WO2009150907A1

WO2009150907A1 - Plasma processing apparatus and high frequency power supplying mechanism

Info

Publication number: WO2009150907A1
Application number: PCT/JP2009/058377
Authority: WO
Inventors: 繁河西
Original assignee: 東京エレクトロン株式会社
Priority date: 2008-06-10
Filing date: 2009-04-28
Publication date: 2009-12-17
Also published as: JP2009302124A

Abstract

A plasma processing apparatus comprises a chamber (1); a lower electrode (3) that is located in the chamber (1) and that supports a wafer (W); an upper electrode (5) that is also located in the chamber (1) and opposed to the lower electrode (3); and a high frequency power supplying mechanism (20) that modulates a first high frequency, which is to be used for plasma generation, with a second high frequency that is to be used for ion acceleration, then amplifies the composite wave as formed by that modulation and then applies a high frequency power as obtained by that amplification to the lower electrode (3). The high frequency power supplying mechanism (20) comprises a first oscillator (31) for oscillating the first high frequency; a second oscillator (32) for oscillating the second high frequency; a modulator (33) for modulating the first high frequency with the second high frequency; modulation factor adjusting parts (34, 35) each for adjusting the modulation factor; a high frequency power supply (22) for amplifying the obtained composite wave to generate the predetermined high frequency power; and a matcher (23).

Description

Plasma processing apparatus and high-frequency power supply mechanism

The present invention relates to a plasma processing apparatus for performing plasma processing such as plasma etching on a substrate such as a semiconductor wafer and a high-frequency power supply mechanism used therefor.

In the manufacturing process of semiconductor devices, the application of plasma is an indispensable technology for low temperature and dry process. As processing using plasma, plasma etching is often used in which a predetermined layer formed on a substrate such as a semiconductor wafer is processed to form a predetermined pattern.

Various plasma etching apparatuses for performing such plasma etching are used, and among them, a capacitively coupled parallel plate plasma processing apparatus is the mainstream.

In the capacitively coupled parallel plate plasma etching apparatus, a pair of parallel plate electrodes (upper and lower electrodes) are disposed in a chamber, and a high frequency electric field is formed between these electrodes while introducing a processing gas into the chamber. Is plasmatized and etched. As such a parallel plate plasma etching apparatus, a relatively high-frequency first high-frequency power for plasma generation (ionization) and a relatively low-frequency first high-frequency power for accelerating ions in the plasma and drawing them into the substrate. There is known a technique in which a high frequency power of 2 is applied to a lower electrode on which a substrate is placed to control a plasma density and an electron temperature (for example, JP-A-2005-56997).

Specifically, as shown in FIG. 1, a stage 103 on which a semiconductor wafer W functioning as a lower electrode is placed on the bottom of a chamber 101 via a dielectric plate 102 made of ceramics or the like. A grounded shower head 105 that functions as an upper electrode is provided oppositely, and a processing gas for etching is introduced from the processing gas supply system 106 into the chamber 101 via the shower head 105, and a high-frequency power supply mechanism High frequency power is supplied from 110 to the stage 103 which is the lower electrode. An exhaust pipe 116 is connected to the bottom of the chamber 101, and the inside of the chamber 101 can be evacuated by the exhaust mechanism 117 via the exhaust pipe 116.

The high-frequency power supply mechanism 110 synthesizes high-frequency power from a plasma-generating high-frequency power source 111, ion acceleration high-frequency power source 112,

matchers

113 and 114 for matching each high-frequency power source with plasma impedance, and these two high-frequency power sources. The high frequency power synthesized by the synthesizer 115 is supplied to the stage 103 which is the lower electrode.

In such a parallel plate plasma etching apparatus, a processing gas for etching is introduced into the chamber 101 and evacuated to maintain the inside of the chamber 107 at a predetermined degree of vacuum. Plasma etching is performed by supplying high-frequency power having a frequency of about 100 MHz and supplying high-frequency power having a frequency of about 1 to 6 MHz from the ion acceleration high-frequency power source 112.

However, in such a conventional parallel plate plasma etching apparatus, two high-frequency power supplies and two matchers, which are large-sized devices, are required, and the apparatus becomes large and the apparatus cost is high. In order to give appropriate ion energy to the film to be etched, the power of the relatively low frequency ion acceleration high-frequency power source 112 may be adjusted. However, when the power is adjusted, the ion density also changes. End up. In order not to cause such inconvenience, it is necessary to change the frequency of the power source for ion acceleration. For this reason, a separate power source is required for each material to be etched. Although the frequency can be made variable by using a broadband power source 112 for ion acceleration, such a power source is expensive and low in efficiency and is not practical.

An object of the present invention is to provide a plasma processing apparatus capable of reducing the size and cost of the apparatus, and a high-frequency power supply mechanism used therefor.
In addition to the above, another object of the present invention is to provide a plasma processing apparatus capable of independently controlling ion energy and ion density and a high-frequency power supply mechanism used therefor.

According to the first aspect of the present invention, a processing container in which a substrate to be processed is accommodated and evacuated, a first electrode disposed opposite to the processing container, and a second electrode that supports the substrate to be processed are provided. The first high frequency of the first frequency for plasma generation is modulated by the second high frequency of the second frequency for ion acceleration, the synthesized wave formed by the modulation is amplified, and the high frequency obtained thereby A high-frequency power supply mechanism that applies power to the second electrode, the high-frequency power supply mechanism including a first oscillator that oscillates the first high frequency, and a second oscillator that oscillates the second high frequency. A modulator that modulates the first high frequency with the second high frequency, a modulation degree adjusting unit that adjusts a modulation degree when modulating the first high frequency, and amplifying a composite wave formed by being modulated with a predetermined modulation degree A high frequency power source that generates predetermined high frequency power The plasma processing apparatus is provided with a matcher for matching the high-frequency power source and the plasma impedance.

According to the second aspect of the present invention, the first electrode having the first frequency and the second electrode that supports the substrate to be processed are disposed opposite to each other in a processing chamber capable of being evacuated, A high-frequency power supply mechanism used in a plasma processing apparatus for generating plasma with a high-frequency power of the first and accelerating ions with a second high-frequency power of a second frequency to perform plasma processing on a substrate to be processed, A first oscillator that oscillates a first high frequency; a second oscillator that oscillates the second high frequency; a modulator that modulates the first high frequency with the second high frequency; A modulation degree adjustment unit for adjusting, a high frequency power source for amplifying a composite wave formed by being modulated with a predetermined modulation degree to generate a predetermined high frequency power, and a matcher for matching the high frequency power source with plasma impedance Yes The first high frequency of the first frequency for plasma generation is modulated by the second high frequency of the second frequency for ion acceleration, the synthesized wave formed by the modulation is amplified, and the high frequency obtained thereby A high-frequency power supply mechanism that applies power to the second electrode is provided.

In the first and second aspects, the second oscillator is preferably variable in frequency. It is preferable that the modulator modulates the first high frequency with the second high frequency.

The first frequency is preferably 10 to 100 MHz, and the second frequency is preferably 0.1 to 10 MHz.

The modulation degree adjustment unit adjusts the amplitude of the first high-frequency wave oscillated by the first oscillator and the amplitude of the second high-frequency wave emitted by the second oscillator. And a second amplitude adjuster.

The high frequency power source preferably has a Q value of 20 or less, for example, a Q value of about 10.

According to the present invention, the first high frequency is modulated by the second high frequency, the combined wave formed by the modulation is amplified, and the high frequency power obtained thereby is supplied to the second electrode. The high frequency power obtained by amplifying the synthesized wave is demodulated in the formed processing container, and the first high frequency power for plasma generation and the second high frequency power for ion acceleration are respectively applied. For this reason, it is only necessary to provide one high frequency power supply and one matcher for the synthesized wave, and it is possible to reduce the size and cost of the apparatus as compared with the conventional case where two of these are required.

Further, by adjusting the modulation degree, the first high-frequency power (amplitude) and the second high-frequency power (amplitude) can be adjusted separately, and the plasma density and ion density are adjusted to desired values. be able to. Since the frequency of the second oscillator that oscillates the second high frequency is variable, the ion energy can be controlled independently of the ion density by adjusting the frequency. For this reason, etching of different materials such as polysilicon and silicon oxide film, which had to be performed with different apparatuses in the past, can be realized with one apparatus.

Sectional drawing which shows an example of the conventional parallel plate plasma processing apparatus. 1 is a cross-sectional view showing a schematic configuration of a plasma processing apparatus according to an embodiment of the present invention. The figure which shows the frequency dependence of ion energy. The figure which shows the waveform of a 1st high frequency (carrier wave). The figure which shows the waveform of a 2nd high frequency (modulation wave). The figure which shows the waveform of the synthetic wave (AM modulation wave) at the time of AM-modulating the 1st high frequency as a carrier wave and the 2nd high frequency as a modulation signal. The figure which shows the spectrum of the AM modulation wave of FIG. The figure which shows the equivalent circuit of plasma. The figure which shows the mechanism of an etching.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 2 is a cross-sectional view showing a schematic configuration of a plasma processing apparatus according to an embodiment of the present invention. This plasma processing apparatus is configured as a plasma etching apparatus that performs plasma etching on a predetermined film of a semiconductor wafer (hereinafter simply referred to as a wafer) that is a substrate to be processed.

This plasma processing apparatus is configured to be airtight and has a substantially cylindrical chamber 1 into which a wafer W is loaded. At the bottom of the chamber 1 is provided a stage 3 on which a wafer W that functions as a lower electrode is placed via a dielectric plate 2 made of ceramics or the like. The stage 3 is made of metal such as aluminum, and an electrostatic chuck (not shown) for electrostatically attracting the wafer W is provided on the upper surface, and the wafer W is cooled by passing a cooling medium inside. A cooling medium flow path (not shown) is provided.

A grounded shower head 5 that functions as an upper electrode is provided in the upper part of the chamber 1 so as to face the stage 3. That is, the parallel plate electrode is comprised by the stage 3 which functions as a lower electrode, and the shower head 5 which functions as an upper electrode. The shower head 5 has a gas inlet 6 at the top, a gas diffusion space 7 inside, and a plurality of gas discharge holes 8 at the bottom. A gas supply pipe 9 is connected to the gas inlet 6, and a processing gas supply system 10 for supplying a processing gas for etching is connected to the other end of the gas supply pipe 9. Then, a processing gas for etching is supplied into the chamber 1 from the processing gas supply system 10 through the gas supply pipe 9 and the shower head 5. As a processing gas for etching, for example, a fluorocarbon gas (C _x F _y ) such as C ₄ F ₈ gas is used.

An exhaust pipe 11 is connected to the bottom of the chamber 1, and an exhaust mechanism 12 including a vacuum pump and a pressure adjustment valve is connected to the exhaust pipe 11, and the inside of the chamber 1 is exhausted by the exhaust mechanism 12. Thus, the inside of the chamber 1 is maintained at a predetermined degree of vacuum.

A high frequency power supply mechanism 20 is connected to the susceptor 3 that functions as a lower electrode. The high frequency power supply mechanism 20 uses a first high frequency of a first frequency that is a relatively high frequency for plasma generation, and a second high frequency of a second frequency that is a relatively low frequency for ion acceleration. Amplitude modulation (AM modulation) is performed, and the high frequency power formed by amplifying the AM modulated high frequency is applied to the stage 3 functioning as the lower electrode. In AM modulation, the first high frequency that is a relatively high frequency becomes a carrier wave, and the second high frequency that is a relatively low frequency becomes a modulation signal.

Here, the first high-frequency frequency (first frequency) for plasma generation is preferably a high frequency that ions cannot follow from the viewpoint of obtaining a high-density plasma, and the sheath thickness does not change much. It is preferable that it is 10 MHz or more. However, if the frequency is increased too much, the size of the electrode cannot be ignored with respect to the wavelength, and a standing wave due to a high frequency is generated, which may deteriorate the plasma distribution.

The plasma sheath thickness _Sm is generally expressed by the following equation (1).
S _m ∝ S _abs ^1/8 / ω ^1/4 · T _e ^5/16 · ε _c ^3/8 (1)
Where S _abs is the sheath absorption energy, ω is the angular frequency, _Te is the electron temperature, and ε _c is the collision energy.
(1) As apparent from the equation, the sheath thickness S _m, since the inversely proportional to 1/4 square of the angular frequency omega, but as made sheath thickness is thin frequency increases, not so much changed in a certain frequency or more. Since this frequency is normally 20 to 30 MHz, 10 MHz or more is set as a preferable range. More preferably, it is 40 to 100 MHz, for example, 60 MHz is used.

The second high-frequency frequency (second frequency) for ion acceleration is preferably in the range of 0.1 to 10 MHz, more preferably about 1 to 10 MHz from the viewpoint of forming a plasma sheath appropriate for ion acceleration. . For example, about 1 to 6 MHz is used. Here, when ion energy is E _ion , the amplitude of the applied high-frequency voltage is V _rf , and the applied excitation frequency is f, there is a general tendency as shown in FIG. That is, the value of _Eion / _Vrf changes greatly when the frequency f is between 1 MHz and 10 MHz. For this reason, the ion energy E _ion can be accurately controlled by keeping V _rf constant and changing the frequency from 1 MHz to 10 MHz.

The high-frequency power supply mechanism 20 includes an AM modulation unit 21, a high-frequency power source 22, and a matcher 23. The AM modulator 21 includes a first oscillator 31 that oscillates the first high frequency, a second oscillator 32 that oscillates the second high frequency, and a modulator 33 that modulates the first high frequency with the second high frequency. , Two

amplitude adjusters

34 and 35 for adjusting the degree of modulation, and a BP (band pass) filter 36 that transmits a specific wavelength.

Since the first oscillator 31 and the second oscillator 32 are merely small-signal oscillators, a large-scale device configuration such as a high-frequency power supply is not necessary. As the second oscillator 32, a variable frequency oscillator such as a PLL oscillator is used, and the frequency is variable between 1 and 6 MHz, for example.

The amplitude adjuster 34 is provided between the first oscillator 31 and the modulator 33 and adjusts the amplitude of the first high-frequency wave oscillated by the first oscillator 31. The amplitude adjuster 35 It is provided between the oscillator 32 and the modulator 33, and adjusts the amplitude of the second high frequency oscillated by the second oscillator 32. Modulation factor (damping ratio) k, since the amplitude of the first high-frequency is the carrier A _c, the amplitude of the second high-frequency is a modulated wave can be expressed by When _{_{A m k = A m / A}} c The degree of modulation can be adjusted by adjusting the amplitude with the

amplitude adjusters

34 and 35. As the

amplitude adjusters

34 and 35, for example, attenuators (attenuators) are used.

In the AM modulation unit 21, the first high-frequency wave oscillated by the first oscillator 31 and adjusted to a predetermined amplitude by the amplitude adjuster 34 and the second high-frequency oscillator 32 oscillated by the second oscillator 32 and adjusted to the predetermined amplitude by the amplitude adjuster 35. The second high-frequency wave is sent to the modulator 33, where the first high-frequency wave is modulated with the second high-frequency wave with a predetermined modulation degree, and a synthesized wave (AM modulated wave) formed by the modulation is The BP filter 36 is sent to the high frequency power supply 22.

The high frequency power supply 22 is a power supply of the first frequency, and thereby amplifies a synthesized wave (AM modulated wave) formed by AM modulation to obtain predetermined high frequency power. In this case, as will be described later, the high-frequency power source 22 appropriately sets the Q value represented by the following expression (2), thereby combining the first high-frequency wave and the second high-frequency wave (AM modulation wave). ) Can be amplified.
Q = (energy stored) / (energy consumed) (2)
In this case, the Q value of the high frequency power supply 22 is preferably 1 or more and 20 or less. For example, when the Q value is 10, when the frequency of the first high frequency is 60 MHz, the frequency of the second high frequency is 1. A synthesized wave formed by AM modulation at about ˜6 MHz can be amplified.

The matcher 23 is also set to the same Q value as the high frequency power supply 22. That is, the matcher 23 preferably has a Q value of 1 or more and 20 or less, and when the high frequency power supply 22 has a Q value of 10, it is preferable that the matcher 23 also has a Q value of 10. .

By applying the composite wave (AM modulated wave) formed by AM modulation in this way to the stage 3, the AM modulated wave is demodulated by plasma as will be described later, and the high frequency power based on the first high frequency and the first The high frequency power based on the high frequency of 2 is applied to the plasma.

Each component of the plasma processing apparatus is connected to and controlled by a process controller 50 having a microprocessor (computer), as shown in FIG. Connected to the process controller 50 is a user interface 51 including a keyboard for an operator to input commands and the like for managing the plasma processing apparatus, and a display for visualizing and displaying the operating status of the plasma processing apparatus. . Further, the process controller 50 executes processing on each component of the plasma processing apparatus 50 in accordance with a control program for realizing various processes executed by the plasma processing apparatus under the control of the process controller 50 and processing conditions. A storage unit 52 that can store a program for processing, that is, a processing recipe, is connected. The processing recipe may be stored in a fixed storage medium such as a hard disk, or is set at a predetermined position in the storage unit 52 while being stored in a portable storage medium such as a CDROM or DVD. May be. Furthermore, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example. Then, if necessary, an arbitrary processing recipe is called from the storage unit 52 by the instruction from the user interface 51 and is executed by the process controller 50, so that the desired processing in the plasma processing apparatus is performed under the control of the process controller 50. Is performed.

Next, the processing operation of the plasma processing apparatus configured as described above will be described.
First, the wafer W is loaded into the chamber 1 from a loading / unloading port (not shown) and placed on the stage 3. Then, while exhausting the inside of the chamber 1 by the exhaust mechanism 12, a processing gas for etching is introduced into the chamber 1 through the shower head 5 from the processing gas supply system 10, and the first high frequency is generated by the high frequency power supply mechanism 20. A high frequency power that is AM-modulated by the second high frequency is applied to the stage 3 to generate plasma. At this time, the wafer W is electrostatically attracted by an electrostatic chuck (not shown) provided on the upper surface of the stage 3.

In the AM modulation unit 21 of the high frequency power supply mechanism 20, the first high frequency oscillated by the first oscillator 31 and the second high frequency oscillated by the second oscillator 32 are amplitude-reduced by

amplitude adjusters

34 and 35, respectively. The first high frequency is AM-modulated by the second high frequency by combining with the modulator 33 while adjusting. Then, only the necessary frequency band is passed by the BP filter 36, and the passed AM modulated wave is input to the high frequency power supply 22.

Wherein the first high-frequency v _c is the carrier are as shown in FIG. 4 can be expressed by the following equation (3).
v _c = A _c cos (ωt + φ ₀ ) (3)
Where _Ac is the amplitude of the carrier wave, ω is the angular frequency of the carrier wave, and φ ₀ is the phase of the carrier wave.

The second high-frequency v _m is the modulation signal is as shown in FIG. 5, can be represented by the following equation (4).
v _m = A _m cost (4)
Here, _Am is the amplitude of the modulation signal, and p is the angular frequency of the modulation signal.

Further, the synthesized wave (AM modulated wave) v _AM (t) in the case of AM modulation is as shown in FIG. 6, and is as shown in the following equation (5).
v _AM (t) = (A _c + A _m cost) cos (ωt + φ ₀ )
= A _c (1 + kcospt) cos (ωt + φ ₀ ) (5)
However, k = A _m / A _c is a modulation degree (attenuation ratio).

When the above expression (5) is expanded, the following expression (6) is obtained, and when further expanded, the expression (7) is obtained.
v _AM (t) = A _c cos (ωt + φ ₀ ) + kA _c cospt · cos (ωt + φ ₀ ) (6)
v _AM (t) = A _c cos (ωt + φ ₀ ) +
(1/2) kA _c cos [(ω + p) t + φ ₀ ] +
(1/2) kA _c cos [(ω−p) t + φ ₀ ] (7)

As shown in the equation (7), the AM modulated wave v _AM (t) includes a carrier wave: A _c cos (ωt + φ ₀ ), an upper wave: (1/2) kA _c cos [(ω + p) t + φ ₀ ], and a lower side wave. : (1/2) kA _c cos [(ω−p) t + φ ₀ ]. The spectrum of the AM modulated wave v _AM (t) at this time is as shown in FIG.

As is apparent from FIG. 7, amplification and matching can be performed if a band of (ω + p) − (ω−p) = 2p is secured by AM modulation. Here, since the frequency of the modulation signal and f _m becomes p = 2 [pi] f _m, the half-value width B may be represented by the following equation (8).
B = 2f _m = f _BW (8)
However, f _BW is an occupied frequency band.

If the frequency of the carrier wave is f ₀ , the Q value can be expressed by the following equation (9).
Q = f ₀ / f _BW (9)

Here, assuming that the frequency f ₀ of the carrier wave is 40 MHz and f _BW is 2 MHz, Q = 40/2 = 20, and the Q values of the high-frequency power source 22 and the matcher 23 should be 20 or less.

The high-frequency power supply and matcher are more accurate as the Q value is higher, but normally, Q is about 10 in consideration of stability. Therefore, by using a general high frequency power supply 22 without being caught by an amplification operation (Class A, Class B, etc.), and by using a general purpose L and C as the matcher 23, The AM modulated wave intended in the embodiment can be amplified.

The high-frequency power amplified by the high-frequency power source 22 is changed in the electric field of both ions and electrons in the first high-frequency (carrier wave) component (ω) of about 60 MHz in the chamber 1. In contrast, the second high frequency (modulation signal) component (p) having a relatively low frequency of about 1 to 10 MHz cannot follow the change of the electric field, but the electron follows. Can do. As a result, a plasma potential is generated and an electric field is applied to the sheath to accelerate ions. As shown in FIG. 8, the equivalent circuit of the plasma at this time has a sheath part composed of a diode and a capacitor. Non-linear demodulation (diode demodulation) is achieved by a non-linear component of the diode, and an AM modulated wave is generated in the chamber 1. It can be demodulated.

Therefore, the cost and DC portions, which are the second high-frequency components, remain in the sheath portion of the plasma, and as a result, ions excited to the p angular velocity are accelerated in the sheath portion, and physical etching is performed using them. Can do.

Here, the plasma etching mechanism of the present embodiment will be described with reference to FIG. 9 in the case where the material to be etched is a thermal oxide film (SiO ₂ ). First, _(a), the plasma is generated by a mixed gas of C x _{F y} based gas and Ar inert gas such as, C, F, active particles of CF or the like is adsorbed on SiO ₂ surfaces. Thereafter, as shown in (b), Ar ions having kinetic energy collide with the SiO ₂ surface and the temperature of this portion rises, whereby the SiO ₂ and these active particles cause a chemical reaction, SF ₄ , CO, CO _{2 and the} like are formed. These reaction by-products become gas in an environment of several mTorr and are exhausted through the exhaust pipe 11, and the SiO ₂ film is etched as shown in FIG. Here, in the chemical reaction between the active particles and SiO ₂ , the reaction speed varies depending on the temperature. In the plasma etching in FIG. 9, in order to increase the etching selectivity between the SiO ₂ film and the Low-k film, the temperature of the Si substrate is maintained at a temperature at which the SiO ₂ film is easily etched and the Low-k film is difficult to etch. Although it is necessary, this temperature is determined by the energy of Ar ions. In this embodiment, ion energy is controlled to increase the selection ratio, that is, the frequency is controlled while, for example, the second high-frequency amplitude _Am is constant, and the first high-frequency amplitude A is used to increase the etching rate. _The modulation degree k is increased while keeping _c constant.

As described above, according to the present embodiment, the AM modulation unit 21 AM modulates the first high frequency with the second high frequency, and the high frequency power obtained by amplifying the AM modulated wave is demodulated in the chamber 1. The power supply and the matcher need only be provided one by one for the AM modulated wave, and it is possible to reduce the size and cost of the apparatus as compared with the conventional case where two of them are required.

In addition, since the first high frequency is modulated by the second high frequency while adjusting the modulation degree by the AM modulation unit 21, the first high frequency power (amplitude) when amplified by the high frequency power supply 22 and demodulated in the chamber 1 is used. ) And the second high frequency power (amplitude) can be adjusted separately, and the plasma density and ion density can be adjusted to desired values. Since the second oscillator 32 that oscillates the second high frequency has a variable frequency, the ion energy can be controlled independently of the ion density by adjusting the frequency. For this reason, etching of different materials such as polysilicon and silicon oxide film, which had to be performed with different apparatuses in the past, can be realized with one apparatus.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above embodiment, amplitude modulation (AM modulation) is used when modulating the first high frequency with the second high frequency, but other modulations such as frequency modulation (FM modulation) and phase modulation (PM modulation) are used. Can also be used.

In the above embodiment, plasma etching is described as an example of plasma processing, but other plasma processing may be used. Furthermore, the object to be processed is not limited to the semiconductor wafer, and other objects such as a glass substrate for FPD can be targeted.

Claims

A processing container in which a substrate to be processed is accommodated and evacuated;
A first electrode disposed opposite to the processing container and a second electrode for supporting the substrate to be processed;
The first high frequency of the first frequency for plasma generation is modulated by the second high frequency of the second frequency for ion acceleration, the synthesized wave formed by the modulation is amplified, and the high frequency power obtained thereby And a high-frequency power supply mechanism for applying to the second electrode,
The high-frequency power supply mechanism is
A first oscillator for oscillating the first high frequency;
A second oscillator for oscillating the second high frequency;
A modulator that modulates the first high frequency with the second high frequency;
A modulation degree adjustment unit for adjusting a modulation degree when modulating,
A high-frequency power source that amplifies a composite wave formed by being modulated at a predetermined modulation degree to generate a predetermined high-frequency power;
A plasma processing apparatus comprising the high-frequency power source and a matcher for matching plasma impedance.
The plasma processing apparatus according to claim 1, wherein the second oscillator is variable in frequency.
The plasma processing apparatus according to claim 1, wherein the modulator modulates the amplitude of the first high frequency with the second high frequency.
2. The plasma processing apparatus according to claim 1, wherein the first frequency is 10 to 100 MHz, and the second frequency is 0.1 to 10 MHz.
The modulation degree adjustment unit adjusts the amplitude of the first high-frequency wave oscillated by the first oscillator and the amplitude of the second high-frequency wave emitted by the second oscillator. The plasma processing apparatus according to claim 1, further comprising a second amplitude adjuster.
The plasma processing apparatus according to claim 1, wherein the high-frequency power source has a Q value of 20 or less.
A first electrode disposed opposite to the evacuable processing container and a second electrode for supporting the substrate to be processed, generating plasma with a first high-frequency power having a first frequency; A high-frequency power supply mechanism used in a plasma processing apparatus for performing plasma processing on a substrate to be processed by accelerating ions with a second high-frequency power having a frequency of
A first oscillator for oscillating the first high frequency;
A second oscillator for oscillating the second high frequency;
A modulator that modulates the first high frequency with the second high frequency;
A modulation degree adjustment unit for adjusting a modulation degree when modulating,
A high-frequency power source that amplifies a composite wave formed by being modulated at a predetermined modulation degree to generate a predetermined high-frequency power;
Having a matcher for matching the high frequency power source and plasma impedance;
The first high frequency of the first frequency for plasma generation is modulated by the second high frequency of the second frequency for ion acceleration, the synthesized wave formed by the modulation is amplified, and the high frequency power obtained thereby A high-frequency power supply mechanism for applying a voltage to the second electrode.
The high-frequency power supply mechanism according to claim 7, wherein the second oscillator is variable in frequency.
The high-frequency power supply mechanism according to claim 7, wherein the modulator modulates the amplitude of the first high frequency with the second high frequency.
The high-frequency power supply mechanism according to claim 7, wherein the first frequency is 10 to 100 MHz, and the second frequency is 0.1 to 10 MHz.
The modulation degree adjustment unit adjusts the amplitude of the first high-frequency wave oscillated by the first oscillator and the amplitude of the second high-frequency wave emitted by the second oscillator. The high-frequency power supply mechanism according to claim 7, further comprising a second amplitude adjuster.
The high-frequency power supply mechanism according to claim 7, wherein the high-frequency power source has a Q value of 20 or less.