JP2003037101A - Helical resonance apparatus for plasma generation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a helical resonance apparatus improved in order to easily correspond to resonance characteristics with changed treatment conditions wherein, the apparatus is for generation of plasma applied to a plasma treatment unit for etching, ashing, CVD or the like on semiconductor substrates and the like. SOLUTION: The helical resonance apparatus for generation of plasma is equipped with a resonator (1) consisting of a container (11) composed decommpressible and supplied with gas for plasma, resonance coil (12) and an electrically grounded outer shield (13), and is provided with a high frequency power source (2) for supplying high frequency power. The coil (12) is composed in such a manner that the grounding position can be selected according to treatment conditions in order to be compatible with load impedance of the resonator (1) at a side of the power source (2).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral resonance apparatus for plasma generation applied to a plasma processing apparatus that performs processing such as etching, ashing, and CVD on a semiconductor substrate and the like, and is compatible with changes in processing conditions. The present invention relates to a spiral resonance device for plasma generation whose resonance characteristics can be easily adjusted.

[0002]

2. Description of the Related Art A plasma processing apparatus is used for various dry processing such as dry etching, ion etching, ashing, and plasma deposition on a semiconductor substrate. In this type of processing, for example, in the CVD processing, it is required to promote reactions by radicals and reduce ion damage as much as possible. That is, excess ions can mix materials between layers in the substrate, destroy oxides,
Causes invasion of pollutants and changes in traits. In addition, in etching processes that specify the selection ratio with high accuracy,
It is preferred to avoid ion bombardment which results in low selectivity.

The inventors of the present invention have intensively studied to obtain a plasma having a low potential, and as a result, a standing wave is induced by a coil (helical resonance coil) that resonates in all wavelength modes, and is induced in a decompression container. By generating an electric field, the phase voltage and the anti-phase voltage are canceled each other, and at the switching point of the phase voltage, that is, at the node where the potential is substantially zero, a spiral resonance device capable of exciting plasma having an extremely low potential by inductive coupling. A technique has been found, and a patent has already been applied for as a "plasma discharge treatment method by inductive coupling" (see Japanese Patent Publication No. 2000-501568).

[0004]

By the way, in the above-described spiral resonance device, when it is applied to only one type of processing, the resonance characteristics (resonance frequency and impedance) may be set in advance. Actually, when it is not applied to some processes, the resistance component of the plasma itself and the capacitive coupling between the voltage part of the resonance coil and the plasma differ depending on the type of the plasma (processing condition).
Due to the change of the processing condition, the resonance characteristics of the resonator are shifted,
There is a problem that the plasma potential becomes high. In particular, mismatch of the load impedance of the plasma generation circuit with the impedance on the power source side due to capacitive coupling or inductive coupling of plasma causes a reduction in effective load power.

However, in the conventional coaxial power supply type or counter electrode type plasma apparatus, an LC network circuit (matching circuit) is provided for adjusting the fluctuation of impedance in the plasma generating circuit on the container side and increasing the power transfer efficiency. Has been. However, the matching circuit consumes power because it functions as a part of the plasma generating circuit, and the response speed of the variable capacitor is slow and the plasma state constantly fluctuates. The reality is that no match has been obtained.

The present invention has been made to further enhance the utility of the above-mentioned spiral resonance device, and its purpose is to:
A spiral resonance device for plasma generation applied to a plasma processing apparatus that performs processing such as etching, ashing, and CVD on a semiconductor substrate, etc., so that resonance characteristics can be easily adapted in response to changes in processing conditions. An object is to provide an improved spiral resonator for plasma generation.

[0007]

In order to solve the above-mentioned problems, a spiral resonance apparatus for plasma generation according to the present invention is provided with a container configured to be decompressible and supplied with a plasma gas, and an outer periphery of the container. And a high-frequency power supply for supplying high-frequency power of a predetermined frequency to the resonance coil, and a resonance coil wound around the resonance coil and an outer shield arranged around the resonance coil and electrically grounded. And the electrical length of the resonance coil is an integral multiple of one wavelength at the predetermined frequency or a half wavelength or 1/4.
In a spiral resonance device for plasma generation set to a length corresponding to a wavelength, the resonance coil has a ground position according to a processing condition so that a load impedance of the resonator matches an impedance on the high frequency power supply side. Is configured to be selectable.

That is, the structure in which the grounding position can be selected in the resonance coil is suitable for the resonator because the load impedance of the resonator can be immediately matched with the impedance on the high frequency power source side according to the processing conditions. Resonance characteristics can be obtained, and high frequency power can be supplied to the maximum.

Further, in the above-mentioned spiral resonance apparatus for plasma generation, in order to more easily select the grounding position of the resonance coil, a vacuum relay interposed between the resonance coil and the outer shield grounds the resonance coil. It is preferable that the position can be switched.

Further, in each of the above-described spiral resonance devices for plasma generation, in order to further improve the power transfer efficiency, the high frequency power source has a reflected wave power detected by a reflected wave power meter installed on the output side thereof. A frequency matching device that adjusts the oscillation frequency so as to minimize can be attached.

Further, in each of the above-described spiral resonance devices for plasma generation, in order to further improve the power transfer efficiency, the high frequency power supply has a voltage and a current detected by a phase detector installed on the output side thereof. A frequency matching device that adjusts the oscillation frequency so that the phase difference becomes 0 ° may be additionally provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a spiral resonance apparatus for plasma generation according to the present invention will be described with reference to the drawings. Figure 1
FIG. 3 is a vertical cross-sectional view showing the outline of a spiral resonance device for plasma generation applied to a plasma processing device. FIG. 2 is a block diagram showing an example of the grounding position selecting means in the resonance coil. 3 to 5 are waveform charts showing the relationship between the grounding position of the resonance coil and the electrical characteristics of the resonator. 6 and 7 are circuit block diagrams each showing a configuration example of a frequency matching device provided in a high frequency power supply. In the following description of the embodiments, the spiral resonance device for plasma generation is abbreviated as “spiral resonance device”. Further, a semiconductor substrate or a semiconductor element as an object to be processed is abbreviated as “substrate”.

The spiral resonance apparatus of the present invention is an apparatus mainly applied to a plasma processing apparatus, and as shown in FIG. 1, a container (11) configured to be decompressible and supplied with a plasma gas, A resonator (1) including a resonance coil (12) wound around the outer circumference of the container and an outer shield (13) arranged on the outer circumference of the resonance coil and electrically grounded, and a resonance coil ( 12) is provided with a high frequency power supply (2) for supplying high frequency power of a predetermined frequency.

The container (11) is usually a so-called chamber which is formed of high-purity quartz glass or ceramics into a cylindrical shape. When applied to a plasma processing apparatus, the container (11) is usually arranged so that its axis is vertical, and the upper and lower ends are hermetically sealed by a top plate (42) and a substrate processing chamber (5) of the plasma processing apparatus described later. It is sealed. Container (1
An exhaust pipe (41) connected to a vacuum pump and for evacuating the inside of the container (11) is provided below (1) the substrate processing chamber of the plasma device, and an upper part (top plate) of the container (11) is provided. A gas supply pipe (43) extending from the material gas supply equipment and supplying a required plasma gas is attached to (42).

Since the resonance coil (12) forms a standing wave having a predetermined wavelength, the winding diameter, the winding pitch, and the number of windings are set so as to resonate in the constant wavelength mode. That is, the electrical length of the resonance coil (12) is an integral multiple (1) of one wavelength at a predetermined frequency of the power supplied from the high frequency power supply (2).
Double, double, ...) Or a length corresponding to a half wavelength or a quarter wavelength.

Specifically, the resonance coil (12) is, for example, 800 kHz to 50 MHz, in consideration of the power to be applied, the strength of the magnetic field to be generated, the outer shape of the applied device, and the like.
In order to be able to generate a magnetic field of about 0.01 to 10 Gauss by a high frequency power of 0.5 to 5 kW, an effective cross-sectional area of 50 to 300 mm ² and a coil diameter of 200 to 500 mm are used. ) Is wound about 2 to 60 times on the outer peripheral side. As the material forming the resonance coil (12),
A copper pipe, a copper thin plate, an aluminum pipe, an aluminum thin plate, a material obtained by depositing copper or aluminum on a polymer belt, and the like are used. The resonance coil (12) is formed of an insulating material in a flat plate shape, and is supported by a plurality of supports vertically provided on an upper end surface of a base plate (4) of a plasma processing apparatus described later.

Further, both ends of the resonance coil (12) are electrically grounded as a fixed ground, but normally one end of the resonance coil (12) is used for fine adjustment of the electric length of the resonance coil at the time of initial device assembly. , Grounded via a movable tap (15). Reference numeral (14) in FIG. 1 indicates the other fixed ground. Further, the resonance coil (1) is arranged so that the phase and anti-phase currents flow symmetrically with respect to the electrical midpoint of the resonance coil (12).
A waveform adjusting circuit including a coil and a shield may be inserted at one end (or the other end or both ends) of 2).
Such a waveform adjusting circuit is configured as an open circuit by electrically disconnecting the ends of the resonance coil (12) or setting them in an electrically equivalent state. Further, the end of the resonance coil (12) may be ungrounded by a choke series resistance and may be DC-connected to a fixed reference potential.

The outer shield (13) is connected to the resonance coil (1
It is provided in order to shield the electric field outside of 2) and to form the capacitance component necessary for forming the resonance circuit between the resonance coil and the resonance coil. The outer shield (13) is generally constructed in a cylindrical shape using a conductive material such as aluminum alloy, copper or copper alloy. The outer shield (13) is 5 to 150 from the outer circumference of the resonance coil (12).
They are arranged at a distance of about mm. Usually, the outer shield (13) is grounded so that the potentials are equal to both ends of the resonance coil (12), but in order to accurately set the resonance number of the resonance coil (12), the outer shield (13). One or both ends of the coil may be adjusted in tap position, or a trimming capacitance may be inserted between the resonance coil (12) and the outer shield (13).

As the high frequency power source (2), the resonator (1) is used.
Various power sources such as an Rf generator may be used as long as the power source can supply the power of the voltage and frequency required for the. For example, a high frequency generator capable of supplying about 0.5 to 5 kW of power at a frequency of 80 kHz to 800 MHz is used for the plasma processing apparatus including the resonator (1).

Specifically, as the above-mentioned power source, a fixed frequency type high frequency power source (frequency: 27.30) known by the trade name "CX-3000" manufactured by Comdel Inc. is used.
12 MHz, output: 3 kW). IF
800 kHz ~ by using the high-power, high-bandwidth amplification known under the trade name "TCCX3500" manufactured by Company I with the 0-50 MHz pulse generator known under the trade name "HP116A" manufactured by Hewlett Packard.
A variable frequency power supply capable of outputting 2 kW in the frequency range of 50 MHz can be configured.

The high frequency power source (2) usually comprises at least a control circuit including a preamplifier for defining the output and an amplifier for amplifying the output to a predetermined output. That is, in the high frequency power supply (2), the control circuit controls the output of the amplifier based on the output condition preset through the operation panel, and the amplifier transmits the transmission line () to the resonance coil (12) of the resonance device (1). A constant high frequency power is output via 25). It should be noted that the transmission line (25) has a resonance coil (1) for fine adjustment of the feeding position during the initial device assembly.
2) A movable tap (2
It may be connected via 8).

By the way, the plasma generation circuit of the resonator (1) constituted by the resonance coil (12) is an RLC parallel resonance circuit, and the wavelength of the high frequency power supply (2) and the electrical length of the resonance coil (12). When the height is the same, the resonance condition of the resonator (1) cancels out the reactance component created by the capacitive component and the inductive component of the resonator (1),
It becomes pure resistance. However, the resonator (1)
In the above, since the capacitive coupling between the voltage part of the resonance coil (12) and the generated plasma or the inductive coupling between the container (11) and the plasma is different depending on the processing condition (type of plasma), With each change, the actual impedance in the resonator (1) fluctuates slightly.

Therefore, in the present invention, in order to quickly respond to changes in processing conditions, the resonance coil (12) is designed so that the load impedance of the resonator (1) matches the impedance on the high frequency power supply (2) side. The grounding position can be selected according to the processing conditions. That is, in the spiral resonance device of the present invention, as shown in FIG. 2, the resonance coil (1
A plurality of ground terminals 2) are provided including a fixed ground, and the ground terminal of the resonance coil (12) is selected according to process conditions during operation. With such a configuration, in the spiral resonance device of the present invention, the load impedance on the resonator (1) side can be optimally maintained regardless of changes in process conditions.

Specifically, as shown in FIG. 2, the ground position of the resonance coil (12) is switched by a vacuum relay (16) interposed between the resonance coil (12) and the outer shield (13). Has been made possible. As is well known, the vacuum relay (16) is a relay in which a solenoid and contacts are housed in a vacuum container, and is configured to open and close by the operation of a general relay of an external control circuit. Such a vacuum relay (16) comprises a resonant coil (12) and an outer shield (1
It is inserted in, for example, two places between 3). The insertion position is set to a position where the impedance of the resonator (1) is, for example, 50 ohms, depending on the planned process conditions. Thereby, the grounding position of the resonance coil (12) including the fixed ground (14) can be selected from, for example, three according to the change of the processing condition.

The spiral resonance apparatus of the present invention is applied to a high frequency electrodeless discharge type plasma processing apparatus for performing dry processing such as etching, ashing and CVD on a substrate or the like. As shown in FIG. 1, the plasma processing apparatus is configured by disposing the resonator (1) of the above-mentioned spiral resonator on a horizontal base plate (4) configured as a pedestal. Then, below the resonator (1), a substrate processing chamber (5) formed in, for example, a short-axis, substantially bottomed cylindrical shape for accommodating the substrate (W) is inserted through an opening of the base plate (4). It is provided in a continuous state with the container (11).

The substrate processing chamber (5) is provided with a short-axis columnar susceptor (6) for holding the substrate (W) horizontally.
The susceptor (6) may be equipped with a commonly used electrostatic chuck. Further, the susceptor (6) may be configured to be movable up and down because the substrate (W) is loaded / unloaded by a substrate transfer mechanism (not shown). The substrate (W) is loaded and discharged through a gate valve (not shown) provided on the peripheral surface of the substrate processing chamber (5).

The inside of the container (11) of the spiral resonance apparatus and the substrate processing chamber (5) are constructed so that the pressure can be reduced to a predetermined degree of vacuum through the exhaust pipe (41) attached to the bottom of the substrate processing chamber. It The material gas for plasma generation is supplied to the inside of the container (11) and the substrate processing chamber (5) through the gas supply pipe (43) provided on the top plate (42) at the upper end of the container (11). It is designed to

In the plasma processing apparatus as described above,
First, a substrate (W) as an object to be processed is a substrate processing chamber (5).
And held on the susceptor (6). Then
By driving the vacuum pump, the pressure is reduced through the exhaust pipe (41), and the pressure inside the container (11) and the substrate processing chamber (5) is reduced to, for example, 10 to 2000 mTorr. And
While maintaining the degree of vacuum in the container (11), the gas supply pipe (4
Gas for plasma is supplied through 3).

As the plasma gas, various material gases are used depending on the processing, as in the conventional processing apparatus.
For example, oxygen, hydrogen, argon, water, etc. are used in the ashing process, and fluorine, bromine, chlorine, etc. are used in the etching process. And the resonance coil (12) of the resonator (1) from the high frequency power supply (2)
High frequency power of, for example, 27.12 MHz and 2 KW is supplied to the. As a result, when the resonance coil (12) has one wavelength, an induction electric field is generated around the resonance coil (12), and a donut-shaped induction is formed at a position corresponding to an electrical midpoint of the resonance coil (12), for example, at an intermediate height of the container (11). Plasma is excited.

In the plasma processing apparatus as described above,
As the process is changed, the type and flow rate of the plasma gas to be supplied, the degree of vacuum of the container (11) of the resonator (1), and the applied high-frequency power are changed. As a result, the load impedance in the resonator (1) when plasma is generated is different. Incidentally, FIG. 3 shows the electrical characteristics of the resonator (1) whose load impedance is adjusted to 50 ohms in the state where a fixed ground is used, and FIG. 4 shows that the processing conditions are changed and the load impedance is changed. The electrical characteristics of the resonator (1) changed to 60 ohms are shown.

On the other hand, in the spiral resonance device of the present invention, since the grounding position of the resonance coil (12) can be selected according to the processing condition (process condition), it is possible to quickly respond. That is, in the spiral resonance device, the impedance of the resonator (1) changes each time the processing condition is changed, but in the present invention, a plurality of resonances provided corresponding to some preset process conditions. Since the ground terminal of the coil (12) can be selected by switching operation of the vacuum relay (16), the load impedance on the resonator (1) side at the time of plasma generation is immediately reset to, for example, 50 ohms in accordance with changes in process conditions. it can.

In other words, in the spiral resonance device of the present invention, the structure in which the ground position of the resonance coil (12) is selectable allows the load impedance of the resonator (1) to be changed to a high frequency power source ( It can be immediately matched to the impedance on the 2) side. Therefore, it is not necessary to perform the initial adjustment each time the processing condition is changed, the optimum resonance characteristic is obtained in the resonator (1), and the high frequency power can be supplied to the maximum. Incidentally, FIG. 5 shows the electrical characteristics of the resonator (1) in which the load impedance is reset to 50 ohms by turning on the vacuum relay according to the change in the processing conditions.

By the way, the electrical length of the resonance coil (12) in the spiral resonance device is, for example, 27.12 MHz.
In this case, the load impedance of the resonator (1) is adjusted to about 20 m between the feeding position of the resonance coil (12) and one of the ground positions, while the total wavelength mode is about 11 m.
A ground terminal (fixed ground (14), vacuum relay (1
6, 16)). Therefore, in such adjustment of the load impedance, only the impedance can be matched with almost no effect on the resonance frequency of the electrical characteristics.

However, as described above, the resonance coil (1
When the grounding position of 2) is switched, as a result, the electrical length of the resonance coil (12) changes and the resonance frequency also changes, although it is extremely small. Further, due to the above-mentioned capacitive coupling between the voltage portion of the resonance coil (12) and the plasma when plasma is generated, the above-mentioned inductive coupling between the container (11) and the plasma, and the like, the resonance frequency is slightly reduced. While fluctuating. In reality, the resonator (1) resonates at a frequency slightly higher than the resonance point in the unloaded state. As a result, reflected wave power is generated at a fixed resonance frequency, and the transfer efficiency of high frequency power is slightly reduced.

Therefore, in order to compensate for the decrease in the transfer efficiency of the high frequency power due to the slight variation of the resonance frequency as described above,
In a preferred embodiment of the spiral resonance device according to the present invention,
As shown in FIG. 6, the high frequency power supply (2) has a frequency matching device that adjusts the oscillation frequency so that the reflected wave power detected by the reflected wave power meter (26) installed on the output side is minimized. (3) is attached.

The frequency matching unit (3) is, as shown in FIG. 6 (a), an A / D converter (31) for digitally converting a control analog signal into a frequency signal, a value of the converted frequency signal and a preset value. An arithmetic processing circuit (32) for calculating the oscillation frequency based on the stored value of the oscillation frequency, and D for analog-converting the frequency value obtained by the arithmetic processing into a voltage signal.
It is composed of a / A converter (33) and a voltage controlled oscillator (34) that oscillates according to the voltage applied from the D / A converter (33).

Further, the frequency matching unit (3) is replaced with the D / A converter (33) and the voltage controlled oscillator (34) and, as shown in FIG. 6 (b), the value of the frequency obtained by the arithmetic processing. Digital I / O (35) for digitally outputting
A frequency generator (36) of a direct digital synthesis system that synthesizes digital signals according to signals from the digital I / O (35) and generates frequency signals based on the synthesized signals.
May be configured by.

That is, in FIG. 6, a diagram (a) shows a mode of the frequency matching device (3) in which an analog voltage controlled oscillator is used, and a diagram (b) shows a digital frequency generator. Shows an embodiment of a frequency matcher (3) in which is used. Hereinafter, the sections (a) and (b) of the diagram in FIG. 7 also show the same mode sections as in FIG.

The frequency matching unit (3) is a high frequency power source (2).
Since the reflected wave power detected by the reflected wave power meter (26) installed on the output side of the device has a function of adjusting the oscillation frequency of the high frequency power supply (2), the effective load power is adjusted. Can certainly compensate for the decrease.

Specifically, a reflected wave power meter (26) as a part of the high frequency power source (2) is provided on the output side of the amplifier (24) to detect the reflected wave power in the transmission line (25). Then, the voltage signal is fed back to the A / D converter (31) of the frequency matching device (3). Then, the frequency of the high frequency power source (2) is increased or decreased so that the reflected wave power is minimized. As a result, the slight frequency mismatch generated in the spiral resonator (1) can be complemented on the high frequency power supply (2) side.

In the spiral resonance device, as described above, high frequency power is supplied from the high frequency power supply (2) to generate plasma. At that time, the reflected wave power meter (2
6) detects the reflected wave power and outputs A of the frequency matching device (3).
Feedback to the / D converter (31). The arithmetic processing circuit (32) calculates the deviation of the resonance frequency corresponding to the reflected wave power, and outputs a corrected frequency signal so that the reflected wave power on the transmission line (25) approaches zero.

In the mode of FIG. 6A, the arithmetic processing circuit (32) outputs a voltage to the voltage controlled oscillator (34) via the D / A converter (33), and the voltage controlled oscillator (34) A frequency signal having a resonance frequency suitable for the spiral resonance device is given to the amplifier (24). On the other hand, in the mode of FIG. 6B, the arithmetic processing circuit (32) is
It is digitally output to the frequency generator (36) via O (35), and the frequency generator (36) gives the corrected frequency signal similar to the above to the amplifier (24).

That is, the frequency matching device (3) responds to the shift of the resonance state during the operation of the spiral resonance device (1), in other words, a slight fluctuation of the resonance frequency, and responds promptly by signal processing. Since the high frequency power having a frequency that accurately resonates is output to the high frequency power supply (2), the power transfer efficiency can be further maximized. Further, the frequency matching device (3) has no mechanical driving part and has a transmission line (2).
There is no power loss due to the matching device itself because it is not interposed in the middle of 5). Therefore, in the spiral resonance device of the present invention,
Since the power of the actual resonance frequency is supplied, a more accurate standing wave can be formed and a stable plasma having an extremely low potential can be maintained.

The frequency matching device (3) may be configured to adjust the oscillation frequency by the phase difference between the voltage and the current output from the high frequency power supply (2). That is, as shown in FIG. 7, the frequency matching device (3) is provided with the voltage and current detected by the phase detector (7) on the transmission line (5) provided between the frequency matching device (3) and the resonator (1). Phase difference is 0 °
Therefore, a function of adjusting the oscillation frequency of the high frequency power supply (2) is provided.

Specifically, a phase detector (27) is provided on the output side of the high frequency power source (2), and a transmission line (25) is provided.
The phase difference between the voltage and the current at the point is detected, and the voltage signal is fed back to the A / D converter (31) of the frequency matching device (3). Then, the oscillation frequency is increased or decreased so that the phase difference between the voltage and the current becomes 0 °. Thereby, the frequency matching device (3) can supplement the slight variation of the resonance frequency in the resonator (1) on the high frequency power supply (2) side.

That is, in the above spiral resonance device,
When the plasma is excited by the high frequency power, the phase detector (27) detects the phase difference between the voltage and the current of the traveling wave power, and the A / D converter (31) of the frequency matching device (3).
Give feedback to. The arithmetic processing circuit (32) calculates a shift amount of the resonance frequency corresponding to the phase shift, and increases or decreases the predetermined frequency so that the phase difference of the traveling wave power in the transmission line (25) becomes 0 °.

Then, similar to the circuit of FIG. 6, FIG.
In this mode, 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 (24). Similarly, in the mode of FIG. 7B, the arithmetic processing circuit (32) digitally outputs to the frequency generator (36) via the digital I / O (35), and the corrected frequency signal is amplified (24). ) Give to.

In other words, the frequency matching device (3) shown in FIG. 7 has no power loss, responds promptly by signal processing, and exactly resonates at a frequency similar to the frequency matching device of FIG. Since the high frequency is output to the high frequency power source (2), the efficiency of power transfer to the resonator (1) can be maximized. As a result, in the spiral resonator of the present invention, a more accurate standing wave can be formed, and stable plasma having an extremely low potential can be formed.

Since the spiral resonance apparatus of the present invention can generate a plasma having an extremely low potential, and thus can easily control the generated plasma, dry etching including ashing, ion etching, remote plasma deposition. It can be used for a wide range of processing techniques such as plasma chemical vapor deposition such as ion plasma chemical vapor deposition. Then, in addition to devices such as semiconductor elements, flat panel displays, and microfabricated products, materials such as diamond and plastic can be processed.

[0050]

According to the spiral resonance apparatus for plasma generation according to the present invention, it is possible to select a grounding position of a plurality of resonance coils provided corresponding to some preset processing conditions.
Since the load impedance on the resonator side can be immediately matched according to the change in the processing conditions, it is not necessary to perform initial adjustment every time the processing conditions are changed, and it is possible to quickly respond when the process is changed. Then, optimum resonance characteristics can be obtained in the resonator, and high frequency power can be supplied to the maximum extent.

Further, a spiral resonator for plasma generation in which a frequency matching device for adjusting the oscillation frequency so as to minimize the reflected wave power is attached to the high frequency power source, and the phase difference between the voltage and the current becomes 0 °. According to the spiral resonance device for plasma generation in which the frequency matching device for adjusting the oscillation frequency is attached to the high frequency power source, the frequency matching device responds to a slight deviation of the resonance state during operation of the spiral resonance device, and Since high-frequency power having a frequency that resonates with is output to the high-frequency power supply, the power transfer efficiency can be further maximized. Therefore, a more accurate standing wave can be formed, and stable plasma with an extremely low potential can be maintained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an outline of a spiral resonance device for plasma generation applied to a plasma processing apparatus.

FIG. 2 is a block diagram showing an example of means for selecting a ground position in a resonance coil.

FIG. 3 is a waveform diagram showing the relationship between the grounding position of the resonance coil and the electrical characteristics of the resonator.

FIG. 4 is a waveform diagram showing the relationship between the grounding position of the resonance coil and the electrical characteristics of the resonator.

FIG. 5 is a waveform diagram showing the relationship between the grounding position of the resonance coil and the electrical characteristics of the resonator.

FIG. 6 is a circuit block diagram showing a configuration example of a frequency matching device provided in a high frequency power supply.

FIG. 7 is a circuit block diagram showing a configuration example of a frequency matching device provided in a high frequency power supply.

[Explanation of symbols]

1: Resonator 11: Container 12: Resonance coil 13: Outer shield 14: Fixed ground 15: Movable tap (fixed ground) 41: Exhaust pipe 43: Gas supply pipe 2: High frequency power supply 24: Amplifier 26: Reflected wave power meter 27: Phase detector 3: Frequency matcher 5: Substrate processing room 6: Susceptor W: Substrate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shimao Yoneyama             907-8 Shimoimasuwa, Shirane-machi, Nakakoma-gun, Yamanashi Prefecture             KM Corporation Yamanashi Office (72) Inventor Vinograd Georgy             907-8 Shimoimasuwa, Shirane-machi, Nakakoma-gun, Yamanashi Prefecture             KM Corporation Yamanashi Office (72) Inventor Menagalicivilli Vladimir             907-8 Shimoimasuwa, Shirane-machi, Nakakoma-gun, Yamanashi Prefecture             KM Corporation Yamanashi Office F-term (reference) 4K030 FA04 KA15 KA30                 5F004 AA01 BA20 BB11 BD01 BD04                       CA03                 5F045 AA08 BB02 BB16 EH11 EH19

Claims (4)

[Claims] 1. A container configured to be decompressible and supplied with a plasma gas, a resonance coil wound around the outer circumference of the container, and an outer side disposed on the outer circumference of the resonance coil and electrically grounded. A resonator including a shield; and a high-frequency power supply for supplying high-frequency power of a predetermined frequency to the resonance coil, wherein the resonance coil has an electrical length that is an integral multiple of one wavelength or a half wavelength or In a spiral resonance device for plasma generation set to a length corresponding to a quarter wavelength, the resonance coil is adapted to a processing condition so that a load impedance of the resonator matches an impedance of the high frequency power supply side. A spiral resonance device for plasma generation, which is configured so that a grounding position can be selected. 2. The spiral resonance apparatus for plasma generation according to claim 1, wherein a vacuum relay interposed between the resonance coil and the outer shield is configured to switch the ground position of the resonance coil. 3. The high frequency power supply is provided with a frequency matching device for adjusting the oscillation frequency so that the reflected wave power detected by the reflected wave power meter installed on the output side is minimized. Or the spiral resonance device for plasma generation according to 2. 4. The high frequency power supply is provided with a frequency matching device for adjusting the oscillation frequency so that the phase difference between the voltage and the current detected by the phase detector installed on the output side becomes 0 °. The spiral resonance device for plasma generation according to claim 1.