LC element 12z, shown in FIG.
As shown in FIG. 1, the spiral electrodes 322 of 14z are connected in series to form a feedback loop, and one ends of the second spiral electrodes 324 are directly connected or connected via a capacitor 46 and a varicap 48. It is possible to obtain a sine wave oscillating circuit similar to the sine wave oscillating circuit 1 and the like.

In particular, the LC elements 12z, 1 shown in FIG.
Since 4z is formed by using the semiconductor substrate 320, it is possible to integrally form other components (for example, the inverter logic circuit 10 etc.) shown in FIG. 1 on the semiconductor substrate 320. Mass production and miniaturization can be easily realized.

FIG. 84 shows an LC whose schematic structure is shown in FIG.
It is a figure which shows an example of the manufacturing process of an element. The figure shows the sectional structure of the LC elements 12z and 14z in the order of each step.

(1) A high-purity semiconductor substrate 320 is prepared ((A) in the figure). When the semiconductor substrate 320 has a low purity, it can be used as an insulating substrate by forming an oxide film or the like on the surface thereof.

(2) A metal film is formed on the semiconductor substrate 320, and, for example, an aluminum film 324a is deposited (FIG. 2B). Note that the metal film may be formed of another material such as gold or copper.

(3) A pattern of a spiral photoresist 330a is formed on the aluminum film 324a (FIG. 7C). The formation of this pattern can be performed by, for example, a photo-etching method.

(4) Using the photoresist 330a as a mask, the aluminum film 324a is partially removed to form the second spiral electrode 324 (FIG. 7 (D)). Then, the photoresist 324a is washed off.

(5) The end portion (end portion on the outer peripheral side) of the second spiral electrode 324 thus formed is masked with the photoresist 330b (FIG. 7E).

(6) Anodization is performed to form an insulating oxide film 326 on the surface of the remaining portion (the portion not masked) of the second spiral electrode 324 (FIG. 7F).

(7) Again, a metal film is formed on the entire surface, for example, an aluminum film 322a is vapor-deposited ((G) in the same figure).

(8) Lead-out electrode 3 formed on the aluminum film 322a at the end of the spiral spiral photoresist pattern 330c and the second spiral electrode 324.
A pattern of photoresist 330d corresponding to No. 28 is formed ((H) in the figure). The formation of this pattern can be performed, for example, by the photolithography method as in the case of the photoresist 330a described above.

(9) These photoresists 330c,
The first spiral electrode 322 is formed by partially removing the aluminum film 332a using 330d as a mask.
And the extraction electrode 328 is formed at the end of the lower second spiral electrode 324. Then, the photoresists 330c and 330d are washed off.

FIG. 85 is a diagram showing the planar shapes of the LC elements 12z and 14z formed on the semiconductor substrate 320 through these steps. As shown in FIG.
In the C elements 12z and 14z, the first spiral electrode 322 is formed on the surface, and the extraction electrode 328 provided at the end of the second spiral electrode 324 is exposed. The lead electrode 328 corresponds to the capacitor connecting electrode 28 shown in FIG. 2, and both ends of the first spiral electrode 322 are 2 shown in FIG.
It corresponds to each of the one input / output electrodes 24 and 26.

FIG. 86 shows an LC whose schematic structure is shown in FIG.
It is a figure which shows the other example of the manufacturing process of an element. According to the manufacturing process shown in FIG. 84, the two spiral electrodes 322, 3
Insulating oxide film 3 formed between 24 by anodic oxidation
An LC element for insulation is manufactured by 26.
According to the manufacturing process shown in FIG.
The difference is that an LC element is manufactured by replacing the element with a silicon oxide film formed by a chemical vapor deposition method (CVD). The manufacturing process will be described below.

(1) A high-purity semiconductor substrate 320 is prepared ((A) in the figure). Then, a first silicon oxide film 340 is formed on the semiconductor substrate 320 by the chemical vapor deposition method (FIG. 2B). However, a high-purity semiconductor substrate 320
Since the specific resistance is high in the case of using, the first silicon oxide film 340 can be omitted.

(2) On the first silicon oxide film 340,
A metal film 324b made of a metal, such as gold, tungsten, molybdenum, tantalum, or niobium, which can withstand the next chemical vapor deposition process is vapor-deposited (FIG. 7C).

(3) A spiral photoresist pattern 330a is formed on the metal film 324b (FIG. 3D). The formation of this pattern can be performed by, for example, a photo-etching method.

(4) Using the photoresist 330a as a mask, the metal film 324b is partially removed to form the second spiral electrode 324 (FIG. 7E). Then, the photoresist 330a is washed off.

(5) A second silicon oxide film 342 is formed on the second spiral electrode 324 and the exposed first silicon oxide film 340 by the chemical vapor deposition method (FIG. 7F). .

(6) A metal film 322b is vapor-deposited on the second silicon oxide film 342 ((G) in the figure). Since there is no chemical vapor deposition process in the subsequent process, this metal film 322b
Can be an aluminum film, but may be formed of another metal material such as gold or copper.

(7) A spiral photoresist pattern 330c is formed on the metal film 322b (FIG. 7 (H)). The formation of this pattern can be performed, for example, by the photolithography method as in the case of the photoresist 330a described above.

(8) Using this photoresist 330c as a mask, the first spiral electrode 322 is formed (FIG. 11 (I)). Then, the photoresist 330c is washed off.

By using such a process as well,
The LC elements 12z and 14z having a planar structure shown in FIG. 85 can be manufactured. As described above, since the LC elements 12z and 14z of the present embodiment described above are formed on the surface of the semiconductor substrate 320, other semiconductor devices such as the sine wave oscillation circuit 1 shown in FIG. Components (for example, the inverter logic circuit 10) can be formed, and mass production by integral formation and miniaturization of the entire circuit can be easily realized.

The LC elements 12z and 14z whose schematic structure is shown in FIG. 83 have the first and second spiral electrodes 3a and 3b.
Although the electrodes 22 and 324 are formed in a spiral shape having substantially the same length, these two electrodes may be partially opposed to each other, or the second spiral electrode 324 side may be divided into a plurality of parts. Further, two electrodes having not only the spiral shape but also the meandering shape as shown in FIG. Furthermore, not only the first and second spiral electrodes 322 and 324 are made to face each other, but also the center of each winding portion of the other electrode is positioned between the winding portions of one electrode to partially make the first electrode.
Alternatively, the second spiral electrodes 322 and 324 may be stacked.

The present invention is not limited to the above embodiments, but various modifications can be made within the scope of the gist of the present invention.

For example, in each of the above-mentioned embodiments, two LC elements 12 and 14 (or LC elements 12a and 14a) in which inductors and capacitors are distributedly formed.
Although a) and the like are connected in a ring shape, three or more LC elements may be connected.

FIG. 87 is a diagram showing the structure of a sine wave oscillation circuit using three LC elements. Basically, FIG.
The LC element 1 is added to the sine wave oscillation circuit 2a whose configuration is shown in FIG.
3 shows a configuration in which 3 is added. As shown in FIG. 87,
Although the capacitor connecting electrode 28 of the LC element 13 is opened and the LC element 13 is mainly used as an inductor element, the capacitor connecting electrodes 28 of the LC elements 12, 13 and 14 are directly connected to each other or between them. The capacitor 4
6 or the burr cap 48 may be used for connection. Further, not only the sine wave oscillating circuit 2a shown in FIG. 8 (A) but also L used in the sine wave oscillating circuit of another embodiment.
The number of C elements may be three or more.

Further, in each of the above-described embodiments, two (or three or more LC elements) having almost the same structure are used.
Although a case has been described as an example where a sine wave oscillation circuit is configured by using, the LC elements having different structures may be combined in one sine wave oscillation circuit. For example, both cases of combining LC elements having similar structures as shown in FIGS. 2 and 10 and cases of combining LC elements having different structures as shown in FIGS. 2 and 22 are possible.

Further, in each of the LC elements described above, the electrodes and channels functioning as inductor conductors are formed in a spiral shape or a meandering shape. This spiral shape also includes ones having a number of turns of about one turn or less than one turn. The meandering shape also includes a non-linear shape with a waveform or the number of irregularities of 1 or 2, depending on the size of the inductance.
The electrode shape of the LC element used can be appropriately selected.

Further, although the LC element of each of the above-mentioned embodiments is mainly formed by using the p-Si substrate, it is similarly formed by using the n-type semiconductor substrate (n-Si substrate). Good. The semiconductor substrate may be made of a material other than silicon such as germanium, or amorphous silicon which is an amorphous material.

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[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a sine wave oscillator circuit of a first embodiment to which the present invention is applied.

FIG. 2 is a diagram showing an example of an LC element.

3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is a diagram showing an equivalent circuit of the LC element shown in FIG.

FIG. 5 is a diagram showing a specific configuration for applying a bias voltage to an LC element in a sine wave oscillation circuit.

FIG. 6 is a diagram showing a manufacturing process of the LC element shown in FIG.

FIG. 7 is a diagram showing general characteristics of a distributed constant type LC element.

FIG. 8 is a diagram showing a modification of the first embodiment.

FIG. 9 is a diagram showing another modification of the first embodiment.

FIG. 10 is a diagram showing a modification of the LC element shown in FIG.

11 is a diagram showing an equivalent circuit of the LC element shown in FIG.

FIG. 12 is a diagram showing another modification of the LC element.

13 is a diagram showing an equivalent circuit of the LC element shown in FIG.

FIG. 14 is a diagram showing a connection example of the LC element shown in FIG.

FIG. 15 is a diagram showing a configuration of a sine wave oscillator circuit according to a second embodiment of the present invention.

FIG. 16 is a diagram showing a modification of the second embodiment.

FIG. 17 is a diagram showing another modification of the second embodiment.

FIG. 18 is a diagram showing another modification of the second embodiment.

FIG. 19 is a diagram showing a configuration of a sine wave oscillator circuit according to a third embodiment of the present invention.

FIG. 20 is a diagram showing a modification of the third embodiment.

FIG. 21 is a diagram showing another modification of the third embodiment.

FIG. 22 is a diagram showing a modified example of the LC element.

23 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 24 is a diagram showing another modification of the LC element.

FIG. 25 is a diagram showing another modification of the LC element.

FIG. 26 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 22.

FIG. 27 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 22.

FIG. 28 is a diagram showing another modification of the LC element.

FIG. 29 is a diagram for explaining the operation of the inductor conductor having a meandering shape.

FIG. 30 is a diagram showing another modification of the LC element.

FIG. 31 is a diagram showing another modification of the LC element.

FIG. 32 is a diagram showing another modification of the LC element.

FIG. 33 is a diagram showing another modification of the LC element.

FIG. 34 is a diagram showing another modification of the LC element.

FIG. 35 is a diagram showing another modification of the LC element.

36 is an enlarged cross-sectional view taken along the line AA of FIG. 35.

37 is an enlarged cross-sectional view taken along the line BB of FIG. 35.

38 is an enlarged cross-sectional view taken along the line CC of FIG.

39 is a diagram for explaining a state in which a channel is formed in the LC element shown in FIG.

40 is a diagram showing a cross section taken along a spiral electrode of the LC element shown in FIG. 35.

41 is a diagram showing an equivalent circuit of the LC element shown in FIG. 35.

42 is a diagram showing a manufacturing process of the LC element shown in FIG. 35. FIG.

FIG. 43 is a diagram showing another modification of the LC element.

FIG. 44 is a diagram showing another modification of the LC element.

FIG. 45 is a diagram showing another modification of the LC element.

FIG. 46 is a diagram showing another modification of the LC element.

FIG. 47 is a diagram showing another modification of the LC element.

FIG. 48 is a diagram showing another modification of the LC element.

FIG. 49 is a diagram showing another modification of the LC element.

FIG. 50 is a diagram showing another modification of the LC element.

51 is an enlarged cross-sectional view taken along the line AA of FIG.

52 is an enlarged sectional view taken along the line BB of FIG. 50.

53 is an enlarged cross-sectional view taken along the line CC of FIG.

54 is an enlarged cross-sectional view taken along line DD of FIG.

55 is a diagram showing an equivalent circuit of the LC element shown in FIG. 50.

FIG. 56 is a diagram showing another modification of the LC element.

FIG. 57 is a diagram showing another modification of the LC element.

FIG. 58 is a diagram showing another modification of the LC element.

FIG. 59 is a diagram showing another modification of the LC element.

FIG. 60 is a diagram showing another modification of the LC element.

61 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 50.

FIG. 62 is a diagram showing another modification of the LC element.

63 is a diagram for explaining a state in which a channel is formed in the LC element shown in FIG. 62.

FIG. 64 is a diagram showing another modification of the LC element.

FIG. 65 is a diagram showing another modification of the LC element.

FIG. 66 is a diagram showing another modification of the LC element.

FIG. 67 is a diagram showing another modification of the LC element.

FIG. 68 is a diagram showing another modification of the LC element.

69 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 62.

FIG. 70 is a diagram showing a partial modification of the cross-sectional structure of the LC element shown in FIG. 62.

FIG. 71 is a diagram showing another modification of the LC element.

FIG. 72 is a diagram showing another modification of the LC element.

FIG. 73 is a diagram showing another modification of the LC element.

FIG. 74 is a diagram showing another modification of the LC element.

FIG. 75 is a diagram showing another modification of the LC element.

FIG. 76 is a diagram showing another modification of the LC element.

FIG. 77 is a diagram showing another modification of the LC element.

FIG. 78 is a diagram showing another modification of the LC element.

FIG. 79 is a diagram showing another modification of the LC element.

FIG. 80 is a diagram showing another modification of the LC element.

FIG. 81 is a diagram showing another modification of the LC element.

FIG. 82 is a diagram showing another modification of the LC element.

FIG. 83 is a diagram schematically showing another modification of the LC element.

84 is a diagram showing an example of a manufacturing process of the LC element shown in FIG. 83. FIG.

85 is a plan view of the LC element shown in FIG. 83. FIG.

86 is a diagram showing another example of the manufacturing process of the LC element shown in FIG. 83. FIG.

FIG. 87 is a diagram showing a configuration of a sine wave oscillation circuit using three LC elements.

[Explanation of symbols]

1 Sine wave oscillator 10 Inverter logic circuit 12,14 LC element 16 capacitors 20 First spiral electrode 22 Second spiral electrode 24,26 Input / output electrodes 28 Electrode for connecting capacitors 34 p-Si substrate (p-type silicon substrate) 36 pn junction layer

Continuation of front page (51) Int.Cl. ⁷ identification code FI H01L 27/04 H01L 27/04 L H03B 5/08 H01G 4/40 A H03H 5/02 (56) Reference JP-A-4-179306 (JP , A) JP-A-3-215917 (JP, A) JP-A-3-211810 (JP, A) JP-A-6-13677 (JP, A) JP-A-6-21533 (JP, A) JP-A-6-21533 6-77711 (JP, A) JP-A-6-152300 (JP, A) JP-A-4-196804 (JP, A) JP-A-7-303009 (JP, A) Jitsuko Sho-44-11699 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03B 5/00-5/18 H01F 17/00 H01F 27/00 H01G 4/40 H01L 21/822 H01L 27/04 H03H 5/02

Claims (31)

(57) [Claims] 1. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to generate a sine wave. A sine wave oscillating circuit for oscillating a wave, wherein the LC elements are arranged substantially concentrically adjacent to each other in the same plane, and each of the spiral-shaped two LC elements functions as the two inductor conductors.
One electrode, and a position near the surface of the semiconductor substrate and along the two electrodes, and one of these two electrodes is electrically connected to the p region and the other is electrically connected to the n region. ,
A sine-wave oscillation circuit comprising: a spiral pn junction layer that operates as the capacitor by applying a reverse bias voltage. 2. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to generate a sine wave. A sine wave oscillating circuit for oscillating waves, wherein the LC elements are arranged substantially opposite to each other with the semiconductor substrate interposed therebetween,
Two spiral-shaped electrodes functioning as the two inductor conductors, and a p region formed in a position sandwiched between the two electrodes in the semiconductor substrate, and a p region is formed on one of the two electrodes. A sine-wave oscillating circuit, wherein the n region is electrically connected to the other side, and the spiral pn junction layer operates as the capacitor by applying a reverse bias voltage. 3. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to generate a sine wave. A sine wave oscillating circuit for oscillating a wave, wherein the LC elements are arranged substantially parallel and adjacent to each other in the same plane, and the two meandering electrodes functioning as the two inductor conductors, It is formed in the vicinity of the surface of the semiconductor substrate and along the two electrodes, and one of these two electrodes is electrically connected to the p region, and the other is electrically connected to the n region,
A meandering pn junction layer that operates as the capacitor by applying a reverse bias voltage, and a sine wave oscillation circuit. 4. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to generate a sine wave. A sine wave oscillating circuit for oscillating a wave, wherein the LC elements are arranged to face each other with the semiconductor substrate sandwiched therebetween, and two serpentine electrodes functioning as the two inductor conductors, and the semiconductor It is formed in the substrate at a position sandwiched by the two electrodes, and a p region is electrically connected to one of these two electrodes and an n region is electrically connected to the other of the two electrodes, and a reverse bias voltage is applied. A sine-wave oscillating circuit, comprising: a spiral pn junction layer that operates as the capacitor. 5. The sinusoidal oscillator circuit according to claim 1, wherein one of the two electrodes is formed to have a shorter length than the other. 6. The method according to claim 1, wherein one of the two electrodes that functions as the other inductor is divided into a plurality of pieces, or one of the two electrodes that functions as the other inductor is provided. The sine wave oscillation circuit, wherein the pn junction layer is divided into a plurality of parts, one end side of each divided piece is connected between the plurality of LC elements, and the other end side is electrically opened. 7. The capacitance value of a capacitor formed in a distributed constant in the LC element according to claim 1, wherein a reverse bias voltage applied to the pn junction layer is changed. A sine wave oscillator circuit characterized by. 8. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to generate a sine wave. A sine wave oscillating circuit for oscillating waves, wherein the LC element has a spiral electrode forming a gate in a MOS structure, and an insulating layer formed between the spiral electrode and the semiconductor substrate. First and second diffusion regions formed in the semiconductor substrate near both ends of a channel formed corresponding to the spiral-shaped electrode and functioning as a source and a drain. The sine wave oscillating circuit characterized in that each of the electrodes and the channel formed corresponding thereto functions as the two inductor conductors and the channel is used as the signal input / output path. 9. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to generate a sine wave. A sine wave oscillating circuit for oscillating waves, wherein the LC element has a spiral electrode forming a gate in a MOS structure, and an insulating layer formed between the spiral electrode and the semiconductor substrate. A first diffusion region formed in the semiconductor substrate near one end of a channel formed corresponding to the spiral electrode and functioning as a source or a drain; And a channel formed corresponding to each of the channels functions as the two inductor conductors, and the spiral electrode is used as the signal input / output path. 10. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillation circuit that oscillates a chord wave, wherein the LC element includes a meandering electrode that forms a gate in a MOS structure, and an insulating layer that is formed between the meandering electrode and the semiconductor substrate. A first and a second diffusion region formed in the semiconductor substrate in the vicinity of both ends of a channel formed corresponding to the meandering electrode and functioning as a source and a drain. A sinusoidal oscillator circuit characterized in that each of the shaped electrodes and the channels formed corresponding thereto function as the two inductor conductors, and that the channels are used as the signal input / output paths. 11. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillation circuit that oscillates a chord wave, wherein the LC element includes a meandering electrode that forms a gate in a MOS structure, and an insulating layer formed between the meandering electrode and the semiconductor substrate. A first diffusion region formed in the semiconductor substrate in the vicinity of one end of a channel formed corresponding to the serpentine electrode and functioning as a source or a drain. A sine wave oscillation circuit characterized in that each of the electrodes and the channel formed corresponding thereto functions as the two inductor conductors, and that the meandering electrodes are used as the signal input / output paths. . 12. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit that oscillates a chord wave, wherein the LC element is a spiral first coil forming a gate in a MOS structure.
Electrode, an insulating layer formed between the spiral-shaped first electrode and the semiconductor substrate, and formed on the surface of the semiconductor substrate and concentrically adjacent to the first electrode. A spiral-shaped second electrode; first and first electrodes formed in the semiconductor substrate near both ends of a channel formed corresponding to the spiral-shaped first electrode and functioning as a source and a drain. Two
And a channel formed corresponding to the spiral-shaped first electrode and the second electrode each functioning as the two inductor conductors. A sine wave oscillation circuit characterized by being used as a signal input / output path. 13. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit that oscillates a chord wave, wherein the LC element is a spiral first coil forming a gate in a MOS structure.
Electrode, an insulating layer formed between the spiral-shaped first electrode and the semiconductor substrate, and formed on the surface of the semiconductor substrate and concentrically adjacent to the first electrode. A spiral-shaped second electrode, and a first electrode formed in the semiconductor substrate near one end of a channel formed corresponding to the spiral-shaped first electrode and functioning as a source or a drain. And a channel formed corresponding to the spiral-shaped first electrode and the second electrode each functioning as the two inductor conductors, and the second electrode. Is used as the signal input / output path. 14. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit that oscillates a chord wave, wherein the LC element includes: a meandering first electrode forming a gate in a MOS structure; and a meandering first electrode between the first electrode and the semiconductor substrate. A formed insulating layer; a meandering second electrode formed on the surface of the semiconductor substrate so as to be adjacent to and substantially parallel to the first electrode; A first and a second diffusion region formed near both ends of a channel formed corresponding to the first electrode having a shape and functioning as a source and a drain. A sine wave oscillating circuit, wherein each of the correspondingly formed channel and the second electrode functions as the two inductor conductors, and the channel is used as the signal input / output path. 15. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit for oscillating a chord wave, wherein the LC element includes: a meandering first electrode forming a gate in a MOS structure; and a meandering first electrode between the semiconductor electrode and A formed insulating layer; a meandering second electrode formed on the surface of the semiconductor substrate so as to be adjacent to and substantially parallel to the first electrode; A first diffusion region formed near one end of a channel formed corresponding to the first electrode having a shape and functioning as a source or a drain, and corresponding to the first electrode having a meandering shape. A sine wave oscillating circuit characterized in that each of the formed channel and the second electrode functions as the two inductor conductors, and the second electrode is used as the signal input / output path. 16. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit that oscillates a chord wave, wherein the LC element is formed on one surface side of the semiconductor substrate, and has a spiral-shaped first electrode that forms a gate in a MOS structure, and the spiral-shaped first electrode. An insulating layer formed between the first electrode and the semiconductor substrate, and a spiral-shaped second formed on the other surface side of the semiconductor substrate at a position substantially facing the first electrode. Electrode and first and second electrodes formed in the semiconductor substrate near both ends of a channel formed corresponding to the first electrode having a spiral shape and functioning as a source and a drain.
And a channel formed corresponding to the spiral-shaped first electrode and the second electrode respectively function as the two inductor conductors, and the channel is provided with the signal input. A sine wave oscillation circuit characterized by being used as an output path. 17. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit that oscillates a chord wave, wherein the LC element is formed on one surface side of the semiconductor substrate, and has a spiral-shaped first electrode that forms a gate in a MOS structure, and the spiral-shaped first electrode. An insulating layer formed between the first electrode and the semiconductor substrate, and a spiral-shaped second formed on the other surface side of the semiconductor substrate at a position substantially facing the first electrode. And a first diffusion region in the semiconductor substrate, which is formed near one end of a channel formed corresponding to the spiral-shaped first electrode and functions as a source or a drain. A channel formed corresponding to the spiral-shaped first electrode and the second electrode each function as the two inductor conductors, and the second electrode serves as the signal input / output path. Sine wave oscillator circuit, characterized in that it uses. 18. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit for oscillating a chord wave, wherein the LC element is formed on one surface side of the semiconductor substrate and has a meandering first electrode forming a gate in a MOS structure, and the meandering shape of the first electrode. An insulating layer formed between the first electrode and the semiconductor substrate, and a meandering second formed on the other surface side of the semiconductor substrate at a position substantially facing the first electrode. Electrode, and first and second diffusion regions formed in the semiconductor substrate near both ends of a channel formed corresponding to the meandering first electrode and functioning as a source and a drain. , And a channel formed corresponding to the first electrode having a meandering shape and the second electrode each function as the two inductor conductors, and use the channel as a signal input / output path. Sine wave oscillator circuit, wherein the door. 19. An inverting amplifier for amplifying an input signal and performing phase inversion, and two inductor conductors formed substantially in parallel on a semiconductor substrate, and two inductors formed by these two inductor conductors. And a plurality of LC elements in which capacitors between them are formed in a distributed constant, wherein one of the two inductor conductors is used as a signal input / output path in the plurality of LC elements. At the same time, one of the inductors used as the signal input / output path is connected in series with each other, and the output of the inverting amplifier is fed back to the input side through the series connection circuit, and further functions as the signal input / output path. Not connect one end side of the other inductor to a given potential side, electrically open the other end side, and operate the plurality of LC elements as a resonance circuit to make them positive. A sine wave oscillating circuit for oscillating a chord wave, wherein the LC element is formed on one surface side of the semiconductor substrate, and has a meandering first electrode forming a gate in a MOS structure; An insulating layer formed between the first electrode and the semiconductor substrate, and a meandering second formed on the other surface side of the semiconductor substrate at a position substantially facing the first electrode. And a first diffusion region in the semiconductor substrate, which is formed near one end of a channel formed corresponding to the meandering first electrode and functions as a source or a drain. A channel formed corresponding to the first electrode having a meandering shape and the second electrode function as the two inductor conductors, and the second electrode is used as a signal input / output path. What to do Sine wave oscillator circuit, characterized. 20. The carrier according to any one of claims 8 to 11, wherein carriers are previously injected into at least a part of a position near the surface of the semiconductor substrate where the channel is formed, and the spiral shape or the meandering shape is formed. A sinusoidal oscillation circuit, wherein the spiral or meandering electrode and the channel are partially opposed to each other by setting the length of the channel longer or shorter than the electrode. 21. The spiral or meandering shape of the second electrode according to claim 12, wherein the length of one of the first and second electrodes is shorter than that of the other. A sine wave oscillator circuit characterized in that the electrode and the channel are partially opposed to each other. 22. The LC element according to claim 8, wherein carriers are previously injected into a position near the surface of the semiconductor substrate where the channel is formed. 23. Claims 13, 15, 17, 19, 2
1 or 22, in the case where the channel formed corresponding to the first electrode is used as the other inductor, the first electrode is divided into a plurality of the first electrodes. The plurality of LC elements are connected to each other and the diffusion regions formed near one end of each divided channel are connected to each other, and the channel formed corresponding to A sine wave oscillator circuit characterized by electrically opening the diffusion region. 24. The method according to claim 12, 14, 16, 18, or 2.
1 or 22, in the case where the second electrode is used as the other inductor, the second electrode is divided into a plurality of pieces, and one end vicinity of each divided electrode piece is provided with the plurality of LC elements. A sine wave oscillating circuit characterized by being connected to each other and electrically opening the other ends. 25. The sinusoidal wave according to claim 8, wherein a resistance value of the channel is variably controlled by changing a gate voltage applied to an electrode forming the gate. Oscillator circuit. 26. The sine wave oscillation circuit according to claim 1, wherein the oscillation frequency is switched by changing the operating power supply voltage of the inverting amplifier. 27. In any one of claims 1 to 26, the LC element and the inverting amplifier, or in addition to these, the frequency adjusting capacitor or the varicap is integrally formed on the common semiconductor substrate. Characteristic sine wave oscillator circuit. 28. The frequency adjusting device according to any one of claims 1 to 27, wherein the plurality of LC elements are two, and the two inductors of the two LC elements are arranged between one ends of the other inductor. A sine wave oscillation circuit characterized by being connected via a capacitor. 29. In any one of claims 1 to 27, the plurality of LC elements are two, and a varicap is provided between one end sides of two inductors of the two LC elements. A sine wave oscillating circuit characterized by being connected through. 30. The sine wave oscillation circuit according to claim 1, wherein the inverting amplifier is composed of an inverter logic circuit. 31. The sine wave oscillation circuit according to claim 1, wherein the inverting amplifier is constituted by a grounded source circuit or a grounded emitter circuit.