JP3227949B2 - Plasma processing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a device using a semiconductor such as a thin film transistor and various sensors utilizing a semiconductor, a solar cell, and the like. In addition, the present invention relates to plasma processing such as plasma etching for etching a formed film according to a predetermined pattern.

[0002]

2. Description of the Related Art Various types of plasma CVD apparatuses are known. As a representative example, a parallel plate type plasma CVD apparatus shown in FIG. 5 will be described. This apparatus has a vacuum vessel 1 in which an electrode 2 also serving as a substrate holder for installing a film-forming substrate S1 and an electrode 2 Are provided.

[0003] The electrode 2 is usually a ground electrode.
A heater 21 for heating the substrate S1 mounted thereon to a film forming temperature is additionally provided. When the substrate S1 is heated by radiant heat, the heater 21 is separated from the electrode 2. The electrode 3 is a power application electrode for applying high-frequency power or DC power to the film-forming gas introduced between the electrode 3 and the plasma to generate plasma, and in the illustrated example, a high-frequency power source 32 through a matching box 31. It is connected to the.

In the illustrated example, the electrode 3 is provided with a porous electrode plate 34 at an opening of a gas nozzle 33 constituting a part of the electrode.
In the electrode plate 34, a number of gas supply holes having a diameter of about 0.5 mm are formed, so that the gas supplied from the gas nozzle 33 is discharged from each hole between the electrodes as a whole. It is. Such a configuration is suitable for forming a film on a wide-area substrate.

An exhaust pump 52 is connected to the vacuum vessel 1 via an on-off valve 51, and a gas supply unit 4 is connected to the gas nozzle 33.
The gas supply unit 4 includes one or more mass flow controllers 421, 422,... And on-off valves 431, 432.
Include gas sources 441, 442,... For supplying a predetermined amount of film forming gas via.

According to this parallel plate type plasma CVD apparatus, the substrate S1 to be formed is set on the electrode 2 in the vacuum vessel 1, and the inside of the vessel 1 is operated to a predetermined vacuum by operating the valve 51 and operating the exhaust pump 52. From the gas supply unit 4 to the nozzle 33
Further, a film forming gas is introduced through a gas supply hole of the electrode plate 34. Further, high-frequency power is applied to the high-frequency electrode 3 from the power supply 32, and the introduced gas is turned into plasma, and a desired film is formed on the surface of the substrate S1 under this plasma.

[0007] Various types of plasma etching apparatuses are also known. A parallel plate type etching apparatus shown in FIG. 6 will be described as a typical example. This apparatus also includes a vacuum vessel 10, in which an electrode 20 also serving as a substrate holder for installing a substrate S2 on which a film to be etched is formed, and An electrode 30 is provided opposite to the electrode 20.

The electrode 20 is used as a power application electrode for applying a high frequency power or a DC power to the etching gas introduced between the electrode 30 and the plasma to form a plasma. Connected to the high frequency power supply 202. The electrode 30 is a ground electrode, in which a porous electrode plate 302 is provided at an opening of a gas nozzle 301 constituting a part of the electrode. The electrode plate 302 has a large number of gas supply holes having a diameter of about 0.5 mm. In addition, the gas supplied from the gas nozzle 301 is entirely discharged from the hole between the two electrodes.

An exhaust pump 72 is connected to the vacuum vessel 10 via an on-off valve 71, and a gas supply section 6 is connected to the gas nozzle 301. One or more mass flow controllers 621, 622,... And on-off valves 631, 6
32. Gas sources 641, 642,... For supplying a predetermined amount of etching gas via 32.

According to this etching apparatus, the substrate S2 to be etched is set on the high-frequency electrode 20 in the container 10, and the inside of the container 10 is set to a predetermined vacuum by operating the valve 71 and the exhaust pump 72, An etching gas is introduced from the supply unit 6 through the gas supply holes of the nozzle 301 and the electrode plate 302. Also, a high frequency power supply 202 is connected to the electrode 20.
, A high-frequency power is applied from the substrate, and the introduced gas is turned into plasma, and the film on the substrate S2 is etched under the plasma. The electrode 20 may be cooled by a water cooling device 200 or the like as necessary.

[0011]

However, in such a plasma CVD process, fine particles generated by a gas phase reaction in plasma adhere to a film formed on the substrate surface or are mixed in the film. There is a problem that the film quality is deteriorated, and there is a problem that the generated fine particles adhere to and contaminate each part in the vacuum vessel. Fine particles adhering to various parts in the vacuum vessel may eventually peel off and adhere to the substrate to be processed.

In particular, fine particles are formed by a gas phase reaction,
It is highly likely that the film will grow greatly, for example, an amorphous silicon (a-Si) film made of silane (SiH ₄ ) and hydrogen (H ₂ ), and an amorphous silicon nitride (a) made of silane and ammonia (NH ₃ ). In the case where an amorphous silicon oxide (a-SiO ₂ ) film is formed from silane and dinitrogen monoxide (nitrous oxide) (N ₂ O), a film formed on the surface of the substrate is used. When the size of the fine particles adhering to or mixed into the film is larger than the thickness of the film to be formed, as a result, when the film is an insulating film, when the cleaning process is performed after the film formation, the fine particle portion is removed. If the film becomes a pinhole and insulation failure occurs, or if the film is a semiconductor film, there is a problem that the semiconductor characteristics are deteriorated.

[0013] In the plasma etching process, similarly, there is a problem that fine particles are formed by a gas phase reaction and adhere to a surface to be etched or adhere to various parts in a vacuum vessel. For example, in the case where a wiring pattern is formed by etching, such fine particles cause deterioration in patterning accuracy, and may cause disconnection in the formation of fine lines.

[0014] Such a problem in the plasma processing hinders high-speed film formation and high-speed etching, in which generation of fine particles increases. As a method for solving such a problem, JP-A-5-51753 and JP-A-5-1564 are known.
No. 51 teaches that in plasma CVD, high-frequency power of a predetermined frequency is pulse-modulated and applied as plasma-generating power. This is based on the fact that the lifetime of a reactive species that is considered to generate fine particles called dust and particles that deteriorates the film quality is shorter than the lifetime of a reactive species that is considered to contribute to film formation. By turning on and off with pulse modulation, it is intended to suppress the generation of fine particles by suppressing the generation of the reactive species causing dust while securing the reactive species contributing to the film formation.

Although this method has a fine particle suppression effect, the actual pulse modulation is usually performed by multiplying a fundamental frequency related to a predetermined high-frequency power by a harmonic. For this reason, complicated frequency components deviating from the main band, which is the fundamental frequency, enter the modulated power. FIGS. 3A and 3B show an example of this state. FIG.
A high-frequency power waveform after pulse modulation of a 56-MHz high-frequency power is shown, and FIG. (B) shows a result of measuring this with a spectrum analyzer. As shown in FIG. 7B, a complicated side band s enters the main band m (13.56 MHz). The energy of these other frequency components is lost as heat or reflected by the matching box, and does not contribute to plasma generation, which wastes power and hinders an improvement in the film forming rate.

Energy wasted due to sidebands is generated when plasma for etching gas is turned into plasma in plasma etching. In order to suppress the generation of fine particles that have an adverse effect on etching, power generated by performing pulse modulation on high frequency power of a predetermined frequency is generated by plasma generation. It also occurs when it is applied as power for use. Therefore, the present invention introduces a processing gas under a predetermined vacuum between opposing electrodes provided in a vacuum vessel, applies electric power to generate plasma, and applies a plasma to a substrate to be processed in the vacuum vessel under the plasma. a plasma processing method and apparatus for plasma treatment with plasma treatment or plasma etching method using a plasma CVD method, a plasma treatment can be improved compared with the conventional plasma processing rate while suppressing the occurrence of undesirable particulates into the plasma treatment It is an object to provide a method and an apparatus.

[0017]

Means for Solving the Problems The inventor of the present invention has conducted various researches to solve the above-mentioned problems. As a result, when applying high-frequency power to convert the processing gas into plasma, a high-frequency power of a predetermined frequency is converted into a sine wave. When amplitude modulation (AM modulation) is applied, the attention is paid to the fact that other frequency components outside the main band, which is the fundamental frequency, enter the modulation power to a negligible extent. FIGS. 3C and 3D show an example of this state. Figure (C) shows a fundamental frequency of 13.56 MHz.
Shows a high-frequency power waveform after amplitude modulation of the high-frequency power by a sine wave, and FIG. (D) shows a result obtained by measuring this with a spectrum analyzer. As shown in FIG. 3D, the side band s is very small in the main band m (13.56 MHz).
The present invention is based on this finding.

That is, in the plasma processing method according to the present invention for solving the above-mentioned problems, the amplitude-modulated high-frequency power in a state where the applied plasma generation power is subjected to amplitude modulation based on a sine wave to high-frequency power of a predetermined frequency. And
The basic modulation frequency is changed to the basic modulation wave by the in-wave amplitude modulation.
It is characterized in that the power is a state in which harmonics of an integral multiple of the modulation frequency are superimposed . Further, in the plasma processing apparatus according to the present invention for solving the above-mentioned problem, the means for applying the plasma generation power uses amplitude modulated high-frequency power in a state where amplitude modulation based on a sine wave is performed on high-frequency power of a predetermined frequency.
The fundamental modulation wave by the sine wave amplitude modulation.
Of harmonics with a modulation frequency that is an integral multiple of the
It is characterized by applying electric power .

In the method of the present invention, the “power in a state where amplitude modulation based on a sine wave is performed on high-frequency power of a predetermined frequency” is a predetermined frequency (for example, 13.56 MHz).
May be obtained by preparing the basic high-frequency power and performing amplitude modulation based on a sine wave, or the power in such a state from the beginning. In the case of the former power, examples of the power application means in the device of the present invention include a power supply means for providing a basic high-frequency power of a predetermined frequency, and an amplitude modulator for performing amplitude modulation on the high-frequency power provided by the power supply means. In the case of the latter power, the power applying means in the present invention includes a waveform synthesizer for generating a modulated wave in an amplitude-modulated state based on a sine wave, and an amplitude-modulated wave provided by the waveform synthesizer. Can be exemplified.

[0020] Then, the amplitude and the fundamental the sine wave modulation, 2 of the basic modulation frequency the modulated wave by sine wave amplitude modulation as shown in FIG. Shown in FIG. 3 (C) as a fundamental modulation wave
It is assumed that harmonics of an integral multiple of the modulation frequency such as double and triple are superimposed . FIG. 4A shows an example of a modulated wave in which double harmonics are superimposed, and FIG. 4B shows an example of a modulated wave in which third harmonics are superimposed.

The modulated wave power obtained by the sine wave amplitude modulation as shown in FIG. 3 (C) is not limited thereto, but as a typical example, a sine wave having a modulation frequency in the range of 100 Hz to 1 MHz is applied to a high frequency power of 13.56 MHz. The power in a state where the wave amplitude modulation is performed can be given. In this case, the modulation frequency effectively suppresses the generation of radical species that cause undesired fine particles in plasma processing, and facilitates the introduction of power for plasma generation to stably maintain plasma. Therefore, 100 Hz to 1 MHz is desirable as described above.

The modulated wave power obtained by superimposing harmonics as shown in FIG. 4A and FIG. 4B is not limited thereto, but as a representative example, a high frequency power of 13.56 MHz and a modulation frequency of 100 Hz are used. An example is power in a state where a harmonic having a modulation frequency that is an integral multiple of the basic modulation frequency is superimposed on a basic modulation wave that has undergone sine wave amplitude modulation in a range of 1 MHz. In this case as well, the modulation frequency of the fundamental modulation wave effectively suppresses the generation of radical species that cause undesired generation of fine particles in plasma processing, and facilitates the introduction of power for plasma generation to achieve stable operation. In order to maintain the plasma at 100 Hz, 100 Hz to 1 MHz is desirable as described above.

Further, when the application of high-frequency power capable of executing the plasma processing and the stop of the plasma due to the stop or decrease of the application of the high-frequency power are repeated, the behavior of the fine particles becomes so severe that the particles tend to adhere to the substrate to be processed. When the plasma stops, the fine particles trapped in the electrode or in the vicinity thereof diffuse to the substrate to be processed,
Also, the dielectric constant of the plasma changes extremely. Therefore, in the method and the device of the present invention, the behavior of the fine particles is moderated, and the fine particle trap state is maintained, or the fine particle can be transported from the trap state to the outside of the container with the evacuation from the inside of the vacuum container. Therefore, in order to prevent the dielectric constant of the plasma from being extremely changed, it is conceivable that the amplitude-modulated high-frequency power to be applied is a power that can maintain the plasma even at the minimum amplitude. In this case, the power applying means can apply such power.

[0024]

According to the plasma processing method and apparatus of the present invention,
A substrate to be processed is set at a predetermined position in a vacuum vessel, the inside of the vessel is evacuated to a predetermined vacuum state, and a processing gas is introduced. Then, when the electric power is applied, the gas is turned into plasma, and the target processing is performed on the substrate under the plasma.

The power is applied in a state where high-frequency power of a predetermined frequency is subjected to amplitude modulation based on a sine wave.
Therefore, the modulation wave by the sine wave amplitude modulation is used as the basic modulation wave,
The fundamental modulation wave has a modulation frequency that is an integral multiple of the basic modulation frequency.
This is performed with the harmonics superimposed. By applying the amplitude modulation power in this manner, the generation of fine particles that adversely affect the plasma processing is suppressed, and since the power in a state where the amplitude modulation based on the sine wave is performed is employed, the desired fundamental frequency is used. There is almost no side band (other complicated frequency components) for a certain main band, and therefore, power is wasted and power is supplied smoothly for plasma generation, and plasma processing can be performed at a higher speed.

In order to maintain the plasma even when the amplitude-modulated high-frequency power is at the minimum amplitude, the dielectric constant of the plasma is stabilized, the plasma processing is performed more smoothly, and the behavior of the fine particles is more moderate. At the same time, the fine particles trapped in the electrode or in the vicinity thereof are not diffused to the substrate to be processed, or are further transported from the trapped state to the outside of the container with the exhaust from the vacuum container.

Further, since the amplitude-modulated high-frequency power is obtained by superimposing a harmonic having a modulation frequency that is an integral multiple of the basic modulation frequency on the basic modulation wave, the amplitude modulation high-frequency power is thereby reduced by plasma CVD.
That the uniformity and film quality of the film in the film formation, also flop
The plasma processing can be variously controlled with respect to the etching uniformity in the plasma etching.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A shows a plasma CVD apparatus according to the present invention .
Fig . 2 shows a basic device of the example. This plasma CV
The D device is a high-frequency power source 32 in the conventional device shown in FIG.
Instead of using a high frequency power supply 321 of a predetermined frequency (typically 13.56 MHz) to which an amplitude modulator 322 is connected, the configuration is the same as that of the apparatus of FIG. . Parts that are the same as the parts in the apparatus of FIG. 5 are given the same reference numerals.

According to this plasma CVD apparatus, the substrate S1 to be formed is set on the electrode 2, and thereafter, the target film is formed on the surface of the substrate by the same procedure as described for the apparatus in FIG. However, in this apparatus, the power applied for plasma generation is obtained by performing amplitude modulation (AM modulation) based on a sine wave by a modulator 322 on high-frequency power of a predetermined frequency obtained from a power supply 321. .

The voltage waveform after the amplitude modulation is as shown in FIG. 1B, and is modulated so that the plasma can be maintained even at the minimum amplitude. Since the high-frequency power subjected to the amplitude modulation is applied as described above, the short-lived reactive species that cause the generation of fine particles that adversely affect the film formation disappear as shown in FIG. As a result, while the generation of fine particles is suppressed, the reactive species having a relatively long life and contributing to the film formation are maintained at a constant level as shown in FIG. A film is formed.
Also, since the plasma is maintained even at the lowest amplitude,
In this respect, the film is formed smoothly and quickly. In addition, since the plasma is maintained, the behavior of the fine particles becomes gentle, and the fine particles trapped in the electrode or the vicinity thereof do not diffuse into the substrate S1 to be processed, or furthermore, the trapped state is evacuated due to the exhaust from the vacuum chamber 1. Is transported out of the container.

Thus, as a whole, the instability of the plasma due to the fine particles is suppressed, and the adhesion and mixing of the fine particles to the substrate to be processed S1 are suppressed, so that high-speed film formation is possible and the film quality is improved. Deterioration of the characteristics of the product device and reduction of the yield are suppressed, and the vacuum vessel 1
Since the adhesion of the fine particles to the inner wall and the like is also suppressed, labor can be saved in terms of device maintenance.

The power supply 321 and the modulator 3
1, a waveform synthesizer [arbitrary waveform generator (function generator) 323] 323 and an RF amplifier 324 connected thereto, as shown in FIG.
And connecting it to the matching box 31 is also conceivable. In this way, it is also possible to apply power in a state where amplitude modulation based on a sine wave is performed on high-frequency power of a predetermined frequency.

An example in which an a-Si: H film is formed by the apparatus shown in FIG. 1A described above will be described. Film forming conditions Substrate: 5 inch silicon wafer Gas: SiH ₄ 100 sccm H ₂ 400 sccm Film forming temperature: 230 ° C. Film forming gas pressure: 0.4 Torr High frequency power: 13.56 MHz, 150 W high frequency power at modulation frequency of 900 Hz to 50 to 350 W (50 W at the minimum amplitude, 350 W at the maximum amplitude) Electrode size: 360 mm × 360 mm □ Electrode interval: 45 mm (distance between electrode 3 and substrate S1 surface) In this film formation, a-Si formed : The number of the attached fine particles in the H film was 0.3 μm or more and 5 or less, the film formation rate was 200 ° / min, and the required number of maintenance of the vacuum vessel and the like was 50 batches (total 50 μm film formation).

According to the conventional apparatus shown in FIG. 5, except that the applied power is 13.56 MHz and the high-frequency power of 150 W, the number of adhered fine particles is about 50 under the same film forming conditions.
The number was 10 batches (total film thickness of 10 μm). In one example of the plasma CVD apparatus according to the present invention,
Is the amplitude modulated high-frequency power, in FIG. 4 (A), (B)
As shown in the example, the sine wave is distorted by superimposing a harmonic of a modulation frequency that is an integral multiple of the basic sine wave modulation wave on the basic sine wave modulation wave, thereby distorting the sine wave. Control .

Next, the plasma etching apparatus according to the present invention will be described.
An apparatus serving as a basis of the example will be described with reference to FIG. This apparatus employs a conventional apparatus shown in FIG. 6 in which an amplitude modulator 204 is connected to a high frequency power supply 203 having a predetermined frequency (typically 13.56 MHz) instead of the power supply 202, and this is connected to the matching box 201. Except for this point, the configuration is the same as that of the apparatus shown in FIG. Parts that are the same as the parts in the apparatus of FIG. 6 are given the same reference numerals.

According to this plasma etching apparatus, the substrate S2 to be etched is placed on the high-frequency electrode 20, and thereafter, the film on the substrate surface is subjected to the etching process in the same procedure as described for the apparatus in FIG. However, in this apparatus, high-frequency power obtained from the power supply 203 and subjected to AM modulation based on a sine wave by the modulator 204 are supplied as power for converting the introduced etching gas into plasma. The amplitude-modulated high-frequency power can maintain the plasma even at the minimum amplitude.

Since the high-frequency power subjected to the amplitude modulation is applied as described above, the etching can be performed smoothly while suppressing the generation of fine particles that adversely affect the etching. In addition, since the plasma is maintained even when the applied modulation power has the minimum amplitude, etching is performed smoothly and quickly also in this regard. In addition, since the plasma is maintained, the behavior of the fine particles becomes gentle, and the fine particles trapped in the electrode or in the vicinity thereof do not diffuse into the substrate S2 to be processed, or furthermore, the trapped state is caused by the exhaust from the vacuum chamber 1. Is transported out of the container.

Thus, as a whole, the instability of the plasma due to the fine particles is suppressed, and the adhesion and mixing of the fine particles to the substrate S2 to be processed are suppressed, so that high-speed etching is possible and the etching uniformity is improved. In addition, the deterioration of the characteristics of the final product device and the decrease in the yield are suppressed, and the adhesion of the fine particles to the inner wall of the vacuum vessel 1 is also suppressed, so that the labor can be saved in terms of the maintenance of the apparatus.

In this etching apparatus, a waveform synthesizer and an RF amplifier connected thereto may be adopted instead of the power supply 203 and the modulator 204 and connected to the matching box 201. In this way, it is also possible to apply power in a state where amplitude modulation based on a sine wave is performed on high-frequency power of a predetermined frequency.

With the apparatus of FIG. 2 described above, a-Si
An example of etching a film will be described. Etching conditions Substrate: Substrate having an a-Si film formed on a 4-inch silicon wafer Gas: SF ₆ 40 sccm CHCl ₃ 7.5 sccm Etching temperature: 70 ° C. Gas pressure: 80 mTorr High frequency power: 13.56 MHz, modulating high frequency power of 150 W at 100 kHz AM-modulated power of 50 to 200 W (50 W is at the minimum amplitude, 200 W is at the maximum amplitude) Electrode size: 200 mm × 200 mm □ Electrode interval: 50 mm (distance between electrode 30 and surface of substrate S 2) The number of attached fine particles is 0.3
The size was 10 μm or more, the etching rate was 2400 ° / min, and the etching uniformity was 3%.

According to the conventional apparatus shown in FIG. 6, except for the applied voltage (13.56 MHz, 150 W high frequency power), the etching conditions were the same except that the number of adhered particles was about 8
0 pieces, the etching rate was 1500 ° / min, and the etching uniformity was 7%. And the plasma edge according to the present invention is
In one example of the quenching apparatus, the amplitude modulated harmonic power, FIG.
4 (A), a state obtained by distorting the sine wave superimposed harmonics as illustrated, an integral multiple of the modulation frequency of the basic modulation frequency the fundamental sine wave modulation (B), the thus-flop
It controls the etching uniformity in plasma etching.

[0042]

As described above, according to the plasma processing method and apparatus of the present invention, a processing gas is introduced under a predetermined vacuum between opposing electrodes provided in a vacuum vessel, and power is applied to generate plasma. the plasma treatment also by a plasma CVD process in the processing target substrate in the vacuum vessel under the plasma
Can is a plasma processing method and apparatus for plasma treatment by the plasma etching method, to improve the conventional plasma processing rate while suppressing the occurrence of undesirable particulates into the plasma treatment.

[0043] subjected to amplitude modulation which is based on sine wave to the high-frequency power having a predetermined frequency for plasma processing gas
Power in a sine wave amplitude modulation
Is the basic modulation wave, and the modulation frequency is an integral multiple of the basic modulation frequency.
In applying the power in the state where the high frequency of the wave number is superimposed ,
In order to maintain the plasma even when the amplitude-modulated high-frequency power has the minimum amplitude, the dielectric constant of the plasma is stabilized, the plasma processing is performed more smoothly, the behavior of the fine particles becomes more moderate, and the electrode becomes smaller. Alternatively, the fine particles trapped in the vicinity thereof do not diffuse to the substrate to be processed, or are further transported from the trapped state to the outside of the vacuum container with evacuation.

Since the amplitude-modulated high-frequency power is in a state where a harmonic having a modulation frequency that is an integral multiple of the basic modulation frequency is superimposed on the basic modulation wave, the plasma CV
The plasma processing can be variously controlled with respect to film uniformity and film quality in film formation by D , and etching uniformity in plasma etching.

[Brief description of the drawings]

FIG. 1A shows a plasma C according to an embodiment of the present invention.
It is a figure which shows the schematic structure of the example of an apparatus which is a basic of a VD apparatus, FIG. (B) shows the example of the electric power waveform for plasma generation employ | adopted in this apparatus, FIG. FIG. 4D shows the fluctuation state of the film formation contributing reactive species under the same electric power. FIG. (E) shows another example of the amplitude modulation power supply.

FIG. 2 is a diagram showing a schematic configuration of an example of a basic apparatus of a plasma etching apparatus according to another embodiment of the present invention.

FIG. 3A shows an example of a pulse-modulated high-frequency power, FIG. 3B shows a measurement result of a frequency band in the high-frequency power, and FIG. 3C shows an amplitude-modulated high-frequency power by a sine wave. One example is shown, and FIG. (D) shows the measurement result of the frequency band under the power.

FIG. 4A shows a high-frequency power waveform in which a second harmonic is superimposed on a basic modulation wave, and FIG. 4B shows a high-frequency power waveform in which a third harmonic is superimposed on the basic modulation wave.

FIG. 5 is a schematic configuration diagram of an example of a conventional plasma CVD apparatus.

FIG. 6 is a schematic configuration diagram of an example of a conventional plasma etching apparatus.

[Explanation of symbols]

 1, 10 Vacuum container 2, 30 Ground electrode 3, 20 High frequency electrode 31, 201 Matching box 321, 203 High frequency power supply 322, 204 Amplitude modulator 323 Waveform synthesizer 324 RF amplifier 33, 301 Gas nozzle 34, 302 Plate with gas supply hole 21 Heater 51, 71 Open / close valve 52, 72 Exhaust pump 4, 6 Gas supply unit S1 Film formation target substrate S2 Etching target substrate

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-195273 (JP, A) JP-A-1-149965 (JP, A) JP-A-5-206072 (JP, A) JP-A-5-205 156451 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/205 C23C 16/50 C23F 4/00 H01L 21/3065 H05H 1/46

Claims (6)

(57) [Claims] 1. A process gas is introduced under a predetermined vacuum between opposed electrodes provided in a vacuum vessel, a power is applied to generate a plasma, and a plasma is applied to a substrate to be processed in the vacuum vessel under the plasma. Plasma treatment by plasma CVD or plasma
In the plasma processing method for performing plasma processing by an etching method, the applied plasma generation power is amplitude-modulated high-frequency power obtained by performing amplitude modulation based on a sine wave on high-frequency power of a predetermined frequency , and the power is a sine.
Integer of the fundamental modulation frequency in the fundamental modulation wave by wave amplitude modulation
Power with double harmonics superimposed
A plasma processing method characterized by the above-mentioned. 2. The plasma processing method according to claim 1, wherein said plasma can be maintained even when said amplitude-modulated high-frequency power has a minimum amplitude. 3. An amplitude-modulated high-frequency power of 13.56 M.
Hz high frequency power at least 100Hz modulation frequency
Performs amplitude modulation based on a sine wave in the range of
The plasma processing method according to claim 1 or 2 , wherein the power is in a state of being in a state of being changed . 4. A process gas is introduced under a predetermined vacuum between opposed electrodes provided in a vacuum vessel, and a power is applied to generate a plasma, and a plasma is applied to a substrate to be processed in the vacuum vessel under the plasma. In a plasma processing apparatus for performing a plasma process by a plasma CVD method or a plasma process by a plasma etching method, the means for applying the plasma generation power may be a state in which amplitude modulation based on a sine wave is performed on high frequency power of a predetermined frequency. A plasma processing apparatus characterized by applying a power of amplitude modulated high-frequency power in which a harmonic having a modulation frequency that is an integral multiple of the basic modulation frequency is superimposed on a basic modulation wave obtained by sine wave amplitude modulation. 5. The apparatus according to claim 5, wherein said power applying means is adapted to apply said amplitude
The plasma is maintained even when the modulated RF power is at the lowest amplitude.
The plasma processing apparatus according to claim 4, wherein the power is a power that can be held . 6. The power supply device according to claim 1 , wherein
The modulated high frequency power is reduced to 13.56 MHz high frequency power.
At least the modulation frequency range of 100 Hz to 1 MHz
Power in a state where amplitude modulation based on
The plasma processing apparatus according to claim 4, wherein: