JPH10284298A - Plasma processing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing method and device by which a high frequency induced type plasma can easily be produced in a high vacuum. SOLUTION: As an appropriate gas is introduced into a vacuum chamber 1 from a gas supply unit 2, air is exhausted using a pump 3, and as the inside of the vacuum chamber 1 is held at appropriate pressure, high frequency power of 100 MHz is supplied to a coil 5 by a high frequency power supply 4 for the coil; also, a direct or alternating current is passed through the coil 5 by a DC or AC power supply to produce a plasma in the vacuum chamber 1 under a high vacuum, thus making it possible 8 to perform plasma processing such as etching, accumulation, or surface reforming on a substrate 7 placed on an electrode 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method and apparatus such as dry etching, sputtering, and plasma CVD, and more particularly to a high-frequency induction type plasma processing method and apparatus.

[0002]

2. Description of the Related Art In recent years, in response to miniaturization of semiconductor devices,
In dry etching technology, in order to realize processing with a high aspect ratio, etc., and in plasma CVD technology, in order to realize embedding with a high aspect ratio, plasma processing in a higher vacuum is required. For example, in the case of dry etching, when high-density plasma is generated in a high vacuum, the probability that ions collide with neutral gas particles or the like in an ion sheath formed on the substrate surface decreases, and the direction of the ions is reduced. The properties are aligned toward the substrate and the ionization degree is high, so that the ratio of the ion flux reaching the substrate to the incident particle flux of the neutral radical is increased. Therefore, the etching anisotropy is enhanced, and processing with a high aspect ratio becomes possible. In the case of plasma CVD, when high-density plasma is generated in a high vacuum, a fine pattern is buried and flattened by the sputtering effect of ions, and burying with a high aspect ratio becomes possible.

As one of plasma processing apparatuses capable of generating high-density plasma in a high vacuum, there is a high-frequency induction type plasma processing apparatus that generates plasma in a vacuum chamber by applying a high-frequency voltage to a coil. This type of plasma processing apparatus generates a high-frequency magnetic field in a vacuum chamber, generates an induced electric field in the vacuum chamber by the high-frequency magnetic field, accelerates electrons, and generates plasma. High-density plasma can be generated even in a vacuum, and a sufficient processing speed can be obtained. FIG. 11 shows an example of a conventional high frequency induction type plasma processing apparatus. In FIG.
When the pump 3 is evacuated while introducing an appropriate gas from the gas supply means 2 into the vacuum chamber 1 and high-frequency power is supplied to the coil 5 by the coil high-frequency power supply 4 while maintaining the inside of the vacuum chamber 1 at an appropriate pressure, Plasma is generated in the vacuum chamber 1 and the substrate 7 mounted on the electrode 6 is etched.
Plasma treatment such as deposition and surface modification can be performed.
At this time, as shown in FIG. 11, by supplying high-frequency power to the electrode 6 from the electrode high-frequency power supply 11, the substrate 7
Can be controlled.

[0004]

However, FIG.
The conventional method described in (1) has a problem that plasma is hardly generated in a high vacuum of 10 mTorr or less. When a VHF band of 30 to 300 MHz is used as the frequency of the high-frequency power to lower the electron temperature of the plasma, it is particularly difficult to generate plasma. As a method for avoiding this problem, there is a method in which plasma is once generated at a pressure of 10 mTorr or more, and then the pressure is reduced. This is because once the high-frequency induction type plasma can be generated, the plasma is maintained even if the pressure is reduced to a high vacuum of 1 mTorr or less. However, in such a method, as plasma processing proceeds, reaction products and the like adhere to an exhaust system constituted by a pump or the like, particularly a valve for adjusting pressure, and it is desired to gradually increase the opening of the valve. However, there is a problem that the high vacuum is not attained, the evacuation capacity is reduced, and the time required for lowering the pressure varies.

As shown in FIG. 12, a plurality of permanent magnets 13 are provided around the vacuum chamber 1 to generate a magnetic field in the vacuum chamber 1 so that electrons can be efficiently accelerated. There is a method of generating plasma in a high vacuum. However, in this method, since the substrate 7 is always placed under a high magnetic field during the plasma processing, electrons and ions are separated in the plasma, and the substrate 7 is partially positive or negative. So-called charge-up damage that the thin insulating film formed on the substrate 7 causes electrostatic breakdown. FIG.
As shown in FIG. 3, there is a method in which a DC current is applied to the ring-shaped solenoid coil 14 to generate a magnetic field in the vacuum chamber 1 so that electrons are efficiently accelerated to generate plasma in a high vacuum. . But with this method,
In addition to the charge-up damage problem described above, there is a disadvantage that the device configuration becomes very complicated and large. An object of the present invention is to provide a plasma processing method and apparatus capable of easily generating high frequency induction type plasma in a high vacuum in view of the above-mentioned conventional problems.

[0006]

In order to achieve the above object, the present invention is configured as follows. First of the present invention
According to the aspect, the vacuum chamber is evacuated while supplying gas into the vacuum chamber, and while controlling the vacuum chamber to a predetermined pressure, high-frequency power is supplied to the coil to generate plasma in the vacuum chamber. In a plasma processing method for processing a substrate placed on an electrode in the vacuum chamber, a DC current is applied to the coil at least until plasma is generated in the vacuum chamber from a state where plasma is not generated in the vacuum chamber. A plasma processing method is characterized in that high-frequency power is supplied to the coil to generate plasma while generating a DC magnetic field in the vacuum chamber by flowing. According to a second aspect of the present invention, there is provided the plasma processing method according to the first aspect, wherein immediately after the plasma is generated in the vacuum chamber, the flow of the direct current to the coil is stopped. According to a third aspect of the present invention, there is provided the plasma processing method according to the first or second aspect, wherein the magnitude of the DC magnetic field generated in the vacuum chamber is at least 100 Gauss or more near the coil.

According to a fourth aspect of the present invention, the vacuum chamber is evacuated while supplying gas into the vacuum chamber, and high-frequency power is supplied to the coil while controlling the vacuum chamber at a predetermined pressure. In a plasma processing method of generating a plasma in the vacuum chamber and processing a substrate mounted on an electrode in the vacuum chamber, plasma is generated in at least the vacuum chamber from a state in which no plasma is generated in the vacuum chamber. A plasma processing method characterized by supplying high frequency power to the coil to generate the plasma while generating an AC magnetic field in the vacuum chamber by flowing an AC current through the coil until the generation of the plasma. According to a fifth aspect of the present invention, there is provided the plasma processing method according to the fourth aspect, wherein immediately after the plasma is generated in the vacuum chamber, the flow of the alternating current to the coil is stopped. According to a sixth aspect of the present invention, there is provided the plasma processing method according to the fourth or fifth aspect, wherein the AC frequency is less than 30 MHz. According to a seventh aspect of the present invention,
In any one of the first to sixth aspects, there is provided a plasma processing method in which the frequency of the high-frequency power supplied to the coil is 30 to 300 MHz.

According to an eighth aspect of the present invention, there is provided the plasma processing method according to any one of the first to seventh aspects, wherein the high-frequency power is supplied to the electrode. According to a ninth aspect of the present invention, an apparatus for supplying gas into a vacuum chamber, an apparatus for exhausting the vacuum chamber, an electrode for mounting a substrate in the vacuum chamber, and generating plasma in the vacuum chamber A coil for causing the device to supply high-frequency power to the coil,
By providing a device for flowing a DC current to the coil, by flowing a DC current to the coil at least until plasma is generated in the vacuum chamber from a state where plasma is not generated in the vacuum chamber, A plasma processing apparatus characterized in that high frequency power is supplied to the coil to generate plasma while generating a DC magnetic field. According to a tenth aspect of the present invention, there is provided the plasma processing apparatus according to the ninth aspect, wherein the apparatus for flowing the DC current has a function of stopping supply of the DC current at an arbitrary time.

According to an eleventh aspect of the present invention, an apparatus for supplying gas into a vacuum chamber, an apparatus for exhausting the vacuum chamber, an electrode for mounting a substrate in the vacuum chamber, A coil for generating plasma, a device for supplying high-frequency power to the coil, and a device for supplying an alternating current to the coil, and a state in which no plasma is generated in the vacuum chamber; By passing an alternating current through the coil until the occurrence of, while generating an alternating magnetic field in the vacuum chamber,
A plasma processing apparatus characterized in that high frequency power is supplied to the coil to generate the plasma.
According to a twelfth aspect of the present invention, there is provided the plasma processing apparatus according to the eleventh aspect, wherein the device for flowing an alternating current has a function of stopping supply of an alternating current at an arbitrary time. According to a thirteenth aspect of the present invention, the eleventh or twelfth aspect
In an embodiment, there is provided a plasma processing apparatus in which the frequency of the alternating current is less than 30 MHz. According to a fourteenth aspect of the present invention, there is provided the plasma processing apparatus according to any one of the ninth to thirteenth aspects, wherein the frequency of the high-frequency power is 30 to 300 MHz.

According to a fifteenth aspect of the present invention, the ninth to fourteenth aspects are provided.
In any one of the above aspects, there is provided a plasma processing apparatus including a device for supplying high-frequency power to the electrode. According to a sixteenth aspect of the present invention, there is provided the plasma processing apparatus according to any one of the ninth to fifteenth aspects, wherein a part or all of the coil has a multiple spiral shape. If a part or all of the spiral coil has a multiple spiral shape, the inductance of the spiral coil becomes extremely small, so that a plasma processing apparatus having excellent matching characteristics can be provided. In addition,
For the effect of multiple spiral coils, see T. Okumura and
I. Nakayama, “New inductively coupled plasma sour
ce using a multispiral coil ", Rev. Sci. Instrum. 6
6 (11), pp. 5262-5265, 1995.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plasma processing apparatus and method according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a plasma processing apparatus used in the first embodiment of the present invention. In FIG. 1, the above-described processing apparatus performs an exhaust operation by a pump 3 while introducing an appropriate predetermined gas from a gas supply unit 2 into a vacuum chamber 1, and maintains the inside of the vacuum chamber 1 at an appropriate pressure for a coil. By supplying high-frequency power of 100 MHz to the coil 5 on the dielectric 50 made of an insulator such as glass by the high-frequency power supply 4, plasma is generated in the vacuum chamber 1 and mounted on the electrode 6 in the vacuum chamber 1. The plasma processing such as etching, deposition, or surface modification can be performed on the placed substrate 7. The coil 5 has a configuration in which a DC current can be passed from a DC power supply 8. The DC power supply 8 has a function of stopping the supply of the DC current at an arbitrary time, for example, a desired time. A low-pass filter 9 is provided to prevent a high-frequency current from entering the DC power supply 8, and a high-pass filter 10 is provided to prevent a DC current from entering the high-frequency power supply for coil 4. An electrode high-frequency power supply 11 for supplying high-frequency power to the electrode 6 is provided so that ion energy reaching the substrate 7 can be controlled. FIG. 2 shows the first embodiment of the present invention.
FIG. 2 shows a plan view of a coil 5 used in the embodiment. In FIG. 2, the coil 5 is formed in a multiple spiral shape.

In the above-described plasma processing method, a DC current is supplied from the DC power supply 8 to the coil 5 at least until plasma is generated in the vacuum chamber 1 from a state in which no plasma is generated in the vacuum chamber 1. By flowing
While generating a DC magnetic field in the vacuum chamber 1, high-frequency power is supplied to the coil 5 from a high-frequency power source for coil 4 to generate plasma. To supply a current from a state in which plasma is not generated in the vacuum chamber 1 to at least a generation of plasma in the vacuum chamber 1, the supply of the current is time-controlled, and the generation of plasma is controlled by a photodiode. For example, when the current is detected, the current supply can be stopped. As an example, immediately after the plasma is generated in the vacuum chamber, for example, as shown in FIG.
After a second, the direct current can be stopped flowing through the coil.

As an example, a substrate 7 having a silicon oxide film having a thickness of 500 nm is placed on an electrode 6 and the gas species, its flow rate and pressure are adjusted to C ₄ F ₈ / H ₂ = 50/15 sccm, 5
It was set to mTorr. After the gas flow rate and pressure are stabilized, the high frequency power 1
000 W was supplied, and a DC current was supplied from the DC power supply 8 to the coil 5 to generate plasma in the vacuum chamber 1. The electrode 6 is connected to the electrode high-frequency power supply 11 to 1
A high frequency power of 500 W of 3.56 MHz was supplied. Approximately one second after the start of supply of high-frequency power and DC current, DC power supply 8
Was turned off to stop the supply of the direct current, but the generated plasma was maintained, the etching of the silicon oxide film on the substrate 7 progressed, and the etching was completed in 50 seconds. FIG. 3 is a time chart showing a series of processing procedures. In addition,
The DC magnetic field generated in the vacuum chamber 1 by the DC current flowing through the coil 5 was 150 gauss near the coil.

In the first embodiment, the magnitude of the DC magnetic field generated in the vacuum chamber 1 is
Although the case of 0 Gauss has been described, the magnetic field strength is not limited to this. Even if the magnitude of the DC magnetic field generated in the vacuum chamber 1 is about several gauss in the vicinity of the coil 5, some effects can be obtained.
In order to stably generate plasma at Torr or lower, 1
It is preferably at least 00 Gauss. When the charge-up damage in this process was evaluated by the antenna method, it was confirmed that no charge-up damage occurred. This is because the application of the DC magnetic field was only about 1 second. For reference, the charge-up damage was evaluated in the same manner when a DC magnetic field was constantly applied during the plasma processing, and dielectric breakdown of a thin insulating film was observed. In addition, only the coil 5 is supplied from the coil high-frequency power supply 4 without using a DC current for reference.
An experiment was conducted in which only high-frequency power was supplied, but no plasma was generated and the silicon oxide film was not etched at all.

Next, a plasma processing apparatus and method according to a second embodiment of the present invention will be described with reference to FIG. 2, FIG. 4, and FIG. FIG. 4 is a sectional view of a plasma processing apparatus used in the second embodiment of the present invention. In FIG. 4, while introducing a suitable predetermined gas from a gas supply unit 2 into a vacuum chamber 1, the pump 3 is evacuated, and a high-frequency power supply 4 for a coil of 150 MHz is maintained while maintaining a proper pressure in the vacuum chamber 1. Is supplied to the coil 5 on the dielectric 50 made of an insulator such as glass to generate plasma in the vacuum chamber 1, and the substrate 7 mounted on the electrode 6 in the vacuum chamber 1. Etching, deposition,
Alternatively, a plasma treatment such as surface modification can be performed. The coil 5 has a configuration in which a low-frequency AC current of 100 Hz can flow through the low-frequency AC power supply 12. The low-frequency AC power supply 12 has a function of stopping the supply of the low-frequency AC current at any time, for example, at a desired time. A low-pass filter 9 is provided to prevent high-frequency current from entering the low-frequency AC power supply 12, and a high-pass filter 10 is provided to prevent low-frequency AC current from entering the high-frequency coil power supply 4. I have. An electrode high-frequency power supply 11 for supplying high-frequency power to the electrode 6 is provided.
Can be controlled. As shown in FIG. 2, the coil 5 is formed in a multiple spiral shape.

In the above-described plasma processing method, the low-frequency AC power supply 12 supplies the coil 5 with a low-frequency AC power from a state where no plasma is generated in the vacuum chamber 1 until at least a plasma is generated in the vacuum chamber 1. By passing an electric current, while generating an AC magnetic field in the vacuum chamber 1,
High-frequency power is supplied to the coil 5 from the coil high-frequency power supply 4 to generate the plasma. To supply a current from a state in which plasma is not generated in the vacuum chamber 1 to at least a generation of plasma in the vacuum chamber 1, the supply of the current is time-controlled, and the generation of plasma is controlled by a photodiode. For example, when the current is detected, the current supply can be stopped. As an example, the flow of the DC current to the coil can be stopped immediately after the plasma is generated in the vacuum chamber, for example, about one second as shown in FIG.

As an example, a substrate 7 with a polycrystalline silicon film having a thickness of 300 nm is placed on the electrode 6 and the gas species, its flow rate and pressure are adjusted to Cl ₂ / O ₂ = 50/3 sccm, 3 m
Set to Torr. After the gas flow and pressure are stabilized,
High frequency power 800 from coil high frequency power supply 4 to coil 5
W, and a low-frequency AC power supply 12
, A plasma was generated in the vacuum chamber 1. The electrode 6 has a high frequency power supply 11 to 6 for the electrode.
40 kHz high frequency power of 00 kHz was supplied. About one second after the start of the supply of the high-frequency power and the low-frequency AC current, the low-frequency AC power supply 12 was turned off to stop the supply of the low-frequency AC current, but the generated plasma was maintained and the polycrystalline silicon film on the substrate 7 was maintained. The etching progressed, and the etching was completed in 60 seconds. FIG. 5 is a time chart showing a series of processing procedures. The instantaneous maximum value of the low-frequency AC magnetic field generated in the vacuum chamber 1 by the low-frequency AC current flowing through the coil 5 was 100 gauss near the coil.

When the charge-up damage in this process was evaluated by the antenna method, it was confirmed that no charge-up damage occurred. This is because the application of the low-frequency AC magnetic field was only about one second. For reference, when the charge-up damage was evaluated by the same method when a low-frequency AC magnetic field was constantly applied during the plasma processing, dielectric breakdown of a thin insulating film was observed. For reference, an experiment was also conducted in which only high-frequency power was supplied from the coil high-frequency power supply 4 to the coil 5 without using an alternating current. However, no plasma was generated and the polycrystalline silicon film was not etched at all. Was.

Next, a plasma processing apparatus and method according to a third embodiment of the present invention will be described with reference to FIG. 2, FIG. 6, and FIG. FIG. 6 shows a sectional view of a plasma processing apparatus used in the third embodiment of the present invention. In FIG. 6, the pump 3 is evacuated while an appropriate predetermined gas is introduced from the gas supply unit 2 into the vacuum chamber 1, and the high-frequency power supply 4 for the coil is operated at 150 MHz while maintaining the inside of the vacuum chamber 1 at an appropriate pressure. Is supplied to the coil 5 on the dielectric 50 made of an insulator such as glass to generate plasma in the vacuum chamber 1, and the substrate 7 mounted on the electrode 6 in the vacuum chamber 1. Etching, deposition,
Alternatively, a plasma treatment such as surface modification can be performed. The coil 5 is configured so that a high-frequency AC current of 13.56 MHz can flow through the high-frequency AC power supply 32. The high-frequency AC power supply 32 has a function of stopping the supply of the high-frequency AC current at any time, for example, at a desired time. 13.56 MHz
A low-pass filter 39 is provided to prevent a high-frequency current of 150 MHz from entering the high-frequency AC power supply 32 of FIG.
A high-pass filter 40 is provided to prevent a high-frequency AC current of 3.56 MHz from entering. High frequency power supply for electrode 11 for supplying high frequency power to electrode 6
Is provided, so that the ion energy reaching the substrate 7 can be controlled. Coil 5
Is composed of multiple spirals as shown in FIG.

In the above-described plasma processing method, the high-frequency AC power supply 32 supplies the coil 5 with the AC current from the state where no plasma is generated in the vacuum chamber 1 until at least the plasma is generated in the vacuum chamber 1. To generate an AC magnetic field in the vacuum chamber 1,
High-frequency power is supplied to the coil 5 from the coil high-frequency power supply 4 to generate the plasma. To supply a current from a state in which plasma is not generated in the vacuum chamber 1 to at least a generation of plasma in the vacuum chamber 1, the supply of the current is time-controlled, and the generation of plasma is controlled by a photodiode. For example, when the current is detected, the current supply can be stopped. For example, the flow of the DC current to the coil can be stopped immediately after the plasma is generated in the vacuum chamber, for example, about one second as shown in FIG.

As an example, a substrate 7 having a polycrystalline silicon film having a thickness of 300 nm is placed on the electrode 6 and the gas species, its flow rate and pressure are adjusted to Cl ₂ / O ₂ = 50/3 sccm, 3 m
Set to Torr. After the gas flow and pressure are stabilized,
High frequency power 800 from coil high frequency power supply 4 to coil 5
W, and a high-frequency AC power supply 32
, A plasma was generated in the vacuum chamber 1. The electrode 6 has a high frequency power supply 11 to 6 for the electrode.
40 kHz high frequency power of 00 kHz was supplied. About one second after the start of the supply of the high-frequency power and the high-frequency AC current, the high-frequency AC power supply 32 was turned off to stop the supply of the high-frequency AC current. However, the generated plasma was maintained, and the etching of the polycrystalline silicon film on the substrate 7 was stopped. The etching progressed, and the etching was completed in 60 seconds. FIG. 7 is a time chart showing a series of processing procedures.

When the charge-up damage in this process was evaluated by the antenna method, it was confirmed that no charge-up damage occurred. The charge-up damage was evaluated by the same method when a high-frequency AC magnetic field was constantly applied during the plasma processing, but no dielectric breakdown of the thin insulating film was observed.
This is because electrons and ions are not separated in the plasma because the frequency of the applied high-frequency AC magnetic field is sufficiently high that ions cannot follow. However, when a high-frequency AC magnetic field was constantly applied during the plasma processing, the electron temperature of the plasma increased, and a vertical etching shape could not be obtained. For reference, an experiment was also conducted in which only high-frequency power was supplied from the coil high-frequency power supply 4 to the coil 5 without using an alternating current. However, no plasma was generated and the polycrystalline silicon film was not etched at all. Was.

In the first to third embodiments of the present invention described above, the frequency of the high-frequency power supplied to the coil 5 is 100M
Hz and 150 MHz.
The frequency is not limited to this, and is 1 MHz to 3 MHz.
At a frequency of about 00 MHz, the plasma processing method and apparatus of the present invention are effective. In particular, 30 to 300 MH
In the plasma processing method and apparatus using the VHF band of z, excellent effects can be obtained. In the second embodiment, when selecting the frequency of the high-frequency power supplied to the coil 5 from a range of 1 MHz to 300 MHz,
The frequency of the high-frequency power is set higher than the frequency of the AC of the low-frequency AC power supply 12. In the second and third embodiments of the present invention described above, the frequency of the low-frequency AC is 100H.
z, and the case where the frequency of the high-frequency AC is 13.56 MHz has been described.
Since the discharge is difficult in the above, any frequency may be used as long as it is generally less than 30 MHz. Further, in the embodiment of the present invention described above, the etching of the silicon oxide film and the etching of the polycrystalline silicon film have been described.
Needless to say, the present invention can be applied to other plasma processing such as etching, sputtering, or CVD.

In the embodiment of the present invention described above,
Although the case where the multiple planar spiral coils are mounted along the outer wall surface of the vacuum chamber has been described, it is needless to say that the shape of the coil and the positional relationship between the vacuum chamber and the coil are limited to this. However, the present invention can be applied to all types of high-frequency induction type plasma processing methods and apparatuses, including other modes as shown in FIGS. Here, the coil 5 of FIG. 8 is configured by a single spiral coil 5a, the coil of FIG. 9 is configured by a coil 5b wound around the side surface of the vacuum chamber 1, and the coil of FIG. It is composed of a dome-shaped spiral coil 5c disposed on a dielectric 50c such as a dome-shaped insulator made of glass. Further, in the embodiment of the present invention described above, the case where the application of the direct current or the low frequency or the high frequency alternating current is stopped in about 1 second has been described. Needless to say, in order to further prevent the charge-up damage, it is necessary to stop the application of the DC current or the low-frequency or high-frequency AC current immediately after the plasma is generated. desirable. Further, as shown in FIG. 2, the location where the DC or AC is supplied from the DC or AC power supplies 8, 12, 32 to the coil 5 is not limited to the center of the coil 5 but may be a predetermined location around the coil 5. However, if DC or AC is supplied to the center of the coil 5, there is an advantage that plasma is easily generated.

[0025]

As is clear from the above description, according to the plasma processing method of the present invention, the vacuum chamber is evacuated while supplying gas into the vacuum chamber, and the vacuum chamber is controlled to an appropriate predetermined pressure. In a plasma processing method for generating plasma in a vacuum chamber by supplying high-frequency power to a coil and processing a substrate mounted on an electrode in the vacuum chamber, from a state in which plasma is not generated in the vacuum chamber, A DC magnetic field is generated in the vacuum chamber by flowing a DC current through the coil at least until plasma is generated in the vacuum chamber, so that high-frequency induction-type plasma can be easily generated in a high vacuum. Further, according to the plasma processing method of the present invention, by evacuating the vacuum chamber while supplying gas into the vacuum chamber, and supplying high frequency power to the coil while controlling the vacuum chamber to an appropriate predetermined pressure,
In a plasma processing method of generating plasma in a vacuum chamber and processing a substrate mounted on an electrode in the vacuum chamber, a state in which plasma is not generated in the vacuum chamber until at least plasma is generated in the vacuum chamber. By supplying an alternating current to the coil, it is possible to easily generate a high frequency induction type plasma in a high vacuum.

According to the plasma processing apparatus of the present invention, an apparatus for supplying gas into the vacuum chamber, an apparatus for exhausting the vacuum chamber, an electrode for placing a substrate in the vacuum chamber,
Since a coil for generating plasma in a vacuum chamber, a device for supplying high-frequency power to the coil, and a device for passing DC current to the coil are provided, it is possible to easily generate high-frequency induction plasma in a high vacuum. it can. Further, according to the plasma processing apparatus of the present invention, an apparatus for supplying gas into the vacuum chamber, an apparatus for exhausting the vacuum chamber, an electrode for mounting a substrate in the vacuum chamber, and a plasma for generating plasma in the vacuum chamber. , A device for supplying high-frequency power to the coil, and a device for supplying alternating current to the coil, it is possible to easily generate high-frequency induction type plasma in a high vacuum.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a plasma processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a coil according to first, second, and third embodiments of the present invention. For the sake of simplicity, FIG. 2 omits a DC or AC power supply and various filters.

FIG. 3 is a time chart showing a series of processing procedures in the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of a plasma processing apparatus according to a second embodiment of the present invention.

FIG. 5 is a time chart showing a series of processing procedures in a second embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of a plasma processing apparatus according to a third embodiment of the present invention.

FIG. 7 is a time chart showing a series of processing procedures in a third embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a plasma processing apparatus according to another embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a plasma processing apparatus according to another embodiment of the present invention.

FIG. 10 is a diagram showing a configuration of a plasma processing apparatus according to another embodiment of the present invention.

FIG. 11 is a cross-sectional view illustrating a configuration of a plasma processing apparatus used in a conventional example.

FIG. 12 is a cross-sectional view illustrating a configuration of a plasma processing apparatus used in a conventional example.

FIG. 13 is a sectional view showing a configuration of a plasma processing apparatus used in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Gas supply unit 3 Pump 4 High frequency power supply for coil 5, 5a, 5b, 5c Coil 6 Electrode 7 Substrate 8 DC power supply 9 Low pass filter 10 High pass filter 11 High frequency power supply for electrode 12 Low frequency AC power supply 32 High frequency AC power supply 50 Dielectric

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/205 H01L 21/205 21/3065 21/302 A

Claims (16)

[Claims] The vacuum chamber is evacuated while supplying gas into the vacuum chamber, and high-frequency power is supplied to a coil while controlling the vacuum chamber at a predetermined pressure. A plasma processing method for processing a substrate (7) mounted on an electrode (6) in the vacuum chamber by generating plasma in the chamber, wherein at least the vacuum chamber is changed from a state in which no plasma is generated in the vacuum chamber. A plasma processing method comprising supplying a high-frequency power to the coil while generating a DC magnetic field in the vacuum chamber by flowing a DC current through the coil until plasma is generated, to generate plasma. 2. After the plasma is generated in the vacuum chamber,
2. The plasma processing method according to claim 1, wherein the flow of the direct current to the coil is stopped immediately. 3. The magnitude of the DC magnetic field generated in the vacuum chamber is at least 100 in the vicinity of the coil.
3. The plasma processing method according to claim 1, wherein the plasma processing method is Gauss or more. 4. The above-mentioned vacuum chamber is evacuated while supplying gas into the vacuum chamber (1), and a high-frequency power is supplied to the coil (5) while controlling the vacuum chamber at a predetermined pressure. In a plasma processing method for generating plasma in a vacuum chamber and processing a substrate (7) mounted on an electrode (6) in the vacuum chamber, at least the vacuum chamber is changed from a state in which no plasma is generated in the vacuum chamber. A plasma process in which an alternating current is passed through the coil until plasma is generated, thereby generating an alternating magnetic field in the vacuum chamber and supplying high-frequency power to the coil to generate the plasma. Method. 5. After the plasma is generated in the vacuum chamber,
The plasma processing method according to claim 4, wherein the flow of the alternating current to the coil is stopped immediately. 6. The plasma processing method according to claim 4, wherein the frequency of the alternating current is less than 30 MHz. 7. The plasma processing method according to claim 1, wherein the frequency of the high-frequency power supplied to the coil is 30 to 300 MHz. 8. The plasma processing method according to claim 1, wherein high-frequency power is supplied to said electrode. 9. An apparatus (2) for supplying gas into a vacuum chamber (1), an apparatus (3) for evacuating the vacuum chamber, and an electrode (10) for mounting a substrate (7) in the vacuum chamber. 6)
A coil (5) for generating plasma in the vacuum chamber, a device (4) for supplying high-frequency power to the coil, and a device (8) for flowing a direct current to the coil, By supplying a DC current to the coil at least until plasma is generated in the vacuum chamber from a state in which no plasma is generated in the vacuum chamber, high-frequency power is supplied to the coil while generating a DC magnetic field in the vacuum chamber. A plasma processing apparatus for generating plasma. 10. The plasma processing apparatus according to claim 9, wherein the DC current flowing device has a function of stopping supply of the DC current at an arbitrary time. 11. A device (2) for supplying gas into a vacuum chamber (1), a device (3) for evacuating the vacuum chamber, and an electrode (11) for mounting a substrate (7) in the vacuum chamber. 6)
A coil (5) for generating plasma in the vacuum chamber, a device (4) for supplying high-frequency power to the coil, and a device (12, 32) for supplying an alternating current to the coil. By applying an alternating current to the coil at least until plasma is generated in the vacuum chamber from a state where plasma is not generated in the chamber, high-frequency power is applied to the coil while generating an AC magnetic field in the vacuum chamber. A plasma processing apparatus, wherein the plasma is supplied to generate the plasma. 12. The plasma processing apparatus according to claim 11, wherein the device for flowing the alternating current has a function of stopping the supply of the alternating current at an arbitrary time. 13. The plasma processing apparatus according to claim 11, wherein the frequency of the alternating current is less than 30 MHz. 14. The frequency of the high frequency power is 30 to 30.
The plasma processing apparatus according to claim 9, wherein the frequency is 0 MHz. 15. The plasma processing apparatus according to claim 9, further comprising a device (11) for supplying high-frequency power to said electrodes. 16. The plasma processing apparatus according to claim 9, wherein a part or all of the coil has a multiple spiral shape.