JP3403383B2 - Ion source control method and ion source control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention produces a plasma by ionizing an ion species gas in a high vacuum in order to perform processes such as ion beam sputtering, ion beam cleaning, and film formation assist of oxides and nitrides. The present invention relates to an ion source control method and an ion source control device used for controlling an ion beam so that an ion beam is not sputtered in an ion source main body in an ion source that takes out ions from the plasma and causes the ions to converge and flow out.

[0002]

2. Description of the Related Art Conventionally, as an example of the above-mentioned ion source, ionization of ion species gas is performed in a plasma generating chamber to generate plasma, and ions are focused from the plasma by using an extraction electrode and an acceleration electrode. There is known a configuration in which it is caused to flow into the processing chamber.

As another example of the above-mentioned ion source, by using a focusing electrode and an extracting electrode, a focusing electrode and an accelerating electrode to generate plasma by ionizing ion species gas in a plasma generating chamber. A configuration is known in which ions are focused from the plasma and flow out into the processing chamber.

[0004]

By the way, along with the miniaturization of semiconductors and the miniaturization and high density of semiconductors and the like, there has been a demand for higher purification of ion beams used for manufacturing them. However, in the conventional ion source as described above, as a result of analyzing the ion trajectories, ions having a positive potential are negative depending on the balance of the potential applied to each electrode and the generation condition of the plasma generated in the plasma generation chamber. Impurities are generated by sputtering on the extracting electrode and the accelerating electrode having the potential. Therefore, as described above, it cannot be applied to the use where high purity of the ion beam is required.

An object of the present invention is to solve the above-mentioned conventional problems, in which ions are converged and extracted from the plasma generated in the plasma generation chamber by the focusing electrode and the extracting electrode, While focusing the ions with the focusing electrode and the accelerating electrode, and preventing the ion beam from spattering the extraction electrode and the accelerating electrode to generate impurities when the ion beam profile is controlled to flow out by acceleration. Therefore, an object of the present invention is to provide an ion source control method and an ion source control device capable of generating and supplying a high-purity ion beam.

[0006]

In order to solve the above-mentioned problems, an ion source control method of the present invention is designed such that ions are converged and extracted from a plasma generated in a plasma generation chamber by a focusing electrode and an extracting electrode. While focusing the ion beam by the focusing electrode and the accelerating electrode, when controlling the beam profile of the ions for accelerated outflow, the presence or absence of sputtering of the ion beam for the extraction electrode is detected, and when sputtering is detected, The ion beam is controlled to suppress the divergence of the ion beam in order to prevent the ion beam from being sputtered on the extraction electrode, and the presence or absence of sputtering of the ion beam on the acceleration electrode is detected. Sputter phosphorus for the acceleration electrode of The thereby controlling so as to suppress dispersion of the ion beam to prevent.

In the ion source control method, the inflow current value to the extraction electrode and the acceleration electrode is monitored,
The extraction electrode by detecting whether or not there is inflow of charged particles of a specified value or more, the presence or absence of sputtering of the ion beam to the acceleration electrode, or the extraction electrode in the ion beam, from the acceleration electrode It is possible to irradiate the ion beam with light of a specific wavelength at the outflow portion and detect the presence or absence of sputtering of the ion beam with respect to the extraction electrode and the acceleration electrode from the amount of light.

In the ion source control method, the extraction electrode section is controlled by at least one of voltage control of the focusing electrode and voltage control of the extraction electrode adjacent to the extraction electrode. The divergence of the ion beam with respect to the extraction electrode is suppressed, and in the acceleration electrode section, the voltage is controlled by at least one of the voltage control of the focusing electrode adjacent to the acceleration electrode and the voltage control of the acceleration electrode. It is possible to control so as to suppress the divergence of the ion beam with respect to the accelerating electrode, or to control the voltage of each electrode as described above, and in the plasma generation chamber, the gas that becomes an ion species in the process of generating plasma is generated. To control ion beam divergence by adjusting the supply flow rate, power supply power for plasma generation, or plasma generation chamber pressure. It is possible to control.

In order to solve the above-mentioned problems, the ion source control apparatus of the present invention generates plasma by the plasma generation means in the plasma generation chamber, and then the ions are converged and extracted from the plasma by the focusing electrode and the extracting electrode. In the ion source for focusing the ion beam by the focusing electrode and the accelerating electrode, and controlling the beam profile of the ions for accelerated outflow, the presence or absence of the sputtering of the ion beam for the extraction electrode and the acceleration electrode is checked. Detecting means for detecting, and detecting the sputtering by this detecting means, the extraction electrode of the ion beam, a control means for controlling so as to suppress the divergence of the ion beam to prevent sputtering of the acceleration electrode. Be prepared.

In the ion source controller, an inflow current detector for monitoring the inflow current value to the extraction electrode or the acceleration electrode can be used as the detection means, or the detection means can be the extraction current An electrode, a light source for irradiating the ion beam flowing out from the accelerating electrode with light of a specific wavelength, and an impurity generated by sputtering the ion beam with respect to the extraction electrode, the accelerating electrode from the amount of light irradiated on the ion beam And a scattered light detector for detecting scattered light from.

In the ion source control device, as the control means, in the extraction electrode portion, at least a voltage applied to the focusing electrode adjacent to the extraction electrode and a voltage applied to the extraction electrode. In the acceleration electrode section, at least one of a voltage applied to the focusing electrode adjacent to the acceleration electrode and a voltage applied to the acceleration electrode is adjusted. Or as the control means, in addition to the control of the voltage applied to each electrode as described above,
It can be configured to adjust any one of the supply flow rate of the gas to be the ion species in the plasma generation means, the power supply power for plasma generation, and the plasma generation chamber pressure.

According to the present invention as described above, ions are converged and extracted from the plasma generated in the plasma generation chamber by the focusing electrode and the extracting electrode, and the ion beam is converged by the focusing electrode and the accelerating electrode. In addition, when controlling the beam profile of the ions for accelerated outflow, it is necessary to detect the presence or absence of sputtering on the extraction electrode of the ion beam and the acceleration electrode, and to control the ion beam divergence when sputtering is detected. Therefore, it is possible to prevent the generation of impurities by preventing the sputtering for the extraction electrode and the acceleration electrode.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described. FIG. 1 is an overall configuration diagram showing the ion source control apparatus according to the first embodiment of the present invention applied to an ion source, with an ion source body cut away.

The present embodiment shows an example applied to an ion source main body with a built-in electrode. As shown in FIG. 1, the ion source body 1 is composed of a plasma generation chamber 2 and an ion beam outflow portion 3. Ion beam outflow section 3
Is a processing chamber 4 for performing various processes using the ion beam such as ion beam sputtering and ion beam cleaning.
Are linked to.

Explaining the plasma generation chamber 2, one side of the housing 10 is open. One end of a vacuum exhaust pipe 12 is connected to the peripheral wall 11 of the housing 10 at a position close to the open portion side, and the other end of the vacuum exhaust pipe 12 is a vacuum exhaust pressure control device 13
Are linked to. As the vacuum exhaust pressure control device 13,
Basically, it is composed of a pressure control valve and a turbo molecular pump for vacuum evacuation (for ultra-high vacuum) in the subsequent stage, and through the vacuum exhaust pipe 12 by opening / closing control of the pressure control valve and driving of the turbo molecular pump. It is designed to exhaust. A gas supply pipe 15 is provided on the end wall 14 on the side opposite to the open portion of the housing 10.
Is connected to one end, and the other end of the gas supply pipe 15 is connected to the ion species gas flow rate control device 16. The ion species gas flow rate control device 16 basically includes a pressure gauge and a gas valve, and the ion species gas supply source (not shown) controls the opening and closing of the gas valve to supply the ion species gas to the housing 10.
Can be supplied within. Argon gas is generally used as the ion species gas. The ion species gas flow rate control device 16 is used as a pair with the evacuation pressure control device 13.

The microwave antenna 1 is provided inside the end wall 14.
7 is provided, and the supporting portion 18 of the microwave antenna 17 is inserted through the end wall 14. The electrode 1 is provided inside the peripheral wall 11.
9 is provided. Microwave antenna 17 and electrode 1
9 is connected to a power source 20 for plasma generation. An electron resonance (ECR) high-frequency generator is used as the plasma generation power source 20. Then, by supplying power from the plasma generation power source 20 to the microwave antenna 17 and the electrode 19 to introduce an electromagnetic wave from the microwave antenna 17 and discharging between the microwave antenna 17 and the electrode 19, the inside of the housing 10 is discharged. Plasma in which ions and electrons are mixed can be generated from the argon gas supplied to the. A magnet 21 is provided on the outer side of the peripheral wall 11 so that the generated plasma can be concentrated in the central portion of the housing 10.

Explaining the ion beam outflow portion 3, a housing 22 communicating with the open side of the housing 10 is integrally provided, and the housing 22 is formed to have a slightly larger outer shape than the housing 10. An open portion of the housing 22 on the side opposite to the housing 10 communicates with the processing chamber 4. In the housing 22, there are sequentially spaced from the ion generation chamber 2 side, and in a state of being electrically insulated from each other, the focusing electrode 23, the extraction electrode 24,
Focusing electrode 25, accelerating electrode 26 and focusing electrode 27
Is provided. Focusing electrode 23, extraction electrode 24,
Focusing electrode 25, accelerating electrode 26 and focusing electrode 27
The windows 28, 29, 30, 31, and 32 that form the ion passages are formed therein. The windows 31 and 32 of the acceleration electrode 26 and the focusing electrode 27 are formed in a tapered shape that gradually expands toward the processing chamber 4 side.

The focusing electrode 23 is a DC high voltage stabilizing power source 33.
The extraction electrode 24 is connected to the DC high voltage stabilizing power source 35 via the inflow current detector 34, and the focusing electrode 2
5 is connected to the DC high voltage stabilizing power supply 36, and is connected to the acceleration electrode 2
6 is a DC high voltage stabilizing power source 3 via an inflow current detector 37
8 and the converging power supply 27 is a DC high voltage stabilizing power supply 3
9 is connected. A desired potential is applied to each of the electrodes 23 to 27 by each of the power supplies 33, 35, 36, 38 and 39. Then, ions are converged and extracted from the plasma generated in the plasma generation chamber 2 by the focusing electrode 23 and the extracting electrode 24, and the focusing electrode 25, the accelerating electrode 26,
Ions can be focused by the focusing electrode 27, and the beam profile of the ions can be controlled to be accelerated outflow into the processing chamber 4. The inflow current detectors 34 and 37 basically have a resistance having a large resistance value so that a minute current can be measured with high accuracy.
It is composed of a precision voltage measuring circuit that accurately measures the voltage generated at both ends. Then, when the extracted ion beam sputters the extraction electrode 24 and the acceleration electrode 26, a minute ion current can be detected, and the plasma in the plasma generation chamber 2 causes the electrode 19 or the like to be damaged by some reason. The inflow charge of dust particles generated during sputtering can be instantly detected, and the time constant is set to be less than microsecond. The detection results of the inflow current detectors 34 and 37 are sent to the overall control unit 40.

The integrated control unit 40 is composed of a computer,
Vacuum exhaust pressure control device 13, ion species gas flow rate control device 16, plasma generation power source 20, DC high voltage stabilizing power source 3
3, 35, 36, 38, 39 can be controlled. A sputtering avoidance program is incorporated in the integrated control unit 40 in advance, and ion beam sputtering for the extraction electrode 24 and the acceleration electrode 26 is detected based on the detection data sent from the inflow current detectors 34 and 37. DC high voltage stabilized power supply 3
By controlling either or both of 3, 35 and by controlling any or all of the DC high voltage stabilizing power sources 36, 38, 39, the diffusion of the ion beam at the extraction electrode 24 and the acceleration electrode 26 is prevented. It can be suppressed.

Next, the ion source control method according to the present embodiment will be explained. First, as described above, by driving the vacuum exhaust pressure control device 13, the plasma generation chamber 2, the ion beam outflow portion 3 and the processing chamber 4 are, for example, 1 × 10 ⁻⁴ To
Evacuate to a high vacuum below rr. The processing chamber 4 has a higher vacuum,
For example, the gas may be evacuated to 1 × 10 ⁻⁵ Torr or less. Further, the focusing electrodes 23 are positive potentials, for example, +2 kV, and the extraction electrodes 24 are negative potentials, for example, −2 kV, and the focusing electrodes 2 by the power sources 33, 35, 36, 38, and 39.
5 is a positive potential, for example, +2.5 kV, the acceleration electrode 26
Is a negative potential or installation potential, for example, −0.5 kV or 0 V, and the focusing electrode 27 is a positive potential, for example, +2.5.
The potential is applied so that the potential becomes kV.

Next, the plasma generating power source 20 supplies power to the microwave antenna 17 to introduce electromagnetic waves,
Power is supplied to the electrode 19 and the ion species gas flow rate controller 16 is driven to supply argon gas from the ion supply source to the argon generation chamber 2 through the gas supply pipe 15. Accordingly, the microwave antenna 17 and the electrode 19
The argon gas is ionized by the discharge during the period, and a plasma having a potential of 0 can be generated in a mixed state of ions and electrons. The generated plasma is concentrated by the magnet 21 in the central portion of the plasma generation chamber 2.

In the ion beam outflow portion 3, the focusing electrode 23 has the same positive potential as the ions extracted from the plasma, and the extraction electrode 24 has the negative potential opposite to the ions.
Due to the influence of the extraction electrode 24 (potential gradient), ions can be selectively extracted from the plasma in the plasma generation chamber 2 and the electrons can be returned to the repulsive force. When the ions are extracted, the ions can be extracted into the window 28 of the extraction electrode 24 through the window 28 of the extraction electrode 24 by bundling the ions into a beam shape by the binding force of the potential without causing sputtering. Since the subsequent focusing electrode 25 has the same positive potential as the ions and the accelerating electrode 26 has the negative potential opposite to the ions or the installation potential (0 potential), it is extracted from the window 29 of the extraction electrode 24 as described above. The generated ion beam is passed through the window 30 of the focusing electrode 25 by binding the ions into a beam shape by the restraining force by the potential without causing sputtering, and the energy lost by the focusing of the ion beam is replenished by the accelerating electrode 26. It can be passed through the window 31 in an accelerated state. This accelerated ion beam can pass through the window 32 of the focusing electrode 27, which has the same positive potential as that of the accelerated ion beam, in a converged state and flow out into the processing chamber 4.

Although the ion beam is in a divergent state by being accelerated, the window 31 of the acceleration electrode 26 and the focusing electrode 2
Since the window 32 of 7 has a tapered shape that gradually expands toward the outflow side, the ion beam is prevented from being sputtered on the wall surface when passing through the windows 31 and 32.
Can be prevented. Then, the focusing electrodes 25 and 27
Since the ion beam uniformly stabilizes the acceleration of the ion beam, it is possible to prevent the sputtering of the ion beam on the acceleration electrode 26 and control the beam profile (the relationship between the beam diameter and the density). That is, by decreasing the voltage applied to the focusing electrodes 25 and 27, the beam diameter can be expanded and the ion density can be reduced, and by increasing the voltage applied to the focusing electrodes 25 and 27, the beam diameter can be reduced. It can be reduced to increase the ion density.

In order to flow out a high-purity ion beam into the processing chamber 4, first, the extraction electrode 24, which easily attracts the ion beam at a negative potential opposite to that of the ion beam, the potential opposite to that of the ion beam, or the installation potential. Therefore, it is necessary that the ion beam is not sputtered (does not flow into) the acceleration electrode 26 that easily attracts the ion beam. In this case, if the focusing power of the ion beam by the focusing electrode 23 is insufficient and the beam diameter is expanded, and the ion beam extraction electrode 24 is sputtered, the impurities generated by this sputtering enter the ion beam. Since it is included, an inflowing ion current flows to the side of the DC high voltage stabilizing power supply 35. This inflowing ionic current can be detected by the inflowing current detector 34 inserted between the extraction electrode 24 and the DC high voltage stabilizing power supply 35, and the inflowing current detector 34 detects this detection data by the integrated control unit 40. Send to. Based on the detection data sent out, the overall control unit 40 controls the DC high voltage stabilizing power supply 33 according to a pre-installed sputtering avoidance (purity maintenance) program to raise the voltage of the focusing electrode 23 and repel the ion beam. To reduce the beam diameter and suppress ion beam divergence. If the sputtering of the extraction electrode 24 by the ion beam is still not solved by this, the DC high voltage stabilizing power supply 35 is controlled to reduce the acceleration voltage applied to the extraction electrode 24 to weaken the attraction force of the ion beam. Suppress ion beam divergence. Alternatively, both of them are controlled to suppress ion beam divergence. As a result, it is possible to prevent the ion beam from being sputtered on the extraction electrode 24 and prevent impurities from being generated and mixed into the ion beam.

Further, in the unlikely event that the focusing force of the ion beam by the focusing electrode 25 is insufficient, the ion beam accelerating electrode 2
When the sputtering for 6 occurs, the impurities generated by this sputtering are included in the ion beam. Therefore, the inflowing ion current is inserted between the accelerating electrode 26 and the DC high-voltage stabilizing power supply 38 as described above. It is detected by the inflow current detector 37, and the inflow current detector 37 sends this detection data to the integrated control unit 40. Integrated control unit 40
Similarly to the above, based on the sent detection data, the DC high-voltage stabilizing power supplies 36 and 39 are controlled according to a pre-installed sputtering avoidance program to increase the voltage of the focusing electrodes 25 and 27, and It strengthens the repulsive force and reduces the beam diameter, suppressing the divergence of the ion beam. This also enables the electrode 26 for acceleration by the ion beam.
If the sputtering is not solved, the DC high voltage stabilizing power supply 38 is controlled to reduce the acceleration voltage applied to the acceleration electrode 26, weaken the ion beam attraction force, and suppress the ion beam divergence. Alternatively, both of them are controlled to suppress ion beam divergence. As a result, it is possible to prevent the ion beam from being sputtered on the accelerating electrode 26 and prevent impurities from being generated and mixed into the ion beam. Therefore, a high-purity ion beam can be made to flow into the processing chamber 4.

Next, a second embodiment of the present invention will be described. FIG. 2 is an overall configuration diagram showing the ion source control apparatus according to the second embodiment of the present invention applied to an ion source, with the ion source main body cut away.

The present embodiment is different from the first embodiment in the detection means for ion beam sputtering with respect to the extraction electrode 24 and the acceleration electrode 26, and other configurations are the same, so the same parts are used. Are denoted by the same reference numerals and the description thereof will be omitted, and different configurations will be mainly described.

In the present embodiment, as shown in FIG. 2, in the vicinity of the ion beam outflow side of the extraction electrode 24 and the acceleration electrode 26, light of a specific wavelength is transmitted to the housing 22 in a direction perpendicular to the ion beam outflow direction. Light source 4 for emitting light
1 and 42 are provided, the light emitted from each of the light sources 41 and 42 through the transmission windows 43 and 44 formed in the housing 22 and transmitted through the ion beam is detected to detect the presence or absence of scattered light, and the detection data is obtained. Scattered light detectors 45 and 46 for sending to the integrated control unit 40 are provided. A semiconductor laser or the like can be used as the light sources 41 and 42.
42 emits light of a single frequency. Scattered light detector 45,
As 46, a filter that allows only the light of a specific wavelength emitted from the light sources 41 and 42 to pass therethrough and a photomultiplier tube that is arranged in the subsequent stage can be configured. Then, the light source 41,
When the ion beam does not contain impurities, the light emitted from 42 is transmitted through the ion beam and is absorbed by the light absorbing portion at the opposite position, and the scattered light detectors 45 and 46 contain the impurities. In the case where impurities are contained in the ion beam, the impurities cannot be detected.
Since the light path from 2 is blocked, the scattered light detector 4
5, 46, it is possible to detect extremely strong scattered light.

Next, the ion source control method according to the present embodiment will be explained. An ion beam can be made to flow from the ion source main body into the processing chamber 4 in the same manner as in the first embodiment. If the focusing power of the ion beam by the focusing electrode 23 is insufficient and sputtering of the ion beam extracting electrode 24 occurs, impurities generated by this sputtering are contained in the ion beam. The light emitted from is blocked by impurities and can be detected by the scattered light detector 45, and the scattered light detector 45 collects this detection data.
Send to 0. Based on the detection data sent out, the overall control unit 40 controls the DC high voltage stabilizing power supply 33 according to a pre-installed sputtering avoidance (purity maintenance) program to raise the voltage of the focusing electrode 23 and repel the ion beam. Strengthens the force to reduce the beam diameter and suppress ion beam divergence. If the sputtering of the extraction electrode 24 by the ion beam is still not solved by this, the DC high voltage stabilizing power supply 35 is controlled to reduce the acceleration voltage applied to the extraction electrode 24 to weaken the attraction force of the ion beam. Suppress the divergence of the ion beam. Alternatively, both of them are controlled to suppress ion beam divergence.
As a result, it is possible to prevent the ion beam from being sputtered on the extraction electrode 24 and prevent impurities from being generated and mixed into the ion beam.

In the unlikely event that the focusing power of the ion beam by the focusing electrode 25 is insufficient, the ion beam accelerating electrode 2
When the sputtering for 6 is generated, the impurities generated by this sputtering are included in the ion beam, so that the light emitted from the light source 42 is blocked by the impurities and detected by the scattered light detector 46 in the same manner as described above. Then
The scattered light detector 46 sends this detection data to the overall control unit 40. Similarly to the above, the overall control unit 40 controls the DC high voltage stabilizing power supplies 36 and 39 according to the sputtering avoidance program that is incorporated in advance based on the detection data that has been sent out, and raises the voltage of the focusing electrodes 25 and 26. , Strengthen the repulsive force of the ion beam and reduce the beam diameter,
Suppress ion beam divergence. If the sputtering of the acceleration electrode 26 by the ion beam is still not solved by this, the DC high voltage stabilizing power supply 38 is controlled to lower the acceleration voltage applied to the acceleration electrode 26 to weaken the attraction force of the ion beam. Suppress the divergence of the ion beam. Alternatively, both of them are controlled to suppress ion beam divergence. As a result, the ion beam acceleration electrode 2
It is possible to prevent sputtering of No. 6 and prevent generation and mixing of impurities into the ion beam. Therefore, a high-purity ion beam can be made to flow into the processing chamber 4.

Although each of the above embodiments has been described as applied to an ion source main body with a built-in electrode, it can also be applied to an ion source main body with an external electrode attached, as shown in FIG. The structure of the mounting type will be briefly described.

As shown in FIG. 3, the plasma generation chamber 2 includes the housing 10, the vacuum exhaust pipe 12, and the gas control pipe 1 as described above.
5, microwave antenna 17, electrode 19, magnet 21 and the like. In the ion beam outflow section 3,
The housing 22 is configured to be short, and the focusing electrode 23 is provided inside the housing 22.
The extraction electrode 24 and the focusing electrode 25 are provided, and the housing 22
The acceleration electrode 26 is provided in the open portion on the side opposite to the housing 11 in
And the converging electrodes 27 are sequentially attached at desired intervals by cylindrical connecting members 47 and 48 made of an insulating material and arranged at a plurality of positions on the circumference. Although the ion source control device according to the first embodiment is applied in FIG. 3, the ion source control device according to the second embodiment may be applied.

As a third embodiment of the present invention, in addition to the control so as to suppress the divergence of the ion beam on the side of the ion beam outflow portion 3 as in the first and second embodiments,
If necessary, the overall control unit 40 sets the plasma generation conditions in the plasma generation chamber 2 in accordance with a sputtering avoidance (purity maintenance) program according to a vacuum exhaust pressure control device 13, an ion species gas flow rate control device 16, and a microwave antenna 1.
7, power source 20 for plasma generation for supplying power to electrode 19
To control the pressure in the plasma generation chamber 2, the supply gas flow rate,
It can be adjusted to reduce at least one of the power-up powers. Thereby, the divergence of the ion beam in the first and second embodiments can be further suppressed.

The present invention is not limited to the first and second embodiments. For example, the focusing electrodes 25 and 27 for focusing the beam and controlling the profile of the beam to accelerate and flow out. As for the acceleration electrode 26, an acceleration electrode, a focusing electrode, and
You may arrange in order of the acceleration electrode. Also, the focusing electrode 2
By lowering the voltage applied to 3, 25 and 27, the beam diameter is expanded to increase the ion density, and the focusing electrode 2
By increasing the voltage applied to 3, 25 and 27, the beam diameter can be reduced and the ion density can be increased. However, when the beam cross-sectional shape is changed from a circular shape to an elliptic diameter shape, each electrode 23 It suffices to selectively control the voltages of ~ 27. Further, the focusing electrode adjacent to the accelerating electrode is divided into a plurality of pieces in the circumferential direction, and the beam profile can be easily controlled by controlling the voltage applied to each divided piece. In addition to the above, the present invention can be modified in various ways without departing from the basic technical idea thereof.

[0035]

As described above, according to the present invention, ions are converged and extracted from the plasma generated in the plasma generation chamber by the focusing electrode and the extracting electrode, and this ion beam is used for the focusing electrode and the accelerating electrode. While focusing by the electrode and controlling the ion beam profile for accelerated outflow, the presence or absence of sputtering for the ion beam extraction electrode and the acceleration electrode is detected, and when the sputtering is detected, the divergence of the ion beam is suppressed. By controlling, it is possible to prevent the sputtering for the extraction electrode and the acceleration electrode and prevent the generation of impurities. Therefore, a high-purity ion beam can be generated and supplied.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram in which an ion source control device according to a first embodiment of the present invention is applied to an ion source and an ion source main body is cut away.

FIG. 2 is an overall configuration diagram in which an ion source control device according to a second embodiment of the present invention is applied to an ion source and an ion source main body is cut away.

FIG. 3 is an overall configuration diagram in which the ion source control device according to the first embodiment of the present invention is applied to an ion source of another example and an ion source body is cut away.

[Explanation of symbols]

1 Ion source body 2 Plasma generation chamber 3 Ion beam outflow section 4 processing room 12 Vacuum exhaust pipe 15 gas supply pipe 17 Microwave antenna 19 electrodes 21 magnet 23 Focusing electrode 24 Extraction electrode 25 Focusing electrode 26 Accelerating electrodes 27 Focusing electrode 28-32 windows 41, 42 light source

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 63-289751 (JP, A) JP 5-225935 (JP, A) JP 7-307140 (JP, A) JP 2000-294158 (JP, A) JP 2000-199738 (JP, A) JP 6-150861 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 27/02 H01J 27/16 H01J 37/08

Claims (10)

(57) [Claims] 1. A method for extracting an ion beam from plasma
Plasma generation that generates plasma in the outflow direction
Chamber, focusing power for pre-focusing the extracted ion beam
Pole, for extracting the ion beam from the plasma chamber
Electrodes, refocusing the extracted ion beam
Focusing electrode, predetermined acceleration for refocused ion beam
Accelerating electrode for applying energy, accelerating divergence
It consists of focusing electrodes for refocusing the ion beam.
In the ion source, the extraction in advance focus ions by the focusing electrode and the leading electrode from the generated plasma in the plasma generating chamber, convergence accelerated ion beam by the focusing electrode and the accelerating electrode In addition to controlling the beam profile of the ions to flow out, the presence or absence of sputtering of the ion beam with respect to the extraction electrode is detected, and if sputtering is detected, sputtering of the ion beam with respect to the extraction electrode is performed. In order to prevent the above, the ion beam divergence is controlled to be suppressed, and the presence or absence of sputtering of the ion beam on the acceleration electrode is detected. When sputtering is detected, the ion beam is prevented from sputtering on the acceleration electrode. In order to Ion source control method for controlling so as to suppress divergence of beam. 2. An ion beam sputtering for the extraction electrode and the acceleration electrode is performed by monitoring the inflow current value to the extraction electrode and the acceleration electrode, and checking whether or not the inflow of charged particles exceeds a specified value. The ion source control method according to claim 1, wherein the presence or absence is detected. 3. The ion beam is irradiated with light of a specific wavelength at the outflow portion from the extraction electrode and the acceleration electrode in the ion beam, and the ion beam is irradiated by the extraction electrode and the acceleration electrode.
Composed of electrode material generated by sputtering the electrode
2. The ion source control method according to claim 1, wherein the presence or absence of ion beam sputtering on the extraction electrode and the acceleration electrode is detected from the amount of scattered light by the fine particles . 4. In the extraction electrode part, the divergence of an ion beam to the extraction electrode is suppressed by controlling at least one of the voltage control of the focusing electrode adjacent to the extraction electrode and the voltage control of the extraction electrode, In the accelerating electrode section, control is performed so as to suppress divergence of an ion beam to the accelerating electrode by controlling at least one of voltage control of a focusing electrode adjacent to the accelerating electrode and voltage control of the accelerating electrode. 4. The ion source control method according to any one of 1 to 3. 5. The voltage of each electrode is controlled, and at least one of the supply flow rate of gas that becomes an ion species in the process of generating plasma in the plasma generation chamber, the power supply power for plasma generation, and the pressure in the plasma generation chamber. The ion source control method according to claim 4, wherein the ion beam is controlled so as to suppress the divergence of the ion beam. 6. In the plasma generation chamber, plasma is generated by the plasma generation means, ions are focused and extracted from the plasma by the focusing electrode and the quoting electrode, and the ion beam is focused by the focusing electrode and the accelerating electrode. In the ion source for controlling and accelerating outflow of the beam profile of the ions, the extraction electrode of the ion beam, detection means for detecting the presence or absence of sputtering of the acceleration electrode, and when detecting the sputtering by this detection means An ion source control device comprising: a control unit that controls to suppress the divergence of the ion beam in order to prevent sputtering of the ion beam onto the extraction electrode and the acceleration electrode. 7. The ion source control device according to claim 6, wherein the detection means is an inflow current detector for monitoring inflow current values with respect to the extraction electrode and the acceleration electrode. 8. A light source for irradiating the ion beam flowing out from the extraction electrode and the acceleration electrode with light of a specific wavelength, and a detection means for the extraction electrode and the acceleration electrode based on the amount of light irradiated on the ion beam. 7. The ion source control device according to claim 6, further comprising a scattered light detector that detects scattered light from impurities generated by sputtering of the ion beam. 9. The acceleration means is configured to adjust at least one of a voltage applied to a converging electrode adjacent to the extraction electrode and a voltage applied to the extraction electrode in the extraction electrode section for acceleration. 9. The electrode part for use according to claim 6, wherein at least one of a voltage applied to a focusing electrode adjacent to the acceleration electrode and a voltage applied to the acceleration electrode is adjusted. Ion source controller. 10. The control means, in addition to controlling the voltage applied to each electrode, at least one of the supply flow rate of a gas serving as an ion species in the plasma generation means, a power supply power for plasma generation, and a plasma generation chamber pressure. 10. The ion source control device of claim 9 configured to adjust the.