JPH0744289B2 - Base modulation bipolar phototransistor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a base modulation type bipolar phototransistor having a negative resistance characteristic.

[Prior Art] Conventionally, photodiodes, phototransistors, photodarlington transistors, and the like are well known as photoelectric conversion devices, and are extremely widely used in various industrial fields. However, among the photoelectric conversion devices described above, the photodiode is excellent in response speed, but has a drawback of poor sensitivity, and the phototransistor is excellent in sensitivity, but slow in response, Although the dark current is poor, the photo Darlington transistor is extremely excellent in sensitivity, but has the drawback that the response is extremely slow and the dark current is extremely poor. Further, the saturation voltage V _CE (sat) between the collector and the emitter of the photo Darlington transistor is about 0.6 V higher than that of the photo transistor. On the other hand, these photoelectric conversion devices have a linear output signal with respect to the optical input, and most of them, except for the photodiode, convert to a pulse signal for the purpose of being used as an ON-OFF switch operation. is there. Therefore, in this type of photoelectric conversion device, it is common to perform waveform shaping by a Schmitt trigger circuit or the like so that there is no problem such as chattering, which leads to an increase in the number of parts and causes a high cost. In addition, current consumption is also required. Therefore, development of an optical bistable device for the purpose of optical communication is active, but an expensive compound semiconductor is used as a material, and the bistable operation itself is a limited region.
It was not for practical use yet. In addition, the photo thyristor that switches to the optical input can be switched off even if it can be controlled to switch on under DC bias.
It is impossible to control the switch operation of
Most of them were used under AC bias.

From the above, under the above-mentioned conventional technology, the sensitivity and the output current are high with respect to the optical input, the response is excellent, the bistable switch operation is possible under the DC bias, the manufacturing is easy, and the cost is low. It is strongly desired to develop a new photoelectric conversion device.

[Problems to be Solved by the Invention] Therefore, the present invention solves various problems found in the above-described conventional photoelectric conversion device, meets the above-mentioned demands, and enables various operations. It is to provide a base modulation type bipolar phototransistor having a new negative resistance characteristic.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention specifically provides a collector region made of a semiconductor material of a first conductivity type and a first PN for the collector region. A base region made of a semiconductor material of a second conductivity type formed through a junction, and an emitter region made of a semiconductor material of a first conductivity type formed at a second PN junction with respect to the base region. And wherein the base region is the second region relative to the emitter region.
A first base region that is adjacent to the first base region via a PN junction, and forms a wide-area light receiving portion with a distance from the first base region, and a base electrode is formed in a part of the light receiving portion. A second base region provided, and a third base region having a low impurity concentration formed between the first base region and the second base region, the first base region And a gate region having a first conductivity type in the third base region between the second base region and the second base region, wherein the collector region and the gate region are connected to the second base region. The region is biased in a reverse bias state, and a depletion layer penetrating into the third base region from the collector region and a depletion layer penetrating into the third base region from the gate region are used to 2 base areas When a region is irradiated with light, a light input current generated near the PN junction between the second base region and the collector region and flowing toward the emitter region is modulated, and a negative resistance characteristic to the light input is obtained. A base modulation type bipolar phototransistor is constructed so as to obtain an output having.

[Operation] The base-modulation-type bipolar phototransistor according to the present invention, which is configured as described above, receives a light bias when a reverse bias higher than a certain voltage is applied to the collector region and the gate region with respect to the second base region. The base-emitter is forward-biased by the input, the minority carriers injected into the third base region are absorbed in the depletion layer from the collector region or the gate region, and the light input causes the second base region to flow from the collector region. The majority carriers that have been injected into the third base region after that are also suppressed from being injected into the third base region. In this way, the third base region is modulated by the reverse bias voltage of the collector region or the gate region and the second base region, the optical input current is modulated, and the amplified collector current and gate current are amplified. Indicates a negative resistance characteristic.

Further, in the base modulation type bipolar phototransistor according to the present invention, the negative resistance light characteristic can be freely set and controlled by the base terminal, and the negative resistance light characteristic can be freely set and controlled also at the gate terminal. be able to.

[Embodiment of the Invention] The base-modulation bipolar phototransistor according to the present invention will be described below.
tor: BAMBIT) will be described in detail based on specific examples shown in the drawings. In the description of the embodiments of the present invention, an NPN semiconductor device will be exemplarily described when silicon is used as a semiconductor material. However, the present invention can be applied to other compound semiconductors as a semiconductor material, and can also be configured as a PHP type semiconductor device.

In the present invention, the first embodiment of the photo / BAMB
A schematic sectional view of IT is shown in FIG. 1, and a schematic plan view thereof is shown in FIG. In FIG. 1, first, N ⁺
N ^- collector layer (2) 10 on high impurity concentration substrate (1)
Epitaxial growth is performed with an impurity concentration of about ¹⁵ atoms / cm ³ to a thickness of about 5 to ¹⁵ μm. Then, a P ^- base layer (3) is epitaxially grown on the upper surface of the N ^- collector layer (2) to an impurity concentration of about 10 ¹⁶ atoms / cm ³ and a thickness of about 1 to 3 μm. Next, using the P ⁻ base layer as a base region, diffusion or ion implantation is performed at an impurity concentration of about 10 ²⁰ atoms / cm ³ to separate it from the N ⁻ collector layer (2) to form an N ⁺ region (4). A P ⁺ base region (5) is diffused or ion-implanted into a part of the isolated P ⁻ base layer (3) to an impurity concentration of about 10 ¹⁸ atoms / cm ³ . This P ⁺
The base region (5) is the first base region. Then, the P ^- the base region (3), said first base region from (5) P ^- separated by a base region (3a), to form a P ⁺ base region (6). The P ⁺ base region (6) may be formed at the same time as the first P ⁺ base region (5). On the other hand, both the P ⁺ base region (5) and the P ⁺ base region (6) may have a depth reaching the N ⁻ collector layer (2), and in some cases, the N ⁺ collector region (2). ^- it may be of depth not reaching the collector layer (2). The P ⁺ base region (6) is used as a second base region, and the P ⁻
The base region (3a) is the third base region. continue,
The N ⁺ emitter region (7) is formed inside the P ⁺ base region (5) by selecting the impurity concentration and depth so as to obtain a desired current amplification factor h _FE . Subsequently, N ⁺ gate region (8)
Surrounded by P ⁺ base region (5) and P ⁺ base region (6)
It is formed by diffusion or ion implantation so as to surround the P ⁺ base region (5) in the P ⁻ base region (3a). At this time, the impurity concentration and the depth of the gate region (8) are one of the steps that influence the characteristics of the photo / BAMBIT in the present invention, and in order to obtain a desired value of the characteristics described later, the impurity concentration of the P ^- base region is increased. It is determined in consideration of concentration and thickness, impurities in the N ⁻ collector region, and the like. Also, depending on the target negative resistance characteristics and current amplification factor h _FE in the above process,
Simultaneous formation of the emitter region (7) and the N ⁺ region (4) and simultaneous formation of the emitter region (7) and the N ⁺ gate region (8) are possible. Then, by known techniques, P ⁺ base region (6), N ⁺ emitter region (7) and N ⁺ gate region (8)
On the other hand, a hole for each contact is provided, and an electrode is formed of a desired metal material such as aluminum. Each electrode is a base electrode (10) for the P ⁺ base region (6), an emitter electrode (11) for the emitter region (7), and a collector electrode (1 for the collector region (1).
2) and the gate electrode (13) for the gate region (8). Lithography, passivation, and the like may be formed by a conventionally known technique between the above steps.

Next, the operation principle of the photo-BAMBIT according to the first embodiment as shown in FIGS. 1 and 2 will be described. First, for the purpose of making it easier to understand the operating principle,
A case where light is not emitted to BAMBIT, and a case where the BAMBIT is connected as shown in the base ground connection diagram of FIG. 3 and operated by electric input will be described. Note that FIG. 3 is a grounded base circuit diagram similar to that of a normal transistor, showing that the gate potential is the same as the collector potential, and the NPN according to the present invention is distinguished from a normal NPN transistor.
-For the photo and BAMBIT, a new symbol mark is used. It is also shown that the base-emitter is forward-biased with a resistor r _EB , and the collector and gate are reverse-biased with a voltage V _CB with respect to the base. The current that flows at this time is the collector current I _C , the gate It is shown by current I _G , base current I _B , and emitter current I _E.

In FIG. 1, the base electrode (10) and collector electrode (1
2) and the gate electrode (13) are set to the same potential or a low reverse bias state, and a forward bias is applied to the base electrode (11) via the resistor r _EB . Then, electrons, which are minority carriers, are injected from the emitter region (7) into the P ⁺ base region (5), and most of them are drawn into the N ⁻ collector region (2) as in a normal transistor, and the collector current is collected. It becomes I _C , and partly becomes the gate current I _G. on the other hand,
From P ⁺ base region (5) or P ^- base region (3a) to P ⁺
A part of the electrons recombines to reach the base region and becomes the base current I _B. On the other hand, holes are injected into the P ^- base region (3a) from the P ⁺ base region in order to capture holes that are majority carriers recombined with electrons. As a result, immediately below the gate region (8), electrons that have not yet been recombined and holes that have already recombined and supplemented with them coexist. When the voltage V _CB is gradually increased from this state, the depletion layer gradually enters the P ⁻ base region (3a) at the collector-base junction J _CB2 . Also, the gate
Since the N ⁺ / P ^- junction is formed at the base junction, the depletion layer almost extends to the P ^- base region (3a).
As a result, the ratio of electrons injected from the emitter region (7) to the gate region (8) and the N ⁻ collector region (2) increases. That is, for minority carriers, the base current I _B due to recombination is decreased, the collector current I _C is increased, the current amplification factor h _FE is increased, and the gate current I _G is also increased. To work. That is, it works to increase the current amplification factor h _FE ′ with respect to the sum of the collector current I _C and the gate current I _G. In the embodiment as shown in FIG. 1, I _C >> I _G and h _FE ′ h _FE because of the structure.

On the other hand, for holes injected from the P ⁺ base region (6), the depletion layer that enters the P ⁻ base region (3a) is a junction field effect transistor (hereinafter referred to as J-FET). It works in the same way as in the case of reducing the free charge region, suppressing injection by holes, reducing recombination current, and reducing collector current and gate current. Then, the depletion layers from the gate region (8) and the N ⁻ collector region (2) stick to each other and work to pinch off. However, the recombination current due to holes does not decrease gradually. that is,
In the connection diagram shown in FIG. 3, for holes, the P ⁺ base region (6) acts as the source of the J-FET, and the P ⁺ base region (5) acts as the drain. ⁺ Compared to the saturation current value I _BP (sat) for the hole when the potential is the same as that of the base region (6), the base current I _B is maintained at a low value with a high resistance load that is approximately h _FE ′ times the resistance r _EB. ,
The voltage between the collector and the gate and the base V _CB causes I
_{This is because BP} (sat) cannot be reduced to the base current value at that time. Further, when the voltage V _CB between the collector and the gate and the base is increased to reach the pinch-off voltage, the recombination current due to holes, that is, the base current I _B is cut off. At this time, the voltage between the collector and the gate, and the base
V _CB becomes smaller the lower the pinch-off voltage, the larger the ratio of base current to saturation current value, I _B / I _BP (sat),
In addition, the lower the pinch-off voltage, the smaller I _B / I _BP (sat), and the higher the current amplification factor, the sharper the cutoff.

As described above, the invasion of the depletion layer from the gate region (8) and the N ^- collector region (2) to the P ^- base region (3a) causes current amplification to minor carriers before recombination. It acts to increase the rate h _FE ′, but moreover, to majority carriers, it acts to decrease the base current itself, limiting the total amount of minority carriers injected from the emitter region. To work. By this action,
With respect to the reverse bias voltage between the collector and the gate and the base, the P ^- base region (3a) is modulated and the base current is modulated to exhibit the negative resistance characteristic and cut off. The amplified collector current and gate current also show negative resistance characteristics and are cut off. At this time, the conductivity modulation effect of the minority carriers injected into the P ^- base region (3a) is also involved.

FIG. 4 shows the electrical input / output characteristics of the photo / BAMBIT in the base ground connection shown in FIG. As shown in Fig. 4, the voltage V _CB at which the characteristic changes is V _CB (ON), V
_{When CB} (OFF), as long as the gate voltage is fixed, the negative resistance characteristic is reversible, and the output current (I _C + I _G )
On the other hand, V _CB (ON) hardly changes, and a slight change in the voltage between the collector and the gate and the base V _CB V _CB (OFF) -V
_CB (ON) ≈ 0.4V, turning on and off. This is because the base current value is sufficiently lower than the saturation current value for holes which are the majority carriers between the P ⁺ base light receiving region (6) and the P ⁺ base region (5) as described above, and the gate region ( 8) and the collector-base junction J _CB2 absorbs electrons which are minority carriers and the current amplification factor h _FE ′ increases.

Next, this photo / BAMBIT will be described with reference to FIG. 5 based on the operation principle for light input in the grounded emitter and the electrical input / output characteristics in the grounded base. FIG. 5 shows a base, similar to the connection mode shown in FIG.
Although it is connected via the resistor r _BE between the emitters, first,
In Fig. 5, the base terminal is open, that is, the resistor
and disconnect through r _BE, described similar operation state and normal photo-transistor.

When the base is open and the P ⁺ base light receiving area is irradiated with light, holes generated in the vicinity of the collector-base junction J _CB1 are accumulated in the P ⁺ base light receiving area (6), and electrons are collected in the collector. Accumulated in the area. The P ⁺ base light receiving region (6) is at a positive potential with respect to the collector region and the gate region, and also with respect to the emitter region. When the collector and gate voltages are raised by V _{CE with} respect to the emitter from this state, electrons, which are minority carriers, are injected from the emitter region (7) into the P ⁺ base region (5) by the photocurrent amplification effect. As explained in the grounded base, most of the injected electrons follow the path and are absorbed in the N ^- collector region (2), resulting in the collector current I _CEL ,
A part of it becomes the gate current I _GEL due to the route. Then, by the route, some electrons are recombined with holes from the P ⁺ base region (5) or the P ⁻ base region (3a) to the P ⁺ base light receiving region (6). The holes recombined with the electrons are complemented by holes of majority carriers injected into the P ⁺ base light-receiving region (6) by light.
There is a flow of light input current to the light input from the collector region (2) through the P ⁺ base light receiving region (6) to the emitter region (7) according to the illuminance, which is the P ⁺ base light receiving region ( 6) and the area of the junction J _CB1 between the collector region (2) and I _CBL ″ = 0 and I _CBL ′ = I _CBL when the base is open in FIG. (Where I _CBL is the optical input current generated at the collector-base junction J _CB1 , I _CBL ′ is the optical input current input to the emitter,
I _CBL ″ is the photocurrent flowing to the resistance r _BE side, and I _CBL =
I _CBL ′ + I _CBL ″), and this optical input current
I _CBL ′ = I _CBL is amplified and becomes the photo BAMBIT output current (I _CEL + I _GEL ) for the optical input, and I _CEL + I _GEL = I _CBL ′ ×
h _FE ′ + I _CBL .

Here, in the case of the conventional phototransistor, the base voltage of the light receiving portion is almost fixed to the rising voltage between the base and the emitter with respect to the increase of the voltage V _CE . However,
In the case of this photo BAMBIT, as the voltage V _CE increases,
Rising voltage V _F (B, E) between the base and emitter and when, V _CE is V _F (B, E) than the voltage becomes, between the collector and the gate and the base is reverse biased. And the voltage V
_CE reaches V _CE = V _F (B, E) + V _CB (ON), and the collector current I _CEL and the gate current I _GEL tend to exhibit negative resistance characteristics as described in the base grounding characteristics. However, since the P ⁺ base light-receiving region (6) is in the open state, the potential of the P ⁺ base light-receiving region (6) rises as the voltage V _CE increases. The electric potential of the P ⁺ base light-receiving area (6) is V _CE
Changes to the potential of V _CE −V _CB (ON) with an increase in the voltage from the collector region (2) to the P ⁺ base light receiving region (6).
A light input current I _CBL ′ = I _CBL depending on the illuminance that reaches the emitter region (7) through the current always flows regardless of the voltage V _CE .
Therefore, when the P ⁺ base light receiving portion region (6) is open, the amplified output current (I _CEL + I _GEL ) does not exhibit the negative resistance characteristic.

Therefore, next, during light irradiation, the collector-gate-to-emitter voltage V _CE is increased with respect to the collector-gate-to-base V
A case where a high resistance of about 100 KΩ or more is inserted between the base and the emitter as the resistance r _BE as shown in FIG. 5 so that a reverse bias voltage of _CB (OFF) or more is applied will be described. In Fig. 5, the voltage V _CE rises and V _CE
When becomes V _F (B, E), the collector and gate are reverse-biased, as is the case when the base is open. From V _CE = V _CE (ON) ≈ V _F (B, E) + V _CB (ON), as explained in the grounded base, electrons that are minority carriers are more absorbed by the collector and gate regions, and current amplification is performed. Increase the rate. On the other hand, N ^- than the collector region (2), through the P ⁺ base receiving region (6) P ^- holes that are majority carriers which are injected by light in the base region (3a), the injection is suppressed. As a result, the optical input current I _CBL ′ reaching the emitter region (7) decreases and the amplified output current (I _CEL + I
_GEL ) also decreases. This reduced optical input current is
_It flows into the _BE side as I _CBL ″ and raises the base voltage V _B. Further, when the voltage V _CE is increased, the optical input current I _CBL ′ inputted to the emitter is further reduced and the amplified output current ( I _CEL + I _GEL ) also decreases to show a negative resistance characteristic, and the voltage V _CE is V _CE = V _CE (OFF) = V _CB (OFF) + I _CBL
X r _BE side, all optical input current I _CBL goes to resistance r _BE side
As I _CBL ″, I _CBL is not amplified as the output of the photo / BAMBIT, and only I _CBL is output through the resistor r _BE .

FIG. 7 shows the situation when the illuminance (lx) is used as a parameter. As is clear from this figure, the input / output characteristics of the grounded emitter with respect to light, V _CE (ON), as well as V _CB (ON), hardly change with respect to the collector current. Also in this case, P ⁺
The light input current value is lower than the saturation current value for the hole between the base light receiving region (6) and the P ⁺ base region (5), and the gate region (8) and collector-base junction J _CB2
Absorbs electrons that are minority carriers and increases the current amplification factor. Further, in FIG. 8, the output current (I _CEL + I _GEL ) in the active area of the photo-BAMBIT is represented by (I _CEL +
I _GEL ) ≈ I _CBL ′ × h _FE ′, the optical input current I _CBL ′ flowing into the photo / BAMBIT side is I _CBL ′ ≈ (I _CBL −V _F (B,
E) / r _BE ), so for the optical input current I _CBL , I
_CEL + I _GEL ≈ (I _CBL −V _F (B, E) / r _BE ) × h _FE ′,
The negative resistance value R _N in the negative resistance region is Can be expressed as From the equation (1), it can be seen that increasing the resistance r _BE increases I _CEL but also increases V _CE (OFF). This is shown in FIG. Further, the characteristic curve group shown in FIG. 7 and FIG. 8 can be further changed by the gate voltage.
-It can be understood from 196627. A photo / BAMBIT having such a negative resistance characteristic, even if a load R _L is connected to the collector as a two-terminal connection as shown in FIG. 9 as a basic circuit example, | R _N of the above formula (1) Compared with |, if R _L > | R _N | is satisfied, a bistable output with a hysteresis characteristic is obtained for the optical input as shown in FIG. The optical input value when the switch is turned on in Fig. 10 is I _CBL × r _BE ＞ V _CC −V _CB (OF
It is a value that satisfies F). Also, as shown in FIG. 11, the base terminal is made to have a constant voltage through the resistor r _BE , and as shown in FIG. It is also possible to obtain high output. Moreover, even if a load is connected to the emitter side with r _BE >> _{R L} as shown in Fig. 12, a bistable output with hysteresis for the optical input can be obtained. Furthermore, this invention
BAMBIT enables high-frequency oscillation by optical input simply by connecting a capacitor C ₁ like the example circuit of FIG. 13, and the oscillation frequency can be modulated by the optical input intensity.

Next, a second embodiment of the photo-BAMBIT according to the present invention will be described with reference to FIG. The photo-BAMBIT according to the second embodiment has a P ^- base region formed by ion implantation. In FIG. 14, first, an N ⁻ collector layer (2) is epitaxially grown on an N ⁺ high impurity concentration substrate (1), and a P ⁺ base region (5) and an N ⁻ collector layer (2) are formed on the N ⁻ collector layer (2). The P ⁺ base light receiving area (6) is formed by diffusion or ion implantation. Then P ^- region (3c)
Between the P ⁺ base light receiving region (6) and the P ⁺ base region (5) with an impurity concentration of about 10 ¹⁶ atoms / cm ³ by ion implantation to a thickness of about 1 to ³ μm. Then, the emitter region (7) is formed by diffusion or ion implantation so as to obtain a desired current amplification factor h _FE . Also in the second embodiment, the impurity concentration of the N ⁻ collector layer (2), the impurity concentration and depth of the P ⁻ base region (3c), the N ⁺ gate region (8)
As for the impurity concentration and the depth, the values may be determined according to the target negative resistance characteristic, as shown in the first embodiment. Also, the target negative resistance characteristics and current amplification factor h
Depending on the _FE , the emitter region (7) and the N ⁺ gate region (8) can be simultaneously formed. In addition, formation of each electrode, lithography between steps, passivation and the like are performed by known techniques. According to this manufacturing process,
The P ⁻ base region (3b) can be eliminated, and in some cases, it is not necessary to surround the P ⁺ base region (5) with the P ⁻ base region (3c), and a large chip size can be reduced.

Furthermore, a third embodiment of the photo / BAMBIT according to the present invention will be described with reference to FIG. The photo / BAMBIT according to the third embodiment is the same as that of the second embodiment.
The high resistance r _BE described with reference to FIG. 5 can be formed in the same chip as the high resistance region (14). Further, also in the first embodiment, it is possible to incorporate a high resistance body.

In addition, as shown in Japanese Patent Application No. 63-196627 of the same applicant, the photo / BAMBIT which is the invention has the structure of the gate portion.
It is also possible to use a MOS structure, a short key structure, or the like, and the same applies when a compound semiconductor is applied. In the photo BAMBIT, the higher the impurity concentration of the N ^- collector region (2), the lower the impurity concentration of the P ^- base region (3a), or the deeper the depth of the N ⁺ gate region (8). 、、
Both V _CB (ON) and V _CB (OFF) become low, and collector and P
^- the base region (3a) and between the gate and the P ^- base region (3a)
By using the built-in voltage V _i between them, even if the collector and gate and the light receiving part of the P ⁺ base are externally at the same potential, the P ⁻ base region (3a) near the gate region (8) is
It is also possible to use a normal / OFF type optical switch that can be turned on by light irradiation, by depleting and turning off the state.

[Advantages of the Invention] The base modulation type bipolar transistor of the present invention having the above configuration
The phototransistor has many operational effects as shown below.

(I) Since the photo / BAMBIT has a negative resistance characteristic, there is no post-processing circuit, and the circuit configuration is extremely simple.
Bistable switch operation with hysteresis is possible with two terminals for optical input.

(Ii) Due to the characteristics of the element itself, bistable switching operation is possible, so that current consumption as in the case of using an integrated circuit is not required.

(Iii) When the switch is turned on, V _CE (sat) is equivalent to that of a normal bipolar phototransistor.

(Iv) Excess minority carriers due to light input can be rapidly absorbed by the depletion layer from the collector region and the gate region,
Enables high-speed switch operation.

(V) In the switch OFF state, the leak current from the light receiving portion is not amplified, so the leak current value is low, and the leak current does not significantly increase due to the temperature rise that has been a problem in the conventional phototransistor.

(Vi) Since the photo / BAMBIT has a negative resistance characteristic, high frequency relaxation oscillation is possible by optical input even with a simple circuit configuration.

(Vii) Depending on the depth of the gate region, etc., it is possible to design a normal-off type optical switch that facilitates memory operation for optical input.

(Viii) By using the gate terminal, the negative resistance characteristic can be changed, the light input value for turning on the switch can be changed, and the switching speed can be improved.

(Ix) Like the conventional phototransistor, it can have high sensitivity and high terminal voltage.

(X) It can be manufactured by a process similar to that of a conventional phototransistor, is easy to manufacture, and is low in cost.

[Brief description of drawings]

1 is a schematic sectional view showing a concrete first embodiment of a base modulation type bipolar phototransistor according to the present invention, and FIG. 2 is a schematic plan view of the embodiment shown in FIG. FIG. 3 is a circuit diagram showing a base-grounded connection agent to show the characteristics of the base modulation type bipolar phototransistor with respect to an electric input, and FIG. 4 is a base-grounded characteristic curve with respect to an electric input of FIG. FIG. 5 is an operation principle diagram showing an enlarged example of FIG. 1 for explaining the operation principle of the base modulation type bipolar phototransistor, and FIG. 6 is a diagram showing the base modulation type bipolar phototransistor. FIG. 7 is a circuit diagram showing a grounded-emitter connection example of FIG. 1, and FIG.
A second grounded-emitter characteristic curve diagram when the base-emitter resistance is fixed and the light input is used as a parameter, and FIG. 8 shows the grounded-emitter connection example shown in FIG.
The second grounded-emitter characteristic curve diagram when the light input is constant and the resistance between the base and emitter is used as a parameter. Fig. 9 shows a load connected to the base modulation type bipolar phototransistor, FIG. 10 is a circuit diagram showing a first connection example for obtaining a bistable output, FIG. 10 is a graph showing an output characteristic example with respect to an optical input in the circuit example shown in FIG. 9, and FIG. 11 is the base modulation type. A circuit diagram showing a second connection example for connecting a load to a bipolar phototransistor and obtaining a bistable output with respect to an optical input. Fig. 12 shows a load connected to the base modulation type bipolar phototransistor. , A circuit diagram showing a third connection example for obtaining a bistable output with respect to an optical input, and FIG. 13 shows a high frequency relaxation oscillation with respect to an optical input by connecting a load to the base modulation type bipolar phototransistor. output FIG. 14 is a circuit diagram showing a connection example for obtaining the same, FIG. 14 is a schematic sectional view showing a second embodiment of a base modulation type bipolar phototransistor according to the present invention, and FIG. 15 is a base according to the present invention. A third embodiment of the modulation type bipolar phototransistor, which is a schematic view showing an example in which a high resistance body is arranged between the base and the emitter and is formed in the same element in the second embodiment. FIG. (1), (2) ... collector region (3) ... base region (3a) ... third base region (4) ... N ₊ region (5) ... first base region (6) ... … Second base region (7) …… Emitter region (8) …… Gate region (9) …… Oxide film (10) …… Base electrode (11) …… Emitter electrode (12) …… Collector electrode (13) ) …… Gate electrode (14) …… Base-emitter resistance (15) …… Ground electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 29/73 7210-4M H01L 27/14 K

Claims (1)

[Claims] 1. A collector region made of a semiconductor material of a first conductivity type, and a base region made of a semiconductor material of a second conductivity type formed in the collector region via a first PN junction. An emitter region made of a semiconductor material of a first conductivity type formed via a second PN junction with respect to the base region, the base region having a second region with respect to the emitter region;
A first base region that is adjacent to the first base region via a PN junction, and forms a wide-area light receiving portion with a distance from the first base region, and a base electrode is formed in a part of the light receiving portion. A second base region provided, and a third base region having a low impurity concentration formed between the first base region and the second base region, the first base region And a gate region having a first conductivity type in the third base region between the second base region and the second base region, wherein the collector region and the gate region are connected to the second base region. The region is biased in a reverse bias state, and a depletion layer penetrating into the third base region from the collector region and a depletion layer penetrating into the third base region from the gate region are used to 2 base areas When a region is irradiated with light, a light input current generated near the PN junction between the second base region and the collector region and flowing toward the emitter region is modulated, and a negative resistance characteristic to the light input is obtained. A base modulation type bipolar phototransistor characterized in that an output having the above is obtained.