JPH0821355B2 - High energy ion implanter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion implanting device for implanting ions into a semiconductor substrate or the like, and particularly to an ion beam of mega-electron volt (hereinafter referred to as MeV) grade high energy and large current. The present invention relates to a high energy ion implanting device suitable for implanting.

[0002]

2. Description of the Related Art MeV-class high-energy ion implantation is an essential means for high integration of semiconductor devices in the future, as a means for doping impurities into a deep layer in a semiconductor substrate (hereinafter referred to as a substrate). Particularly in the ion implantation into a silicon wafer with a resist, it is necessary to perform high energy ion implantation while maintaining the substrate temperature at 100 ° C. or lower. Conventionally, in order to realize such implantation, a high-energy ion implantation apparatus equipped with a high frequency quadrupole accelerator has been developed.

A conventional high-energy ion implanter equipped with a high-frequency quadrupole accelerator is disclosed in Japanese Patent Application No. 58-22.
As described in Japanese Patent No. 6860 and Japanese Patent Application No. 58-226861, accelerated MeV, milliampere (hereinafter,
There is a method in which an ion beam of a grade (mA) is introduced into one ion implantation chamber to perform an ion implantation operation. The ion implantation chamber is several tens of keV and several tens.
A general-purpose ion-implantation chamber of the rotating disk type for the mA ion beam is used.

[0004]

However, in the above-mentioned conventional high-energy ion implantation apparatus, the temperature of the substrate to be ion-implanted (hereinafter referred to as "sample substrate") is raised by the beam irradiation, so that the sample substrate temperature is 100%.
In order to keep the temperature below 0 ° C., it was necessary to limit the practical maximum beam power introduced into the driving chamber to about 2 kW. The beam power corresponds to the product of the beam current value and the beam energy.

On the other hand, since the conventional driving chamber is a vacuum, the cooling efficiency by heat conduction is generally different from the cooling in the atmosphere. For this reason, even if the sample substrate is closely attached to the water-cooled rotary disk, it is necessary to keep the sample substrate temperature during ion implantation at 100 ° C. or less for the beam power of 2 kW or more in the conventional technique. It is difficult with the device.

The conventional high-frequency quadrupole accelerator is several mA to several tens of meters as described in the above-mentioned known example.
It is an accelerator that basically has the capability of efficiently accelerating the ion beam of A in the high energy region of MeV class. However, when an ion beam is introduced into a conventional ion implantation chamber, the beam current is limited to 2 mA for a 1 MeV beam and 1 mA for a 2 MeV beam, for example, due to the limitation of temperature rise due to the beam power.

The present invention provides a high-energy ion implanter capable of performing ion implantation with a high-energy MeV-class ion beam with a large current without increasing the temperature of the sample substrate above a predetermined value. The purpose is to

[0008]

The high-energy ion implantation apparatus of the present invention has four electrodes having a wavy shape along the axial direction and introduces an ion beam into the central portion of the positions of these four electrodes. High frequency quadrupole accelerator for accelerating the ion beam, an ion beam injection system for introducing the ion beam into the high frequency quadrupole accelerator, and a beam for deflecting the ion beam emitted from the high frequency quadrupole accelerator. It is characterized by having a deflector and a plurality of ion implantation chambers for performing ion implantation using the ion beam that has passed through the beam deflector.

Further, the high energy ion implantation apparatus of the present invention is characterized in that the beam deflector deflects the ion beam accelerated by the high frequency quadrupole accelerator in a plurality of directions and distributes the ion beam to a plurality of ion implantation chambers. To do.

Further, in the high-energy ion implantation apparatus of the present invention, each of the ion implantation chambers in the plurality of ion implantation chambers rotates a water-cooled rotary disk on which a sample to be ion-implanted is mounted on the surface. And a water-cooled rotary disk drive mechanism that reciprocates the water-cooled rotary disk in the radial direction.

Further, the high energy ion implantation apparatus of the present invention is characterized by having a pulse adjuster for changing the pulse width and the repetition period of the deflection voltage for controlling the beam deflector.

Further, in the high energy ion implanting apparatus of the present invention, the pulse adjuster changes the pulse width and the repetition period of the deflection voltage in accordance with the period of the high frequency high voltage driving the high frequency quadrupole accelerator. Characterize.

Further, in the high energy ion implantation apparatus of the present invention, the pulse adjuster changes the pulse width and the repetition period of the deflection voltage in accordance with the voltage value of the high frequency high voltage for driving the high frequency quadrupole accelerator. Is characterized by.

[0014]

In the high energy ion implanter of the present invention, the beam deflector deflects the ion beam emitted from the high frequency quadrupole accelerator in the direction according to the applied deflection voltage. Then, the deflection voltage applied to the beam deflector is controlled to distribute the ion beam emitted from the high frequency quadrupole accelerator to a plurality of ion implantation chambers. In each ion implantation chamber, the introduced ion beam collides with the sample substrate or the like, thereby implanting ions into the sample substrate or the like.

As described above, in the high-energy ion implantation apparatus of the present invention, the ion beam emitted from the high frequency quadrupole accelerator is dispersed in the plurality of ion implantation chambers, so that the temperature rise of the sample substrate can be avoided. Therefore, the ion implantation can be performed with the maximum beam current of the high frequency quadrupole accelerator.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of the main part of a high energy ion implantation apparatus according to the first embodiment of the present invention. The high-energy ion implanter of this embodiment comprises a high frequency quadrupole accelerator 1, a beam deflector 2, ion implant chambers 3a, 3b and 3c, a deflection voltage generator 5 and a pulse adjuster 6. Further, as shown in FIG. 1, a sample substrate 4 which is a substrate into which ions are implanted.
a, 4b, 4c, 4d, 4e and 4f are mounted in the ion implantation chambers 3a, 3b and 3c, respectively.

The high frequency quadrupole accelerator 1 accelerates an ion beam incident from an ion beam injection system including an ion source, a mass separator, a magnetic field lens, etc., to generate high frequency power supplied to the high frequency quadrupole accelerator 1. A high-energy ion beam corresponding to the above is used. Further, the high frequency quadrupole accelerator 1 has four quadrupole electrodes having a corrugated shape along the axial direction, and a high frequency high voltage is applied to these electrodes, and at the same time, the central portion of the quadrupole is ion-charged. It is an accelerator that introduces a beam to accelerate the ion beam. The beam deflector 2 changes the emitting direction of the ion beam emitted from the high frequency quadrupole accelerator 1. The ion implantation chambers 3a, 3b, 3c respectively introduce the ion beams deflected by the beam deflector 2 and direct the ion beams to the sample substrates 4a, 4b, 4c, 4d, 4e, 4f installed therein. It is a room for irradiation and ion implantation. The deflection voltage generator 5 generates a deflection voltage for controlling the deflection operation of the beam deflector 2. The pulse adjuster 6 outputs a pulse whose pulse width and pulse interval are arbitrarily set to the deflection voltage generator 5 to control the operation of the deflection voltage generator 5.

Next, the operation of this embodiment will be described.
The ion beam incident on the high-frequency quadrupole accelerator 1 is accelerated and applied with a large amount of energy. Further, since the high frequency quadrupole accelerator 1 exerts a bunching action on the incident ion beam, the accelerated ion beam is emitted from the high frequency quadrupole accelerator 1. Then, the massive ion beam is sequentially emitted from the high-frequency quadrupole accelerator 1 at high-frequency periodic intervals. FIG. 2A is a graph showing an example of the state of the ion beam emitted from the high frequency quadrupole accelerator 1.

The massive ion beam emitted from the high frequency quadrupole accelerator 1 is incident on the beam deflector 2. The beam deflector 2 deflects the incident lump-shaped ion beam, and the lump-shaped ion beams are individually injected into the ion implantation chamber 3
Allocate to a, 3b, and 3c. The deflection voltage applied to the beam deflector 2 for such distribution is output from the deflection voltage generator 5 with a characteristic as shown in FIG. 2B, for example. That is, at time t ₁ , the deflection voltage V ₁ is applied to the beam deflector 2 to guide the ion beam incident at time t ₁ to the implantation chamber 3a. Next, at time t ₂ , the deflection voltage is not applied to the beam deflector 2 and the ion beam is moved straight to be guided to the implantation chamber 3b.
Then, at time t _3, by applying a voltage of the deflection voltage V ₃ to the beam deflector 2, introducing the ion beam incident on the time t ₃ to the implantation chamber 3c. By repeating the operations from time t ₁ to time t ₃ , the high frequency quadrupole accelerator 1
The massive ion beam emitted from the beam deflector 2
Thus, one lump-shaped ion beam is distributed to each of the ion implantation chambers 3a, 3b, 3c. In addition,
The values of the deflection voltages V ₁ and V ₃ change depending on the arrangement of the driving chamber and the beam energy.

The ion implantation chambers 3a, 3b and 3c are rotary disk type ion implantation chambers. Since each ion implantation chamber can be used for a beam power of up to about 2 kW, for example, a total of three implantation chambers can use an ion beam of up to about 6 kW for implantation. That is, with three ion implantation chambers, 1 MeV
Can be used up to 6 mA and 2 MeV up to 3 mA ion beam.

On the other hand, the high frequency quadrupole accelerator 1 of this embodiment
Applies energy corresponding to the frequency of the supplied high frequency power to the incident ion beam. When the frequency of the high-frequency power is changed, the emission period of the massive ion beam emitted by the high-frequency quadrupole accelerator 1 also changes, so the period of the deflection voltage applied to the beam deflector 2 also needs to be changed accordingly. There is. The pulse adjuster 6 controls the deflection voltage generator 5 according to the frequency and voltage of the high frequency power, and adjusts the pulse width and pulse interval of the deflection voltage output by the deflection voltage generator 5.

As a result, in the present embodiment, a plurality of ion implantation chambers are provided, and the massive ion beams emitted from the high-frequency quadrupole accelerator 1 are distributed to the plurality of ion implantation chambers. Are dispersed in the ion implantation chambers, and the sample substrates 4a, 4b, 4
Without increasing the temperature of c, 4d, 4e, 4f to 100 ° C. or higher, high energy of MeV class and large current, for example,
Ion implantation can be performed with an accelerated ion beam exceeding 2 kW. And a deep layer of the sample substrate, eg
In the case of forming a high-concentration ion-implanted layer in a layer having a depth of 1 μm or more, an increase in beam current brings about a dramatic improvement in processing ability. Ion implantation can be simultaneously performed on a plurality of sample substrates in a short time.

In this embodiment, the lumped ion beam emitted from the high frequency quadrupole accelerator 1 is distributed to each ion implantation chamber for each lump, but a plurality of continuous lumps of ion beams are collected together. You may distribute to each ion implantation chamber. However, if the number of lumps of ion beams that are collectively introduced into one ion implantation chamber is increased, the time when the ion beam is not irradiated in each ion implantation chamber becomes longer, and the time when no ion implantation is performed becomes longer. For this reason, the variation of the ion implantation becomes large in the rotation circumferential direction of the rotating disk in the ion implantation chamber.
The number of ion beam clusters capable of maintaining uniform ion implantation varies depending on the cycle of the high-frequency power supplied to the high-frequency quadrupole accelerator 1 and the rotation speed of the rotating disk. In the present embodiment, since the pulse width of the deflection voltage output by the deflection voltage generator 5 is changed by the pulse adjuster 6, the number of ion beam clusters collectively injected can be controlled. It is also possible to reduce the variation of.

In the present embodiment, the ion beam emitted from the high frequency quadrupole accelerator 1 is characterized in that it is clustered and emerges. Therefore, by distributing the ion beam to each implantation chamber, the high frequency quadrupole accelerator 1 The maximum beam extraction performance possessed by can be exhibited.

FIG. 3 is a block diagram showing a high energy ion implantation apparatus according to the second embodiment of the present invention. In addition,
The same components as those of the first embodiment are designated by the same reference numerals.

The high-energy ion implantation apparatus of this embodiment comprises a high frequency quadrupole accelerator 1, a beam deflector 2, ion implantation chambers 3a and 3b, a deflection voltage generator 5, a pulse adjuster 6, an ion source 7, and a fan-shaped magnetic field. It is composed of a mold mass separator 8 and a magnetic field lens 9.

For example, the high frequency quadrupole accelerator 1 has a high frequency quadrupole electrode having a length of about 2 m for accelerating the incident ion beam, and a high frequency voltage of 10 to 30 MHz is applied to the high frequency quadrupole electrode. To accelerate. Beam deflector 2,
Ion implantation chambers 3a, 3b, sample substrates 4a, 4b, 4
c, 4d, the deflection voltage generator 5 and the pulse adjuster 6 are the same as those in the first embodiment.

The ion source 7, the fan-shaped magnetic field type mass separator 8 and the magnetic field lens 9 convert the ion beam into a high frequency quadrupole accelerator 1.
It constitutes an ion beam injection system that is a system for making the light incident on. The ion source 7 is for generating an ion beam. The fan-shaped magnetic field type mass separator 8 separates a specific ion species required for ion implantation from the ion beam generated by the ion source 7. The magnetic field lens 9 controls the cross-sectional shape of the ion beam emitted from the fan-shaped magnetic field type mass separator 8. The ion beam whose cross-sectional shape is controlled by the magnetic field lens 9 enters the high frequency quadrupole accelerator 1.

FIG. 4 is a schematic view showing the structure of the beam deflector 2 in FIGS. 1 and 3. Inside the beam deflector 2, as shown in FIG. 4, electrodes 10a and 10b, which are two electrodes facing each other across the path of the ion beam, are provided. The electrode 10a is grounded. Electrode 10b
Is applied with a deflection voltage from the deflection voltage generator 5.

Next, the operation of the beam deflector 2 which is a characteristic operation of this embodiment will be described. FIG. 5 is a graph showing the deflection voltage applied to the electrode 10b in FIG. 4 with respect to time. At time t ₁ in FIG. 5, a deflection voltage having a predetermined voltage and a predetermined pulse width is applied to the electrode 10b. As a result, the massive ion beam incident from the high frequency quadrupole accelerator 1 by the beam deflector 2 at time t ₁ is deflected, and the ion implantation in FIG.
The ion beam is guided to the BR> insertion chamber 3a. next,
At time t ₂ , the deflection voltage is not applied to the electrode 10b. As a result, the massive ion beam incident from the high-frequency quadrupole accelerator 1 at the beam deflector _{2 at} the time t ₂ is not deflected, so that the ion implantation chamber 3 in FIG.
The ion beam is guided to b. Next, at time t ₃ , the beam deflector 2 performs the same operation as at time t ₁ .

As the beam deflector 2 repeatedly executes the operations from time t ₁ to time t ₃ , the massive ion beam emitted from the high-frequency quadrupole accelerator 1 has two ion implantation chambers 3a and 3b. It is allotted to each.

Here, the interval between time t ₁ and time t ₃ is adjusted by the pulse adjuster 6 in accordance with the frequency of the high frequency power driving the high frequency quadrupole accelerator 1. Also, at time t ₁
The pulse width of the deflection voltage at time t ₃ was set to be the time required for one massive ion beam emitted from the high-frequency quadrupole accelerator 1 to pass through the beam deflector 2. Further, the deflection electrode lengths of the electrodes 10a and 10b are set so that the other ion beam in a lump does not stay in the beam deflector 2 during the deflection of the ion beam in a lump. The deflection voltage is set accordingly.

In the case of an ion beam having an energy of 1 MeV or more, the distance between the adjacent massive ion beams is 10 to 20 cm, so that the distance between the beam deflector 2 and the ion implantation chambers 3a and 3b is sufficient. If you take
When the deflection electrode length is 10 to 20 cm, a lumpy ion beam can be distributed to each ion implantation chamber one by one with a practical deflection voltage of several tens kV.

In the present embodiment, for example, by driving the high frequency quadrupole accelerator 1 with high frequency power having a frequency of 10 to 30 MHz, the energy of the ion beam is 0.5.
It can be controlled in the range of 4 MeV. By adjusting the pulse interval and the pulse width of the deflection voltage according to the frequency, the block-shaped ion beams are sequentially introduced into the ion implantation chambers 3a and 3b one by one.

For example, the ion implantation chambers 3a and 3b are
It is possible to use one having a water-cooled rotary disk with a diameter of about 40 cm. And, the water-cooled rotary disk is about 720
The wafer was rotated at a rotation speed of [rotation / minute], a silicon wafer as a sample substrate was mounted on the surface of the water-cooled rotary disk, and the disk was mechanically scanned in the radial direction to perform uniform ion implantation. In this case, each ion implantation chamber is 2kW
The temperature of the silicon wafer is set to 1 for the beam power irradiation of
It can be maintained at about 00 ° C or lower.

According to this embodiment, phosphorus ions are implanted by an ion beam having an energy of 2 MeV and 1 mA or more. At this time, the time interval of the deflection voltage having a rectangular waveform was adjusted so that the block-shaped ion beams were distributed to the ion implantation chambers 3a and 3b one by one. as a result,
The temperature of the silicon wafers in the ion implantation chambers 3a and 3b can be kept at 100 ° C. or lower. Moreover, the result of examining the implantation uniformity of the silicon wafer in each ion implantation chamber shows that the standard deviation of the variation in the amount of ion implantation within a 6-inch diameter silicon wafer is 1% or less, which is a good level of uniform ion implantation. Showed sex. Furthermore, by ion implantation according to this embodiment, 2 MeV, 4 m
By accelerating beam irradiation up to A, the temperature of the silicon wafer in each ion implantation chamber could be maintained at 100 ° C. or lower.

[0038]

As described above, according to the present invention, since the ion beam emitted from the high frequency quadrupole accelerator is dispersed in a plurality of ion implantation chambers, it exceeds 2 kW emitted from the high frequency quadrupole accelerator. The sample substrate temperature can be maintained at about 100 ° C. or lower even for the accelerated ion beam.
With these, the maximum beam extraction performance of the high-frequency quadrupole accelerator can be exhibited and ion implantation can be performed.
It is possible to provide a high-energy ion implanter capable of implanting an accelerating beam without waste and improving the ion implant processing capability.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of a high energy ion implantation apparatus according to a first embodiment of the present invention.

2 (a) is a graph showing a current value of an ion beam incident on a beam deflector in FIG. 1 with respect to time, and FIG. 2 (b) is a deflection voltage applied to the beam deflector in FIG. It is a graph which shows the value with respect to the passage of time.

FIG. 3 is a block diagram showing a high energy ion implantation apparatus according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing the structure of the beam deflector in FIG. 1 or FIG.

5 is a graph showing a value of a deflection voltage applied to an electrode 10b in FIG. 4 with respect to time.

[Explanation of symbols]

 1 high-frequency quadrupole accelerator 2 beam deflector 3a, 3b, 3c ion implantation chamber 4a, 4b, 4c, 4d, 4e, 4f sample substrate 5 deflection voltage generator 6 pulse adjuster 7 ion source 8 fan-shaped magnetic mass separator 9 Magnetic field lens 10a, 10b Deflection electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01J 37/08 H01L 21/265

Claims (5)

[Claims] 1. A high-frequency quadrupole accelerator which has four electrodes having a corrugated shape along the axial direction and introduces an ion beam into the central portion of the positions of these four electrodes to accelerate the ion beam. An ion beam injection system for introducing an ion beam into the high frequency quadrupole accelerator, a beam deflector for deflecting the ion beam emitted from the high frequency quadrupole accelerator, and an ion beam passing through the beam deflector A high-energy ion implantation apparatus having a plurality of ion implantation chambers for ion implantation using
Pulse width and repetition of deflection voltage for controlling beam deflector
A pulse adjuster that changes the
The rectifier is a high-frequency high-voltage generator that drives the high-frequency quadrupole accelerator.
Pulse width and repetition of the deflection voltage according to the pressure cycle
A high-energy ion implanter characterized by changing the period . 2. Four of the corrugated shapes are formed along the axial direction.
It has an electrode and an ion beam is placed at the center of these four electrode positions.
High-frequency quadruple that introduces a beam to accelerate the ion beam
Ion beam to the polar accelerator and this high-frequency quadrupole accelerator
An ion beam injection system for introducing the high frequency quadruple
Beam that deflects the ion beam emitted from the polar accelerator
The deflector and the ion beam that passed through this beam deflector
Multiple ion implantation chambers for ion implantation using
In a high energy ion implanter having
Pulse width and repetition of deflection voltage for controlling beam deflector
A pulse adjuster that changes the
The rectifier is a high-frequency high-voltage generator that drives the high-frequency quadrupole accelerator.
Pulse width and repetition of the deflection voltage according to the pressure cycle
By changing the period, the beam deflector is
Deflection the ion beam accelerated by the polar accelerator in multiple directions
Then , the high-energy ion implantation apparatus is characterized in that it is distributed to the plurality of ion implantation chambers . 3. Four pieces having a corrugated shape along the axial direction
It has an electrode and an ion beam is placed at the center of these four electrode positions.
High-frequency quadruple that introduces a beam to accelerate the ion beam
Ion beam to the polar accelerator and this high-frequency quadrupole accelerator
An ion beam injection system for introducing the high frequency quadruple
Beam that deflects the ion beam emitted from the polar accelerator
The deflector and the ion beam that passed through this beam deflector
Multiple ion implantation chambers for ion implantation using
In high-energy ion striking Chikomi device having, before
Pulse width and repetition of deflection voltage for controlling beam deflector
A pulse adjuster that changes the
The rectifier is a high-frequency high-voltage generator that drives the high-frequency quadrupole accelerator.
Pulse width and repetition of the deflection voltage according to the voltage value of the pressure.
A high-energy ion implanter characterized by changing the cycle . 4. Four of the corrugated shapes are formed along the axial direction.
It has an electrode and an ion beam is placed at the center of these four electrode positions.
High-frequency quadruple that introduces a beam to accelerate the ion beam
Ion beam to the polar accelerator and this high-frequency quadrupole accelerator
An ion beam injection system for introducing the high frequency quadruple
Beam that deflects the ion beam emitted from the polar accelerator
The deflector and the ion beam that passed through this beam deflector
Multiple ion implantation chambers for ion implantation using
In a high energy ion implanter having
Pulse width and repetition of deflection voltage for controlling beam deflector
A pulse adjuster that changes the
The rectifier is a high-frequency high-voltage generator that drives the high-frequency quadrupole accelerator
Pulse width and repetition of the deflection voltage according to the voltage value of the pressure.
The beam deflector changes the
The ion beam accelerated by the quadrupole accelerator is polarized in multiple directions.
A high-energy ion implantation device, characterized in that it is distributed to the plurality of ion implantation chambers . 5. The four wavy shapes along the axial direction
It has an electrode and an ion beam is placed at the center of these four electrode positions.
High-frequency quadruple that introduces a beam to accelerate the ion beam
Ion beam to the polar accelerator and this high-frequency quadrupole accelerator
An ion beam injection system for introducing the high frequency quadruple
Beam that deflects the ion beam emitted from the polar accelerator
The deflector and the ion beam that passed through this beam deflector
Multiple ion implantation chambers for ion implantation using
In a high-energy ion implanter with
Pulse width and repetition rate of deflection voltage to control the arm deflector
A pulse regulator that changes the period is provided.
Is a block (vane emitted from the high-frequency quadrupole accelerator).
(Ching beam)
The pulse signal to be introduced into the on-implantation room is output to the beam deflector.
Force to simultaneously perform ion implantation in the plurality of ion implantation chambers.
A high-energy ion implanter, which is characterized in that it is subjected to implantation processing.