JP2000048999A - Inspection for high-frequency power source and pressure guage in plasma processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspecting method for a high-frequency power source and an inspecting method for a pressure guage to allow easy and quick inspection for the power source and the pressure guage in high-frequency plasma processing. SOLUTION: This plasma processing is a type of processing to generate high-frequency plasma in a vacuum chamber and to control an oscillation frequency of a high-frequency power source 2 so as to make load impedance minimum. In an inspecting method for the power source 2, an output of the power source 2 and its oscillation frequency are detected and compared with their relating data in a proper condition preliminarily stored to determine its quality. In an inspecting method for a pressure guage 9, a degree of vacuum of the vacuum chamber and the oscillation frequency of the power source 2 are detected and compared with their relating data in a proper condition preliminarily stored to determine its quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a high-frequency power supply and a pressure gauge in plasma processing, and more particularly, to a plasma processing for processing a substrate or the like by high-frequency plasma more easily and quickly. The present invention relates to a high-frequency power supply capable of inspecting a power supply and a pressure gauge and a method of inspecting a pressure gauge.

[0002]

2. Description of the Related Art Plasma processing is a process in which a semiconductor substrate or the like is etched or ashed by plasma generated in a plasma processing apparatus. The plasma processing apparatus used for such processing includes a vacuum chamber (reaction vessel) in which a predetermined degree of vacuum is maintained and a material gas is supplied in a constant amount, and a metal cylinder as an internal electrode or an etch tunnel in the vacuum chamber. Mainly composed of
By applying high-frequency power to the metal cylinder, plasma is excited in the vacuum chamber (Japanese Unexamined Patent Publication (Kokai) No. 3-32).
2501, JP-A-6-168896).

A conventional plasma processing apparatus includes a matching device (frequency matching circuit) for responding to a change in impedance during plasma generation in a plasma generation circuit (plasma source) on the vacuum chamber side and improving power transfer efficiency. ) Is attached. The matching device is configured by an LC circuit including a variable capacitor, and is a device for matching the impedance of the plasma source to the power supply side.

However, since the matching device adjusts the load impedance by driving the variable capacitor, the response speed is actually slow, and perfect matching of the impedance with respect to the power supply is not obtained. As a result, there is a problem that a sufficient power transfer efficiency cannot be obtained, and further, in the plasma processing apparatus, stable plasma may not be maintained due to a difference from a frequency on a power supply side.

[0005] Therefore, the present inventors, when supplying high-frequency power to the plasma processing apparatus, match the oscillation frequency on the power supply side in accordance with the change in load impedance.
It has been found that the power transfer efficiency can be maximized and more stable plasma can be obtained, and a patent application has already been filed as a "spiral resonator for plasma generation" (Japanese Patent Application No. Hei 9-343850). .

By the way, in the above plasma processing,
In order to maintain a stable plasma and processing rate, it is important to control the oscillation frequency of the high-frequency power supply and the degree of vacuum in the vacuum chamber with high accuracy.However, the electrical components of the high-frequency power supply and the pressure gauge in the vacuum chamber are subject to aging. Can cause madness. Therefore, for the high frequency power supply,
A high-frequency wattmeter is used, and a standard pressure gauge is used for the pressure gauge.

[0007]

The above-described inspection of the high-frequency power supply and the pressure gauge is performed by separately attaching a high-frequency power meter to the high-frequency power supply or attaching a pressure gauge to a pressure gauge inspection device provided with a standard pressure gauge. This is a time-consuming task,
Since the plasma processing apparatus must be completely stopped and executed, this is a major factor in lowering the operation rate of the line.

The present invention has been made in view of the above circumstances, and has as its object to generate a high-frequency plasma in a vacuum chamber and to control the oscillation frequency of a high-frequency power supply in accordance with a change in load impedance. It is an object of the present invention to provide a method of inspecting a high-frequency power supply and a pressure gauge that can more easily and quickly inspect a high-frequency power supply and a pressure gauge in plasma processing.

[0009]

In order to solve the above-mentioned problems, the present invention has two aspects, and a method for inspecting a high-frequency power supply in a plasma processing according to a first aspect of the present invention is to generate a high-frequency plasma in a vacuum chamber. At the same time, in the plasma processing of the method of controlling the oscillation frequency of the high-frequency power supply so that the load impedance is minimized, the output and the oscillation frequency of the high-frequency power supply are detected and compared with these relational data stored in an appropriate state in advance. Thus, the quality of the high-frequency power supply is determined.

In the above inspection method, it is determined whether or not the actual function of the high-frequency power supply is normal based on the relationship between the output of the high-frequency power supply and the oscillation frequency in an appropriate state where the load impedance is minimized. Therefore, the high frequency power supply can be easily and quickly inspected by utilizing the idle time of the plasma processing apparatus.

[0011] A method of testing a pressure gauge in a plasma process according to a second aspect is characterized in that a high-frequency plasma is generated in a vacuum chamber and the oscillation frequency of a high-frequency power supply is controlled so as to minimize load impedance. In the processing, the degree of vacuum of the vacuum chamber and the oscillation frequency of the high-frequency power supply are detected and compared with these related data stored in an appropriate state in advance to determine the quality of the pressure gauge attached to the vacuum chamber. Features.

In the above inspection method, the actual function of the pressure gauge attached to the vacuum chamber is determined based on the relationship between the degree of vacuum of the vacuum chamber and the oscillation frequency of the high-frequency power supply in an appropriate state where the load impedance is minimized. Determine whether it is normal. Therefore, the pressure gauge can be easily and quickly inspected by utilizing the idle time of the plasma processing apparatus.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for inspecting a high-frequency power supply and a method for inspecting a pressure gauge in plasma processing according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an outline of a power supply control device and a test circuit of a high-frequency power supply applied to a plasma processing apparatus. FIG. 2 is a block diagram showing another embodiment of the power supply control device and the inspection circuit in FIG. FIG. 3 is a block diagram illustrating an outline of a power supply control device and an inspection device of a high-frequency power supply applied to the plasma processing apparatus. FIG. 4 is a block diagram showing another embodiment of the power supply control device and the inspection device in FIG.
FIG. 5 is a graph showing the relationship between the supplied power and the plasma frequency at a predetermined degree of vacuum in the vacuum chamber. FIG.
4 is a graph showing a relationship between the degree of vacuum in a vacuum chamber and a plasma frequency in the plasma processing apparatus.

As shown in FIGS. 1 and 2, the inspection method of the present invention generates a high-frequency plasma in a vacuum chamber of a plasma processing apparatus (1) and a high-frequency power supply (2) so as to minimize load impedance. This is a method for inspecting the quality of a high-frequency power supply (2) in plasma processing of a method for controlling the oscillation frequency of the above, and a method for inspecting the quality of a pressure gauge (9) attached to a vacuum chamber.

In the plasma processing, a plasma processing apparatus (1)
By supplying high-frequency power from a high-frequency power supply (2) (only essential parts are shown), plasma is excited in the plasma processing apparatus (1), and for example, dry etching, ion etching, ashing, plasma deposition, etc. This is a dry process.

The plasma processing apparatus (1) is an apparatus known by a name such as a plasma reactor, a wafer processing apparatus, a substrate processing apparatus, a heat treatment apparatus, and a heating processing apparatus. It mainly comprises a vacuum chamber (reaction vessel) having a gas discharge pipe connected to a vacuum system, and a metal cylinder disposed inside the vacuum chamber. Such an apparatus includes a batch method and a single-wafer method depending on the processing method of the substrate, but generally uses a coaxial power supply type, a counter electrode type, or the like from a plasma generation structure centering on electrodes.

In the above-mentioned substrate processing, it is necessary to promote a reaction by radicals and to reduce ion damage as much as possible, or to avoid ion bombardment in order to define a selection ratio with high accuracy in etching or the like. As the plasma processing apparatus (1), an apparatus using a helical resonance coil that resonates in all wavelength modes is preferable (see International Publication WO97 / 21332). According to such a device, the standing voltage is induced by the resonance coil, thereby canceling the phase voltage and the antiphase voltage with each other, so that the inductively coupled plasma having a very low potential can be excited at the node having the zero potential. Note that the impedance of each of the above-described plasma processing apparatuses is usually set to 50 ohms based on usage standards and the like.

As the high-frequency power supply (2), any suitable power supply can be used as long as it can supply power of a necessary voltage and frequency to the plasma processing apparatus (1).
A high-frequency generator (Rf generator) capable of supplying about 0.5 to 5 kW of power at 0 kHz to 800 MHz is used. Specifically, there is a fixed-frequency high-frequency power supply (frequency: 27.12 MHz, output: 3 KW) known as “CX-3000” manufactured by Comdel Inc. In addition, a pulse generator of 0 to 50 MHz known as Hewlett-Packard's trade name "HP116A" and a trade name "TCCX35 made by IFI Co., Ltd."
By using a high-power, high-band amplification known as "00", 2 kHz in the 800 kHz to 50 MHz frequency range is achieved.
A variable frequency power supply capable of outputting W can be configured.

The high frequency power supply (2) includes at least an amplifier (4) for amplifying to a predetermined output, includes a preamplifier (not shown), and is controlled by a power supply control device (3A) for defining an oscillation frequency and an output. Is done. Of course,
The power supply control device (3A) may be configured as a part of the high frequency power supply (2). That is, in the high-frequency power supply (2), the power supply control device (3A) controls the amplifier (4) based on preset output conditions related to frequency and power, and the amplifier (4) controls the plasma processing device (1). , A constant high-frequency power is supplied through a transmission line (5).

In the present invention, the reduction of the effective load power is prevented by matching the oscillation frequency so that the load impedance is minimized in accordance with the change in the impedance of the plasma processing apparatus (1) during plasma generation. In addition, a stable plasma is generated, and the substrate or the like is subjected to the above processing. Therefore, as the power supply control device (3A) of the high-frequency power supply (2), a control device having a specific frequency control function is used in order to match the oscillation frequencies as described above.

For example, as shown in FIG. 1, the power supply control device (3A) includes an A / D converter (31) for digitally converting a control analog signal into a frequency signal, and stores the value of the converted frequency signal and a preset value. An arithmetic processing circuit (32) for calculating an appropriate oscillation frequency based on the value of the obtained oscillation frequency;
A D / A converter (33) that converts the value of the frequency obtained by the arithmetic processing into a voltage signal into an analog signal, and a voltage controlled oscillator (34) that oscillates according to the applied voltage from the D / A converter (33) Be composed. Then, the power supply control device (3A) has a function of adjusting the oscillation frequency of the high-frequency power supply (2) so that the reflected wave power detected by the reflected wave power meter (6) on the output side is minimized.

That is, on the output side of the amplifier (4), a reflected wave power meter (6) is provided as a part of the high-frequency power supply (2). The reflected wave power generated by such factors as the above is detected, and the voltage signal is fed back to the A / D converter (31) of the frequency control means (3). The arithmetic processing circuit (32) calculates a frequency shift corresponding to the reflected wave power, increases or decreases the oscillation frequency so that the reflected wave power is minimized, and outputs a voltage via the D / A converter (33). A voltage is output to the control oscillator (34). Then, the voltage controlled oscillator (34) gives a frequency signal of an accurate resonance frequency under the plasma condition to the amplifier (4).

Further, in addition to or instead of the frequency control function based on the reflected wave power, the power supply control device (3A) includes a phase detection device installed between the power supply control device (3A) and the plasma processing device (1). A function of adjusting the oscillation frequency may be provided so that the phase difference between the voltage and the current detected by the detector (7) becomes 0 °.

In the frequency control based on the phase difference, a phase detector (7) is provided at the output side of the amplifier (4), and the phase detector (7) controls the voltage of the traveling wave power in the transmission line (5) and the voltage of the traveling wave power. The phase difference of the current is detected, and the voltage signal is A / D
The feedback is provided to the converter (31). The arithmetic processing circuit (32) calculates a frequency shift corresponding to the phase shift, and increases or decreases the oscillation frequency so that the above-mentioned phase difference of the traveling wave power in the transmission line (5) becomes 0 °. And
As described above, the arithmetic processing circuit (32) outputs a voltage to the voltage controlled oscillator (34) via the D / A converter (33), and supplies the corrected frequency signal to the amplifier (41).

The power supply control device (3A) includes a D / A converter (33) and a voltage controlled oscillator (34),
As shown in FIG. 2, a digital I / O (35) for digitally outputting a frequency value obtained by the arithmetic processing and a digital signal according to a signal from the digital I / O (35) are synthesized, It may be constituted by a frequency generator (36) of a direct digital synthesis system for generating a frequency signal based on such a synthesized signal. In the power supply control device (3A) shown in FIG. 2, the arithmetic processing circuit (32) digitally outputs to the frequency generator (36) via the digital I / O (35), and the frequency signal corrected as described above. Is applied to the amplifier (41) in the same manner as in the embodiment of FIG.

FIG. 1 shows an embodiment of a power supply control device (3A) using an analog type voltage controlled oscillator, and FIG. 2 shows a power supply control device (3A) using a digital type frequency generator. Is shown.

In the present invention, the frequency control function of the power supply control device (3A) as described above minimizes the reflected wave power from the plasma processing device (1) and / or reduces the voltage and current. The oscillation frequency of the high-frequency power supply (2) is controlled by signal processing so that the phase difference becomes 0 °, and the impedance mismatch generated in the plasma processing apparatus (1) due to capacitive coupling or the like is removed from the high-frequency power supply (2). Since the power is complemented on the side, power transfer efficiency can be maximized and stable plasma can be formed.

In the plasma processing apparatus (1), the frequency of the plasma changes depending on the amount of power supplied to the vacuum chamber. Specifically, as shown in FIG. 8, when oxygen is supplied at a constant flow rate and the magnitude of the supplied high-frequency power is changed while maintaining the degree of vacuum in the vacuum chamber at a constant level, the plasma is not supplied. The frequency of occurrence upper limit changes. FIG. 8 shows that when the degree of vacuum is kept at 1500 mTorr and the power of the high frequency power supply (2) is gradually increased in the range of 2.5 to 4.5 KW, the plasma frequency is about 27.
When the plasma frequency is changed in the range of 08 to 27.18 MHz, the degree of vacuum is maintained at 2000 mTorr, and the power is increased in the same range, the plasma frequency becomes about 27.08 to 27.18 MHz.
It shows that the frequency changes in the range of 13 MHz.

Therefore, in the inspection method of the high-frequency power supply (2) according to the present invention, the output and the oscillation frequency of the high-frequency power supply (2) are detected and compared with the related data stored in a proper state in advance. The quality of the high frequency power supply (2) is determined. Such an inspection, as shown in FIGS. 1 and 2,
This is performed using the power supply control device (3A) of the high-frequency power supply (2).

Specifically, a frequency for converting an output signal from the voltage controlled oscillator (34) into a voltage signal and feeding it back to the A / D converter (31) is provided on the output side of the voltage controlled oscillator (34). / Voltage converter (37) is provided. The output side of the amplifier (4) is connected to the amplifier (4).
A traveling wave power meter (8) for feeding back the output from the A / D converter to the A / D converter (31) is provided.
Further, the arithmetic processing circuit (32) of the power supply control device (3A) has a storage device (3) for storing the above related data.
9) is attached.

Then, the power supply control device (3
In A), a digital I / O (38) for digitally outputting a determination signal as a test result is provided on the output side of the D / A converter (33). Further, in the power supply control device (3A) of the embodiment of FIG. 2, a discrimination signal as a test result is directly output from the digital I / O (35).

That is, the high frequency power supply (2) according to the present invention.
In the inspection method of (1), a numerical table of an appropriate relationship between the high-frequency power (output) and the oscillation frequency at each set vacuum degree of the vacuum chamber is stored in advance in the storage device (3A) of the power control device (3A).
9). Normally, when defining the relationship between high-frequency power and oscillation frequency, a certain allowable range is provided.

In the inspection, the output from the traveling wave power meter (8) provided in the high frequency power supply (2) is detected,
Further, the oscillation frequency applied to the high frequency power supply (2) is detected by the frequency / voltage converter (37). Further, the power setting is appropriately changed while the degree of vacuum is kept constant, and the oscillation frequency at that time is detected and input to the arithmetic processing circuit (32). Then, in the arithmetic processing circuit (32), the measured data under each condition is compared with the numerical value table of the storage device (39). Is determined.

In other words, in the inspection method of the present invention, the actual function of the high-frequency power supply (2) is based on the relationship between the output of the high-frequency power supply (2) and the oscillation frequency in an appropriate state where the load impedance is minimized. Is determined to be normal.
Therefore, according to the inspection method of the present invention, the high-frequency power source (2)
It is not necessary to attach a high-frequency power meter to the transmission line (5) to inspect the power supply, and it is not necessary to completely stop the plasma processing apparatus (1). In addition, the high frequency power supply (2) can be inspected quickly.

In the plasma processing, when high-frequency power is supplied at a constant power, the frequency of the plasma changes due to a change in the degree of vacuum in the vacuum chamber. Specifically, as shown in FIG. 6, for example, when a high-frequency power of 4.5 KW is supplied while the degree of vacuum in the vacuum chamber is maintained at 2000 mTorr, the plasma is discharged at about 27.02 MHz, and is discharged for several minutes. Thereafter, stable plasma is maintained at a frequency of about 27.12 MHz or less. When the pressure of the vacuum chamber is changed by adjusting the flow rate of the material gas (oxygen) and the plasma is excited under the same conditions as above, the upper limit of the plasma frequency is increased as shown in the figure. And it tends to fall gradually. In addition, the power of the reflected wave from the vacuum chamber (plasma source) side becomes minimum when the pressure in the vacuum chamber is in the range of about 2000 to 4000 mTorr.

Therefore, in the inspection method of the pressure gauge (9) according to the present invention, the degree of vacuum of the vacuum chamber and the oscillation frequency of the high frequency power supply (2) are detected and stored in advance under the condition that the set power is set constant. The quality of the pressure gauge (9) attached to the vacuum chamber is determined by comparing the data with the relevant data in the appropriate state. Such an inspection is also performed by the power supply control device (3) of the high-frequency power supply (2) as shown in FIGS.
It can be implemented using A).

That is, in the inspection method of the pressure gauge (9),
A numerical table of an appropriate relationship between the degree of vacuum and the oscillation frequency at each set power applied to the vacuum chamber is stored in advance in the storage device (39) of the power supply control device (3A). Normally, when defining the relationship between the degree of vacuum of the vacuum chamber and the oscillation frequency, a certain allowable range is set.

In the inspection, the plasma processing apparatus (1)
The degree of vacuum of the vacuum chamber is detected by a pressure gauge (9) provided in the apparatus, and the oscillation frequency of the high frequency power supply (2) is detected by a frequency / voltage converter (37). Furthermore,
In the appropriate plasma generation region in the range of about 2000 to 4000 mTorr as described above, the setting of the degree of vacuum is appropriately changed, and the degree of vacuum and the oscillation frequency are similarly detected. Then, the measurement data (each detected value) inputted to each is compared in the arithmetic processing circuit (32) with the numerical value table of the storage device (39). It is determined that there is.

In other words, in the above-described inspection method, the vacuum chamber is attached to the vacuum chamber based on the relationship between the degree of vacuum of the vacuum chamber and the oscillation frequency of the high frequency power supply (2) in an appropriate state where the load impedance is minimized. It is determined whether or not the actual function of the pressure gauge (9) is normal. Therefore,
According to the inspection method of the present invention, it is not necessary to remove the pressure gauge (9) from the plasma processing apparatus (1) and perform a comparative inspection using a standard pressure gauge, and the plasma processing apparatus (1) is not required. It is not necessary to completely stop the pressure gauge, and the pressure gauge (9) can be inspected very easily and quickly by utilizing idle time before and after the process.

As shown in FIGS. 3 and 4, each inspection method of the present invention can be carried out by an inspection device (3B) separately prepared. The inspection device (3B) includes an arithmetic processing circuit (32b) for comparing and determining the measured data;
A storage device (39b) in which a numerical value table as a reference is stored in advance, and is configured to be able to output a determination signal from the arithmetic processing circuit (32b). The division between FIG. 3 and FIG.
FIG. 3 shows an embodiment of a power control device (3A) using an analog type voltage controlled oscillator, and FIG. 4 shows a digital type frequency generator. 2 shows an embodiment of the power supply control device (3A).

That is, the power supply control device (3
In A), the control signal of the oscillation frequency is digitally output as a test signal through a digital I / O (38) provided on the output side of the D / A converter (33). Further, the power supply control device (3
In A), an inspection signal is extracted from a digital I / O (35) that outputs a control signal of an oscillation frequency to a frequency generator (36). In the embodiment shown in FIG. 3, a traveling wave power signal is provided from a traveling wave power meter (8) provided on the output side of the amplifier (4), an oscillation frequency signal is provided from a digital I / O (38), and a pressure A signal of the degree of vacuum is input to the inspection device (3B) from the meter (9). On the other hand, in the embodiment of FIG. 4, the oscillation frequency signal is output from the digital I / O (35) to the inspection device (3B).
Is input to

In the inspection of the high frequency power supply (2), a numerical table of an appropriate relation between the high frequency power (output) and the oscillation frequency at each set vacuum degree of the vacuum chamber is stored in the storage device (39b) in advance. In the inspection applied to the power supply control device (3A) shown in FIG. 3, the output (traveling wave power) of the high frequency power supply (2) is detected by the traveling wave power meter (8), and the arithmetic processing circuit (32) The oscillation frequency of the high frequency power supply (2) specified in
Import from (38).

On the other hand, in the inspection applied to the power supply control device (3A) shown in FIG. 4, the oscillation frequency of the high frequency power supply (2) is taken in from the digital I / O (35). And
In any case, each input measurement data (each detection value) is compared with a numerical table of the storage device (39b) in the arithmetic processing circuit (32b), and the quality of the high-frequency power supply (2) is determined in the same manner as described above. Determine. In such an inspection method,
Similarly to the above-described method, the quality of the high-frequency power supply (2) can be inspected very easily and quickly by utilizing the idle time before and after the process.

In the inspection of the pressure gauge (9), a numerical table of an appropriate relationship between the degree of vacuum and the oscillation frequency at each set power applied to the vacuum chamber is stored in the storage device (39b) in advance. The power supply control device (3
In the inspection applied to A), the degree of vacuum in the vacuum chamber is detected by a pressure gauge (9) provided in the plasma processing apparatus (1), and the oscillation frequency of the high-frequency power supply (2) is determined by digital I / O. Import from (38).

On the other hand, in the inspection applied to the power supply control device (3A) shown in FIG. 4, the oscillation frequency of the high frequency power supply (2) is taken in from the digital I / O (35) in the same manner as described above. In any case, the input measurement data (each detection value) is compared with the numerical value table of the storage device (39b) in the arithmetic processing circuit (32b), and the pressure gauge (9) is compared with the above-described method. Pass / fail is determined. In such an inspection method as well, the quality of the pressure gauge (9) can be inspected very easily and quickly by utilizing the idle time before and after the process, as in the above-described method.

The present invention can be similarly applied to the case where the above-described power supply control device for matching the oscillation frequency of the high-frequency power supply according to the variation in the impedance on the process side is configured as a frequency matching device.

[0047]

As described above, according to the method of testing a high-frequency power supply according to the present invention, the relationship between the output of the high-frequency power supply and the oscillation frequency in an appropriate state where the load impedance is minimized is determined. In order to determine whether the function of the high-frequency power supply is normal or not, the high-frequency power supply can be inspected very easily and quickly using idle times before and after the process. Similarly, according to the pressure gauge inspection method according to the present invention, the function of the pressure gauge of the vacuum chamber is based on a predetermined relationship between the degree of vacuum of the vacuum chamber and the oscillation frequency of the high-frequency power supply in the above-described appropriate state. In order to determine whether the power supply is normal or not, the high frequency power supply can be inspected very easily and quickly using idle times before and after the process.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an outline of a power supply control device and an inspection circuit of a high-frequency power supply applied to a plasma processing apparatus.

FIG. 2 is a block diagram showing another embodiment of the power supply control device and the inspection circuit in FIG. 1;

FIG. 3 is a block diagram illustrating an outline of a power supply control device and an inspection device of a high-frequency power supply applied to the plasma processing apparatus.

FIG. 4 is a block diagram showing another embodiment of the power supply control device and the inspection device in FIG. 3;

FIG. 5 is a graph showing a relationship between supply power and plasma frequency at a predetermined degree of vacuum in a vacuum chamber.

FIG. 6 is a graph showing the relationship between the degree of vacuum in a vacuum chamber and the plasma frequency in a plasma processing apparatus.

[Explanation of symbols]

 1: plasma processing apparatus 2: high-frequency power supply 3A: power supply control apparatus 31: A / D converter 32: arithmetic processing circuit 33: D / A converter 34: voltage-controlled oscillator 36: frequency generator 37: frequency / voltage converter 38: Digital I / O 39: storage device 3B: inspection device 32b: arithmetic processing device 39b: storage device 4: amplifier 5: transmission line 6: reflected wave power meter 7: phase detector 8: traveling wave power meter 9: pressure gauge

Claims (2)

[Claims] 1. In a plasma process of generating a high-frequency plasma in a vacuum chamber and controlling an oscillation frequency of a high-frequency power supply so as to minimize load impedance, an output and an oscillation frequency of the high-frequency power supply are detected and stored in advance. A method for inspecting a high-frequency power supply in a plasma process, comprising determining whether the high-frequency power supply is good or not by comparing the obtained data with the relevant data in an appropriate state. 2. A plasma processing method for generating high-frequency plasma in a vacuum chamber and controlling the oscillation frequency of a high-frequency power supply so as to minimize load impedance, wherein the degree of vacuum in the vacuum chamber and the oscillation frequency of the high-frequency power supply are detected. A method for inspecting a pressure gauge in a plasma process, wherein the quality of a pressure gauge attached to a vacuum chamber is determined by comparing the relational data in a proper state stored in advance.