JP2001271168A - Surface treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treating device with which surface treatment can be performed at a high speed and also in high quality. SOLUTION: In a casing (2) of this surface treating device (1), a plate (6) is installed between a plasma generating region (3) and a substrate supporting stand (9). The plate (6) functions also as an anode electrode which generates plasma. A plasma blow-off hole (7) is formed in the plate (6), and at the hole (7) hollow anode plasma discharge is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment apparatus suitable for various surface treatments on a substrate, and more particularly, to a surface treatment apparatus suitable for film formation on a substrate. The present invention relates to a surface treatment apparatus capable of performing the following.

[0002]

2. Description of the Related Art Conventionally, a surface treatment apparatus for applying a high-frequency power to a parallel plate electrode to convert a reaction gas into a plasma state and decompose it into chemically active ions and radicals to perform surface treatment such as etching and film formation. It has been known.

For example, a conventional parallel plate type plasma CVD (Chemical Vapor Deposition) apparatus for performing a film forming process is as follows.
A pair of flat plate-like plasma generating electrodes are provided in the casing so as to face in parallel. One of the plasma generating electrodes also has a function as a substrate support, and further, the device is provided with a heater to adjust the temperature of the substrate to a temperature suitable for vapor phase growth. . When a high-frequency power source (13.56 MHz power source) is applied between the two plasma generating electrodes while the substrate is placed on the one electrode, plasma is generated between the electrodes and the source gas, For example, a monosilane gas is activated, and a silicon film is formed on the substrate surface.

[0004] Such conventional parallel plate type plasma CVD.
The apparatus has an advantage that a large-area substrate can be formed by a single film-forming process by increasing the area of the plate-shaped plasma generating electrode on which the substrate is placed. . However, in the conventional parallel plate type plasma CVD apparatus, the source gas converted into plasma by both plasma generating electrodes is uniformly diffused into the film forming gas processing chamber, and a part thereof is placed on the electrode. It only contributes to the deposition of the substrate. For this reason, the utilization efficiency of the source gas is low. For example, when an amorphous silicon thin film or a crystalline silicon thin film is to be formed on a substrate, the film forming speed is 1 to 1.
Despite the large input power of about 2Å / sec.
The deposition rate is slow. Therefore, it takes a longer time to manufacture a semiconductor device having a relatively large thickness such as a solar cell, which has been a main factor of low throughput and high cost.

Therefore, it is conceivable to increase the power supplied by the high-frequency power supply in order to increase the film forming speed. However, by increasing the input power, the energy of the charged particles in the plasma increases. Damage caused by the collision of the charged particles having high energy with the substrate degrades the film quality of the substrate. Further, with the increase of the high frequency power by the high frequency power source, a large amount of fine powder is generated in the gas phase, and the deterioration of the film quality due to the fine powder also increases dramatically.

Accordingly, a conventional parallel plate type plasma CV
In the case of the D apparatus, the input power must be reduced in order to avoid damage due to collision of charged particles of high energy and deterioration of the film quality due to fine powder. That is, the upper limit of the input power substantially exists, and the film formation rate cannot be increased to a certain level or more.

Further, in a parallel plate type plasma etching apparatus, since the deterioration of the processing quality due to the increase of the input power is smaller than that of the film forming process, it is necessary to increase the input power to increase the processing speed to some extent. Can be. However, for the purpose of improving the quality of the etching process, improving the manufacturing efficiency, and reducing the manufacturing cost, it is presently desired to further improve the processing speed.

On the other hand, Japanese Patent Application Laid-Open No. 11-145492 discloses
The apparatus for forming a photovoltaic element on a belt-shaped member, which is a moving object to be processed, disclosed in Japanese Patent Application Laid-Open Publication No. H11-146, discloses a method in which the surface area of a high-frequency power application electrode (cathode electrode) in a discharge space is reduced to the entire anode electrode including the belt-shaped member. And the surface potential of the cathode electrode when a glow discharge occurs is maintained at a positive potential of +30 V or more with respect to the grounded anode electrode including the belt-shaped member. Further, a plurality of threshold electrodes are provided on the cathode electrode at right angles to the running direction of the belt-shaped member, and discharge is generated between adjacent threshold electrodes. As described above, the cathode electrode is maintained at a positive potential of +30 V or more with respect to the strip-shaped member and the anode electrode, and the cathode electrode structure having the cut-off electrodes as described above is used. It promotes the excitation and decomposition reaction of material gas.

It is considered that the film forming rate of the photovoltaic device forming apparatus disclosed in the above publication is certainly improved by promoting the excitation and decomposition reaction of the material gas on the anode electrode side including the belt-shaped member. However, since glow discharge is also generated in the space between the belt-shaped member and the cathode electrode, damage due to collision of charged particles is still unavoidable.

Therefore, for example, a thin film forming apparatus disclosed in Japanese Patent Application Laid-Open No. 61-32417 comprises a definition chamber having a pair of opposed plasma generating electrodes in a vacuum chamber for forming a thin film on a substrate. An activation gas generator is provided. A single pore is formed in one wall of the activation gas generator for ejecting the activation gas into the vacuum chamber. A substrate is supported in the vacuum chamber at a position facing the pores.

In the thin film forming apparatus, high frequency power is applied to the pair of plasma generating electrodes to generate a glow discharge between the two electrodes to generate plasma. The source gas introduced into the activated gas generator is decomposed by the plasma. At this time, by adjusting the vacuum pump disposed in the vacuum chamber and the conductance of the pore, the degree of vacuum in the vacuum chamber is set to be 2-3 times higher than in the activated gas generator.
The activated source gas is ejected from the pores toward the substrate so as to have an order of magnitude lower.

A plasma generating electrode is arranged inside an activated gas generator defined in a vacuum chamber for forming a thin film as described above, and the raw material gas activated in the activated gas generator is directed toward a substrate. In the thin film forming apparatus that actively sprays, the film forming speed can be increased without increasing the input power. Furthermore, even when the input power is increased to generate stronger plasma, the plasma generating electrode is installed in the defined activated gas generator, and the substrate is generated by glow discharge between the electrodes. There is no danger of damaging the surface. Therefore, it is possible to further increase the film forming speed by increasing the input power. In addition, crystallization of the thin film is promoted in spite of an increase in the film forming rate, and a high-quality thin film can be formed at a film forming rate higher than that in the related art.

[0013]

As described above, although the deposition rate is increased by defining the plasma generation chamber and the deposition processing chamber, it is desired to further improve the deposition rate. In particular, high-speed deposition of a microcrystalline thin film is strongly desired for use in solar cells and the like. Furthermore, since it is divided into two chambers, the internal structure of the surface treatment apparatus becomes complicated, and a large vacuum pump is required to generate a pressure difference between the two chambers, so that the manufacturing cost is increased. There is also a problem that soaring. Accordingly, an object of the present invention is to provide a surface treatment apparatus capable of performing surface treatment at higher speed and with higher quality and reducing manufacturing cost in order to achieve such a demand.

[0014]

Means for Solving the Problems and Effects of the Invention In order to solve the above problems, the invention according to claim 1 is directed to a plasma generating means, a raw material gas inlet, and a casing provided with a substrate support. What is claimed is: 1. A surface processing apparatus for generating a plasma by a generating means to convert a raw material gas into a plasma, and performing a plasma process on a surface of a substrate mounted on the substrate support table, wherein the plasma generating region including the plasma generating means and the substrate A plate member having one or more plasma outlets is interposed between the substrate processing region having the support table and at least one plate member has one or more hollow discharge generation regions. It is characterized by.

Further, the invention according to claim 2 provides a method for generating a plasma by means of the plasma generating means in a casing provided with a plasma generating means, a raw material gas inlet, and a substrate support, to convert the raw material gas into plasma. What is claimed is: 1. A surface processing apparatus for performing plasma processing on a surface of a substrate placed on a substrate support, comprising: a plasma processing area provided with the plasma generating means; and a substrate processing area provided with the substrate support. A plate member having the above-described plasma outlet is interposed, and a hollow plasma generation electrode having one or more hollow discharge generation regions is arranged in the plasma generation region.

According to a third aspect of the present invention, a plasma is generated by the plasma generating means in a casing having a plasma generating means, a raw material gas inlet, and a substrate support, and the raw material gas is turned into plasma. A surface processing apparatus for performing plasma processing on a surface of a substrate mounted on the substrate support, wherein the casing includes a plasma generation area including the plasma generation unit and a substrate processing area including the substrate support. A plate member having one or more plasma outlets is interposed therebetween, and at least one plate member has one or more hollow discharge generation regions, and the plasma generation region has one or more hollow discharge generation regions. And a hollow plasma generating electrode having the following characteristics.

In the present invention, the term "hollow discharge" refers to a phenomenon in which plasma, which is particularly observed in through holes, concave portions, and hollow portions, is strongly generated and the density of the plasma is increased.
As the plasma generation means, discharge by a pair of plasma generation electrodes consisting of a cathode and an anode, discharge having three or more electrodes, microwave discharge, capacitively-coupled discharge,
Means such as inductively coupled discharge, helicon wave discharge, PIG discharge, and electron beam excited discharge can be employed.

According to the first and third aspects of the present invention, the hollow discharge generated in the plate member interposed between the plasma generation region and the substrate processing region depends on the potential of the hollow discharge generation region of the plate member. It becomes hollow cathode discharge or hollow anode discharge.

For example, when a pair of plasma generating electrodes composed of a cathode and an anode is used as the plasma generating means, any one of the electrodes can be used as the plate member. When an anode electrode is used as the plate member, a discharge generated in a hollow discharge generation region formed on the anode electrode is a hollow anode discharge. Further, when the cathode electrode is used as a plate member, the discharge generated in the hollow discharge generation area is a hollow cathode discharge.
In this specification, an electrode on the side to which main power for discharging is applied is a cathode electrode, and an electrode facing the cathode electrode is an anode electrode.

In particular, since the plasma discharge port formed in the plate member is used as a hollow discharge generation region, the density of plasma introduced into the substrate processing region can be increased more effectively. ,preferable. Alternatively, a plate member may be interposed in two regions separately from a pair of plasma generation electrodes serving as plasma generation means, and a plasma outlet may be formed in the plate member.

In the invention according to claims 2 and 3, when a pair of plasma generating electrodes including a cathode and an anode is adopted as the plasma generating means, at least one of the plasma generating electrodes is connected to the hollow. It can also be used as a plasma generating electrode. Alternatively, the hollow plasma generating electrode can be provided as a third electrode separately from the plasma generating electrode.

The surface treatment apparatus of the present invention as described above
What is necessary is just to interpose a plate member between the plasma generation region and the substrate processing region in the casing, and it is not necessary to completely define two regions by the plate member. Therefore, the structure of the device is simplified, and the manufacturing cost of the device can be reduced.

Further, it is possible to apply a required potential to the plate member, and it is possible to more efficiently generate a hollow discharge in a hollow discharge generating area of the plate member, for example, a plasma outlet. Further, means for applying a required potential to the plate member can be easily installed.

In particular, when a pair of plasma generating electrodes is employed as the plasma generating means and the plate member is used as one pole of the plasma generating electrode, the plate member can be brought into contact with and separated from an opposing electrode. As described above, the contact / separation means can be provided. If the plate member is made to be able to contact and separate from the opposing electrode in this way, for example, depending on the applied power and other surface treatment conditions, the distance between the plate member and the opposing electrode, that is, between the plasma generating electrodes The distance can be adjusted appropriately. Thereby,
By adjusting the intensity of the discharge between the plasma generating electrodes, the processing speed and the processing quality can be controlled to desired levels.

In order to perform surface treatment by the above-mentioned surface treatment apparatus, first, a raw material gas and a carrier gas are injected into a casing through a gas supply pipe, and plasma is generated in a plasma generation region by a plasma generation means. Here, in the surface treatment device of the present invention, a plate member is interposed between the plasma generation region and the substrate treatment region. However, each region is designed to be completely partitioned as in the conventional device. Not done. As described above, in the present invention, only the plate member is interposed between the two regions, and the two regions are not completely defined. Therefore, the two regions are completely defined. Although the gas use efficiency is slightly lower than in the case, the gas can be kept in the plasma generation region by the plate member interposed between the two regions, so that the plasma can be relatively efficiently converted. It is possible.

The plasma generated in the plasma generation region flows from the plasma outlet to the substrate processing region due to the flow and diffusion of internal gas due to exhaust from the substrate processing region. At this time, by providing appropriate gas flow rates and plasma parameters, plasma in the plasma generation region is smoothly transported from the plasma outlet to the substrate processing region. Further, by interposing a plate member between the plasma generation region and the substrate processing region, ion damage to the substrate due to plasma can be reduced.

The source gas can be introduced before the plasma generated in the plasma generation region blows out to the substrate processing region and reaches the substrate surface. The activated source gas in the plasma reaches the substrate surface in the processing region by the flow of the plasma, and the substrate is subjected to surface treatment such as etching and film formation.

In the invention according to the first aspect of the present invention, it is important to generate a hollow discharge in one or more hollow discharge generating areas of the plate member. Since the plasma is newly generated in the hollow discharge generation region of the plate member by the hollow discharge, the density of the plasma guided to the substrate processing region is increased.

In particular, when the plasma discharge port formed in the plate member is used as a hollow discharge generation area, the plasma generated in the plasma generation area passes through the plasma discharge port where the hollow discharge is generated. In addition, the energy of charged particles (electrons or ions) in the plasma decreases due to the interaction due to collision or the like. Due to the decrease in the energy of the electrons, the electrons are sufficient to generate neutral active species that contribute to the surface treatment from the raw material gas, and the ions that cause damage by colliding with the substrate surface are less likely to be generated. Since the energy is strong, the number of neutral active species can be increased without increasing the number of ions. Also, by reducing the number of high energy ions in the plasma, the effect of these ions on substrate damage can be reduced.

As described above, since the hollow discharge increases the plasma density and increases the number of neutral active species contributing to the surface treatment, the speed of the surface treatment is increased. In addition, by lowering the energy of ions present in the plasma that collide with and damage the substrate, deterioration of the substrate surface can be suppressed, and high-quality surface treatment can be performed at high speed.

In the invention according to the second aspect of the present invention, it is important to arrange a hollow plasma generation electrode in the plasma generation region. For example, when a pair of plasma generating electrodes including an anode and a cathode is adopted as the plasma generating means, at least one of them can be used as a hollow plasma generating electrode. That is, it is necessary that a hollow anode discharge is generated at the anode electrode, a hollow cathode electrode is generated at the cathode electrode, or a hollow discharge is generated at both electrodes. By generating the hollow discharge, plasma is newly generated in the hollow discharge generation region, the density of plasma guided to the substrate processing region increases, and active species contributing to surface treatment increase. The speed of the surface treatment is further increased.

Further, in the invention according to claim 3,
Both the hollow discharge in the hollow discharge generation region of the plate member and the hollow discharge in the hollow plasma generation electrode are generated. For this reason, the hollow discharge at the plate member and the hollow discharge at the hollow plasma generating electrode have both the above-described effects, and the speed and quality of the surface treatment can be further improved.

Further, not only the hollow discharge at the plate member but also the hollow discharge at the hollow plasma generating electrode is generated, so that in addition to the above-described functions and effects of the respective discharges, the following synergistic functions and effects are obtained. It is obtained. That is, in addition to the hollow discharge in the plate member, the hollow plasma is generated in the hollow plasma generating electrode, so that the electron temperature in the hollow discharge region at the electrode is lowered and the electron density is increased. improves. Furthermore, for example, when the cathode electrode is a hollow plasma generating electrode and a hollow discharge occurs at the cathode electrode, the high-frequency voltage at the cathode electrode decreases and the self-bias voltage increases, so that the self-bias voltage increases in the plasma generating region. The space potential of the plasma also increases. As a result, hollow discharge easily occurs in the plate member, and high-density plasma can be generated in the plate member. Further, for the same reason, electric field concentration is likely to occur in the plasma generation region, and it is possible to generate a non-uniform discharge in which a high-density plasma is locally generated.

As the electrode material of the hollow plasma generating electrode, when a pair of plasma generating electrodes is used as the plasma generating means, the electrode material is SU.
In addition to S and Al, Ni, Si, Mo, W, and the like can be adopted. When an electrode material having a large secondary ion emission coefficient due to ion bombardment from the plasma is used, the density of the plasma becomes higher and the processing speed is improved. In particular, in the case of a surface treatment apparatus that performs a film forming process of silicon, when Si is used as an electrode material, the electrode itself functions as a supply source of a thin film material, so that the film forming speed is improved and the electrode is used. Stability also increases. Furthermore, if the electrode made of Si is doped with boron or phosphorus in advance,
It is possible to automatically dope the thin film,
This is particularly advantageous when a very small amount of doping is performed.

As the substrate, glass, an organic film,
Alternatively, a metal such as SUS can be used. Furthermore, the surface treatment apparatus of the present invention can be used for various surface treatments such as film formation, ashing, etching, and ion doping.However, a silicon thin film or an oxide film such as amorphous silicon or even crystalline silicon is formed on the substrate surface. It is particularly preferably used in such a case.

When a large number of plasma outlets are provided,
In particular, it is preferable to generate a hollow discharge using all the outlets as a hollow discharge generating region, since a uniform thin film can be formed at a high speed even on a substrate having a large area.

The source gas inlet may be open to the plasma generation region, or only the carrier gas may be introduced to the plasma generation region, and the source gas inlet may be open to the side of the plasma outlet. It can also be done. Further, using, for example, an introducing means such as a pipe for introducing a source gas, the source gas inlet is opened in the substrate processing region, and the source gas is introduced between the plasma outlet and the substrate in the substrate processing region. You may. When the source gas inlet is opened at the outlet or at the substrate processing region, the source gas is turned into plasma by a carrier gas that is turned into plasma and passes through the outlet. In this case, the inner wall surface of the plasma generation region is not contaminated by the source gas.

Although a DC power supply or a high-frequency power supply can be connected to the plasma generating electrode to apply DC to high-frequency power, it is particularly preferable to supply high-frequency power. Further, a bias may be applied to the cathode electrode and the anode electrode by a DC or AC power supply or a pulse generation power supply, respectively.

In order to generate a hollow discharge at the plasma outlet, the opening width W (1) of the minimum portion of at least one of the plasma outlets is set to W (1) ≦ 5L. (e) or W (1) ≦ 20X. However, L (e) is the atom having the smallest diameter or the molecular species (active species) among the raw gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. seed)
And X is the thickness of the sheath layer generated under the desired plasma generation conditions. Further, the opening width W (1) of the minimum portion in at least one of the plasma outlets also satisfies X / 20 ≦ W (1), and further satisfies X / 5 ≦ W (1). It is preferable to set the range.

The mean free path of electrons in the scattering of electrons and gas molecules (including atoms) depends on the gas pressure, the scattering cross section of atoms / molecules, and the temperature. Gas pressure, atom / molecule scattering cross section,
And temperature.

By setting the opening width W (1) of the plasma outlet to the above range, a hollow discharge can be effectively generated in the plasma outlet, and plasma can be efficiently generated from the outlet. Can be blown out.

In the present invention, the opening width W (1) of the plasma outlet is a diameter when the opening shape of the plasma outlet is circular, and a short side when the opening shape of the plasma outlet is rectangular or slit. Is the length dimension. That is, the shortest dimension portion in the opening shape is defined as the opening width W (1).

As the shape of the plasma outlet, it is possible to adopt a shape capable of actively drawing the plasma in the plasma generation region into the outlet and diffusing the plasma at a desired angle in the substrate processing region and ejecting the plasma. . For example, a columnar shape with a circular cross section, a frustoconical shape that expands in diameter from the plasma generation region toward the substrate processing region, and a combination thereof, and furthermore, a substantially half of the upstream side is reduced in diameter toward the downstream side, and the downstream side is reduced in diameter. And the like, in which a half portion on the side expands in diameter toward the downstream side. Further, as described above, the cross section may be a rectangular prism, or a slit may be used.

In the case where the surface treatment is performed over a wide area of the substrate, a plurality of, for example, circular plasma outlets can be formed in a required pattern. Or,
Substantially continuous long slit shape that can be written with one stroke,
Specifically, the shape may be a spiral shape or a meandering shape.

According to the fifth aspect of the present invention, the hollow plasma generating electrode has one or more concave portions on the surface facing the plasma generated by the plasma generating means,
At least one of the concave portions is a region where hollow discharge occurs. According to the invention of claim 6, the hollow plasma generating electrode is a hollow body, and the electrode has at least one through hole communicating with the inside of the hollow at a portion facing the plasma generated by the plasma generating means. And at least one of the through holes is a region where hollow discharge is generated.

As described above, a concave portion is formed in the hollow plasma generating electrode, or a through hole communicating with the hollow plasma generating electrode is formed by using the hollow plasma generating electrode as a hollow body. By setting the generation area, the surface area of the hollow plasma generation electrode substantially in contact with the plasma increases. For example, when the cathode electrode is a hollow plasma generating electrode and a cathode discharge region is formed in the cathode electrode, the potential (self-bias) of the cathode electrode at the time of glow discharge generation can be taken in a positive direction, and grounding can be performed. Consumption of input power in the vicinity of the anode electrode,
The decomposition reaction can be accelerated, and the speed of the surface treatment can be improved.

The control of the self-bias leads to the control of the plasma space potential, and the magnitude of the damage caused by the collision of the ions with the substrate can be adjusted intentionally. Therefore, for example, when performing a film forming process, the crystallinity of the crystalline thin film can be controlled.

In order to effectively generate a hollow discharge in the concave portion or the through hole, the opening width W (2) of the minimum portion in the concave portion or the through hole is set to W ( 2) The range is set so as to satisfy either ≦ 5L (e) or W (2) ≦ 20X. Where L (e)
Is the average of the electrons for the atom having the smallest diameter or the molecular species (active species) of the source gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. It is a free path, and X is the thickness of the sheath layer generated under desired plasma generation conditions.

The cross-sectional shape of the recess or the through-hole can be circular or polygonal, and the shortest dimension in the opening shape is the opening width W (2). Further, the opening width W (2) of the minimum portion of at least one of the plasma outlets satisfies X / 20 ≦ W (2), and further satisfies X / 5 ≦ W (2). It is preferable to set the range.

According to the eighth aspect of the present invention, the hollow plasma generating electrode is a hollow body, and the electrode has at least one through hole communicating with the inside of the hollow at a portion facing the plasma generated by the plasma generating means. It has holes, and at least a part of the inside of the cavity is a region where hollow discharge is generated. As described above, by generating a hollow discharge in at least a part of the inside of the cavity, the density of the plasma can be further increased, so that the excitation and decomposition reaction of the source gas is remarkably promoted, and the speed of the surface treatment is also improved. When the hollow plasma generating electrode is a cathode electrode,
By increasing the surface area of the cathode electrode in contact with the plasma, the self-bias can be controlled to a more positive potential, so that the excitation and decomposition reaction of the source gas is further promoted, and the speed of the surface treatment is remarkably improved.

For an apparatus for performing a surface treatment such as etching, ashing, or ion doping that does not adversely affect the collision of ions with the substrate, the hollow plasma generating electrode is constituted by an anode electrode. The inner wall surface may be a substrate support, and the inside of the anode electrode may be the substrate processing region. In this case, the entire substrate processing region is surrounded by the anode electrode, and the substrate processing region and the plasma generation region are substantially defined.

Since the substrate is directly exposed to the hollow anode discharge, the processing speed of etching, ashing, ion doping, etc. is improved. However, such a surface treatment apparatus in which the inside of the anode electrode is a substrate treatment area defined as a plasma generation area is rather unsuitable for a film forming treatment because ion damage to a substrate is large. .

Further, the hollow plasma generating electrode comprising a hollow body is preferably provided with one or more partitions extending in the height direction inside the hollow in order to increase the surface area. That is, it is preferable that the inside of the cavity of the hollow plasma generating electrode is defined in plural by the partition. In this case, it is necessary to form at least one of the through holes in each of the defined regions.

According to the ninth aspect of the present invention, in order to efficiently generate a hollow discharge inside the hollow plasma generating electrode cavity, the hollow plasma generating electrode has a hollow interior along the forming direction of the through hole. Is H ≦ 5L (e) or H ≦ 2
The range is set so as to satisfy any one of 0X. Where L
(e) is for the source gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom, which are the smallest diameter atoms or molecular species (active species) under the desired plasma generation conditions. This is the mean free path of electrons, and X is the thickness of the sheath layer generated under desired plasma generation conditions. The facing distance H inside the cavity along the forming direction of the through-hole of the hollow plasma generating electrode, which is a hollow body, is:
It is preferable to set a range that also satisfies X / 20 ≦ H, and more preferably a range that also satisfies X / 5 ≦ H.

According to the tenth aspect of the present invention, a magnetic field is formed in the vicinity of the plasma outlet, and / or in the vicinity of the recess, the through hole, and / or inside the cavity. Here, “near” means the plasma outlet, the recess,
Includes the inside of the through hole, the outlet, the concave portion, the opening edge of the through hole, or its vicinity. Further, it is preferable that the magnet is arranged such that the magnetic field lines of the magnetic field are parallel to the axial direction of the plasma outlet, the concave portion, and the through hole, and are parallel to the electrode surface inside the cavity.

The strength of the magnetic field depends on the plasma outlet, the recess,
It is preferably 1 to 2000 mT at the center of the through hole or inside the cavity, and more preferably 5 to 500 mT. In addition, the strength of the magnetic field is preferably 2 to 2000 mT, and more preferably 5 to 1000 mT in the vicinity of the plasma outlet and / or the concave portion, the inner wall surface of the through-hole and the vicinity thereof, or the vicinity of the cavity inner wall portion. .

By arranging the magnetic field in this way, the trajectory of the electrons is adjusted, and the inside and the vicinity of the plasma outlet where the hollow discharge occurs, and the concave portion where the hollow cathode discharge or the hollow anode discharge occurs Alternatively, electrons can stay for a long time inside and near the through hole or inside the cavity, and the generation of active species contributing to the surface treatment is promoted. Therefore, the surface treatment speed is further improved. Since the magnetic field does not change the energy of the electrons at all, the high-quality surface treatment can be maintained without increasing the energy of the electrons to generate ions having an adverse effect.

Further, according to the present invention, there is provided a potential applying means for applying a desired potential to the substrate. The potential applying means can apply the same potential to the substrate, for example, by applying a desired potential to the substrate support table on which the substrate is mounted. Further, the same potential applying means includes a means for monitoring the potential Vs of the process plasma reaching the substrate and the potential of the substrate as necessary. The potential Vs of the process plasma is determined by the potential of the electrode with which most of the plasma contacts. Therefore, the potential Vs of the process plasma can be monitored by monitoring, for example, the high-frequency voltage of the plasma generating electrode and the like and the self-bias.

For example, when a film formation process is performed on a substrate, it is desirable to reduce the voltage difference between the substrate and the process plasma potential Vs in order to suppress ion damage from the plasma. It is more preferable to apply substantially the same potential. The potential applied to the substrate in the case of the film forming process is the potential V of the process plasma.
It is preferably in the range of 1/2 to 1 times s.
In addition, for example, in the case of performing an etching process, the anisotropy can be improved by applying a potential lower than the plasma potential Vs, in particular, a negative voltage.

As described above, by applying a desired potential to the substrate and intentionally controlling the voltage difference between the substrate and the plasma, in the case of film forming processing, the plasma damage can be prevented without reducing the processing speed. In this case, it is possible to control the film quality such as reduction of the film thickness, and in the case of the etching process, it is possible to control the etching shape such as the anisotropy.

It is preferable that a nozzle body protrudes from at least one opening edge of the plasma outlet and / or the concave portion and the through hole. The nozzle body may have its center line aligned with the axial direction of the plasma outlet and / or recess and through hole, or the center line of the nozzle body may be coaxial with the plasma outlet and / or recess and through hole. It may be arranged at an angle to the line direction. Further, the shape of the nozzle body may be a cylindrical body having a constant cross-sectional shape or a cylindrical body whose sectional dimension is gradually reduced or gradually increased. Further, a tubular nozzle body may be spirally arranged.

By protruding the nozzle body from the plasma outlet and / or the recess or through hole, the thickness of the member having the plasma outlet and the hollow plasma generating electrode is unnecessarily increased. The length of the plasma outlet and / or the recess and the through-hole can be freely set without causing the occurrence of hollow discharge at the plasma outlet and / or the recess and the through-hole if the length is increased. Since the area is expanded, the plasma density is increased and the surface treatment speed is also increased.

Further, it is preferable that the nozzle length of the nozzle body is indefinite. That is, the plasma outlet and / or
Alternatively, it is not necessary that all the nozzle bodies have a uniform length in the concave portion, or the plasma outlet and / or the through hole, and can be changed as appropriate. By changing the length of the nozzle body in this manner, the intensity of plasma reaching the substrate can be made uniform over the entire surface of the substrate.

[0064]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings and preferred embodiments. FIG. 1 is a schematic diagram of a surface treatment apparatus 1 according to a first embodiment of the present invention. In the apparatus 1, a casing 2 that blocks the outside air is grounded. Inside the casing 2, two regions, a plasma generation region 3 and a substrate processing region 4, are formed vertically, and a horizontal plate member 6 made of an electrode material is interposed between these regions. .

In the plasma generation region 3, an electrode member 5 is attached to an upper wall 2 a formed of an insulator of the casing 2 in parallel with the plate member 6. The electrode member 5 is connected to a high frequency power supply P,
The plate member 6 disposed in parallel with the electrode member 5 is grounded. By applying electric power to the electrode member 5, a discharge is generated between the electrode member 5 and the plate member 6, and plasma is generated. That is, the electrode member 5 and the plate member 6 constitute a plasma generating electrode, and the electrode member 5 is a cathode electrode, and the plate member 6 is an anode electrode.

In the present invention, as described above, the plate member 6 is separated from the inner wall surface of the casing 2 without being in close contact with the inner wall surface thereof. Installed in Therefore, the installation of the plate member 6 is easy, and the manufacturing cost of the apparatus can be reduced. In this embodiment, the plate member 6 is grounded. However, since the plate member 6 is grounded independently of the casing 2, a desired bias can be applied to the plate member 6. is there. Furthermore, the position of the plate member 6 serving as the anode electrode can be moved up and down to change the distance from the cathode electrode 5. By changing the distance between the anode electrode 6 and the cathode electrode 5, the discharge intensity between the two can be adjusted according to processing conditions such as applied power, for example, and the processing speed and processing quality can be controlled.

The plasma generation region 3 and the substrate processing region 4
A circular through-hole 7 is formed at the center of the plate member 6 interposed between the plate member 6 and the through-hole 7 and constitutes the plasma outlet 7 of the present invention. In this embodiment, the plate member also has a function as an anode electrode, but an anode electrode may be provided separately from the plate member 6.

In the present embodiment, the cross-sectional shape of the plasma outlet 7 is circular. However, other than that, the plasma outlet 7 may have a rectangular shape, or a mounting portion whose diameter increases from the plasma generation region 3 to the substrate processing region 4. It is also possible to adopt a conical shape, a mounting pyramid shape, or a shape in which a substantially half portion on the upstream side is reduced in diameter toward the downstream side, and a half portion on the downstream side is increased in diameter toward the downstream side. . Further, the plasma outlet 7 can be formed in a slit shape.

The opening width W, ie, diameter W, of the plasma outlet 7 is set in a range satisfying either W ≦ 5L (e) or W ≦ 20X. However, L (e) is the atom having the smallest diameter or the molecular species (active species) among the raw gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. By setting such a range, the plasma outlet 7 can be a region where hollow anode discharge is generated. It is preferable that the opening width W is set in a range of X / 20 ≦ W, and further, it is preferable that the opening width W is set in a range of X / 5 ≦ W.

The lower limit of the dimension T in the length direction (thickness direction) of the plasma outlet 7 is approximately X / 50. The upper limit is determined by restrictions on the size of the device, that is, the thickness of the anode electrode 6. The length T of the plasma outlet 7 is 0.1 mm in the case of the above gas pressure and diameter.
〜100 mm is preferred. From the viewpoint of efficiently generating the hollow discharge, the length T of the plasma
The larger the value, the more advantageous it is, and a stronger plasma can be generated. Therefore, a nozzle body can be attached to the opening edge of the plasma outlet 7 to increase the substantial length T of the plasma outlet 7.

In this embodiment, a gas supply port 8 is formed through the upper wall 2a of the casing 2 and the cathode electrode 5, and a gas supply port 8 is formed in the plasma generation region 3 from the gas supply port 8. In the case of film processing, a mixed gas of a source gas such as monosilane and a carrier gas for promoting the generation of plasma and stabilizing the plasma and transporting the source gas to the substrate S is introduced. The gas supply port 8 is not limited to a cylindrical shape, but may be a rectangular tube.

Further, the formation position of the gas supply port 8 is not limited to the above-mentioned position, but can be formed at an arbitrary position. For example, as shown in FIG. 2, it may be formed at a position opening at the bottom of the recess 5a, or may be formed at a position opening at the peripheral wall of the anode electrode 6. Further, a plurality of the gas supply ports 8 may be formed.

It is to be noted that only the carrier gas is introduced from the gas supply port 8 into the plasma generation region 3, and a different introduction port is separately provided for the raw material gas so that the plasma generation region 3, the film formation processing region 4, or the It can also be introduced into the middle of the plasma outlet 7.

In the substrate processing area 4, a substrate support 9 is arranged at a position facing the plasma outlet 7.
In this embodiment, since the substrate support 9 is grounded, the substrate S placed on the support 9 is also grounded. It is possible to apply a DC or AC bias without grounding the substrate support 9, that is, the substrate S, or to apply a bias in a pulsed manner. Alternatively, the substrate S can be electrically insulated from the substrate support 9. Further, the substrate support 9
Has a built-in heater, and adjusts the temperature of the substrate S mounted on the upper surface of the substrate support 9 to a temperature suitable for vapor phase growth.

When a high-frequency power is applied to the cathode electrode 5 by the high-frequency power source P when performing the film forming process by the surface treatment apparatus 1, a discharge occurs between the electrodes 5 and 6, and Plasma is generated.
The source gas and the carrier gas introduced into the plasma generation region 3 are activated by the plasma, and active species contributing to film formation are generated. At this time, the plasma in the plasma generation region 3 flows out of the plasma outlet 7 into the substrate processing region 4 due to the flow of the internal gas accompanying the exhaust from the substrate processing region 4 and further diffusion. The surface of the substrate S in the processing region 4 is subjected to plasma processing by the flow of the plasma, and a thin film is formed on the surface of the substrate 4.

At this time, according to the present invention, by setting the opening width W of the plasma outlet 7 within the above range, a hollow anode discharge is generated in the plasma outlet 7. Since the plasma is newly generated at the plasma outlet 7 by the hollow anode discharge, the density of the plasma guided to the substrate processing region 4 is increased.
Further, when the plasma generated in the plasma generation region 3 passes through the plasma outlet 7, which is a region where hollow anode discharge is generated, the energy of electrons in the plasma is sufficient to generate active species, Since the intensity of the plasma is appropriately reduced to an insufficient level to generate the plasma, the active species contributing to the film formation in the plasma guided to the substrate processing region 4 further increases, the plasma becomes a high density, and the film formation speed is remarkably increased. improves. Furthermore, when passing through the plasma outlet 7 in which the hollow anode discharge is generated, the ion energy in the plasma also decreases, so that the plasma guided to the substrate processing area 4 collides with the substrate and There are few ions that cause damage, and a high-quality film can be formed.

As described above, in this embodiment, the substrate support table 9, that is, the substrate S is grounded.
It is also possible to apply a desired potential without grounding.
In the film forming process, a potential that is 1/2 to 1 times the potential Vs of the process plasma reaching the substrate S is applied to the substrate S, and the difference voltage between the substrate and the process plasma is reduced. In addition, it is possible to form a high-quality thin film by reducing ion damage from plasma.

At this time, the potential V of the process plasma
s is determined by the potential of the electrode with which most of the plasma is in contact. Therefore, the potential Vs of the process plasma can be monitored by monitoring the high-frequency voltage of the cathode electrode and the like and the self-bias.

Further, in this embodiment, a single plasma outlet 7 having a circular cross section is formed. However, when a surface treatment is performed over a large area of the substrate S, the plasma outlet 7 is connected to, for example, FIG. A plurality may be formed in the arrangement shown in FIG. An arrangement based on a regular hexagon shown in FIG. 17A, an arrangement based on a quadrangle shown in FIG. 17B, an arrangement based on a triangle shown in FIG. Further, as shown in FIGS. 18A to 18C, in these arrangements, an arrangement in which a plasma outlet is not formed in a central portion is more preferable. FIG.
(A) and the radial pattern shown in FIG.
It is also preferable to adopt an arrangement excluding the central portion shown in FIG.

Further, if a substantially continuous slit shape which can be written with one stroke, for example, a spiral shape or a meandering shape as shown in FIG. 21, uniform processing can be performed over a large area. It should be noted that in both cases of forming a plurality of holes and slits, the hole diameter and the slit width W are preferably set within the scope of the present invention. However, the plurality of holes need not have a constant diameter, and the slit width does not need to be constant in the length direction. In order to uniformly generate a hollow anode discharge, it is desirable that the hole diameter and the slit width gradually decrease or increase in size from the center portion to the outer edge portion of the anode electrode according to various conditions.

In the above embodiment, the plate member (anode electrode) 6 is grounded.
Can be applied by a DC or AC power supply or a pulse power supply, respectively. At this time, in the present invention, since the plate member 6 is not in close contact with the inner wall surface of the casing 2 and is installed independently of the casing by, for example, a support member from the floor, the bias to the plate member 6 Is easy to apply.

In this embodiment, since the internal gas is exhausted from the substrate processing region 4, the internal gas flows from the plasma generation region 3 to the substrate processing region 4 in the surface processing apparatus. However, the present invention is not limited to this. An exhaust port for the internal gas may be provided in the plasma generation region to reverse the flow of the internal gas. However, in this case, the transport of the plasma from the plasma generation region 3 to the substrate processing region 4 is regarded as diffusion, and the transport of the plasma by the flow of the internal gas cannot be expected. Thus, processing that is faster than in the past is ensured. In addition, gas can be introduced at any position in the casing. In particular, when a gas is introduced from the substrate processing region 4, the effect of diffusion is easily obtained.

Further, when other surface treatments such as ashing, etching, and ion doping are performed by using the above-described apparatus, the surface treatment can be performed at a lower temperature and at a higher speed than before. In the case where, for example, an etching process is performed, the anisotropy can be improved by applying a potential lower than the process plasma potential Vs, in particular, a negative voltage to the substrate S.

Hereinafter, another embodiment of the present invention will be specifically described with reference to the drawings. In the following description, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2 is a schematic view of a surface treatment apparatus 20 according to a second embodiment of the present invention. This embodiment has the same configuration as the first embodiment except that the cathode electrode is different. In the second embodiment, the cathode electrode 10 constitutes the hollow plasma generating electrode of the present invention. That is, a plurality of concave portions 10 a having a circular cross section are formed on the surface of the cathode electrode 10 facing the anode electrode 6. This recess 10
The opening width W of a, that is, the diameter W is W ≦ 5L (e) or W
The range is set so as to satisfy any one of ≦ 20X. However, L (e) is a source gas species and an electrically neutral atom decomposed and generated therefrom under desired plasma generation conditions,
Among the molecular species (active species), it is the mean free path of electrons for the smallest diameter atom or molecular species (active species), and X is the thickness of the sheath layer generated under desired plasma generation conditions.

It is preferable that the opening width W is set in a range of X / 20 ≦ W. Further, the opening width W is set to X / 5 ≦ W.
It is preferable to set in the range of W. When the gas pressure is in the range of 10 to 1400 Pa among the plasma generation conditions, the diameter of the recess 10 a is set in the range of 0.1 to 100 mm, and more preferably 1 to 20 mm.
By setting the diameter of the concave portion 10a in such a range, the concave portion 10a can be a region where hollow cathode discharge is generated.

The plurality of recesses 10a are preferably formed in an arrangement as shown in FIGS. FIG.
The arrangement based on the regular hexagon shown in FIG.
An arrangement based on a square as shown in FIG. 17B, an arrangement based on a triangle as shown in FIG. Furthermore,
As shown in FIGS. 18A to 18C, in these arrangements, it is more preferable that the concave portion 10a is not formed at the center portion, that is, immediately above the plasma outlet 7. In addition, the radial patterns shown in FIGS.
It is also preferable to adopt an arrangement excluding the central portion shown in FIG. 20A and FIG.

The depth D of the recess 10a is approximately X /
50 is the lower limit. The upper limit is determined by restrictions on the size of the device, that is, the thickness of the cathode electrode 10. The depth D of the concave portion 10a is preferably 0.1 mm to 100 mm in the case of the above gas pressure and diameter. In addition, from the viewpoint of efficiently generating the hollow discharge, the concave portion 10a
It is advantageous that the depth D is larger, so that stronger plasma can be generated. Therefore, a substantial depth D of the concave portion 10a can be increased by attaching a nozzle body to the opening edge of the concave portion 5a.

In this embodiment, the recess 10a
Has a circular cross section, but may have other polygonal shapes. The cross-sectional area does not need to be constant, and the cross-sectional area may be changed in the axial direction. Further, the concave portion 10a may have a groove shape such as a rectangular shape, a spiral shape or a meandering shape as shown in FIG. In the case of such a rectangular or spiral groove structure, the opening width W of the concave portion 10a is a groove width (dimension between groove walls), and this groove width is set within the above range. . Note that the groove width may not be constant, and the groove width may be gradually reduced or increased from the center of the cathode electrode 10 to the outer edge. Further, a partial unevenness may be formed on the inner wall surface of the concave portion 10a. It is not necessary that the plurality of recesses 10a have the same size and the same form, and a plurality of recesses 10a having different sizes and forms may be formed.

At this time, since a plurality of recesses 10a are formed in the cathode electrode 10, and the opening width W of the recess 10a is set within the above-described range, the cathode electrode 10 usually has a width depending on the applied high frequency power. From the glow discharge to the discharge including the hollow cathode discharge. Hollow cathode discharge is generated in the concave portion 10a, and new plasma is generated in the concave portion 10a. Therefore, the plasma generated in the plasma generation region 3 is a plasma having a high density, and the number of active species contributing to the film forming process is increased, so that the speed of the surface treatment is increased. In addition, by forming the concave portion 10a in the cathode electrode 10, the surface area of the cathode electrode 10 that substantially comes into contact with plasma increases. Thereby, the self-bias at the time of discharge generation can be taken in a more positive direction, and the excitation and decomposition reaction of the raw material gas in the vicinity of the grounded anode electrode 6 is promoted, and the speed of the surface treatment is improved. be able to.

Furthermore, since hollow cathode discharge occurs in addition to hollow anode discharge at the plasma outlet 7, the electron temperature of the plasma between the electrodes 10 and 6 decreases and the electron density increases. Performance is improved. Further, the hollow cathode discharge reduces the high-frequency voltage at the cathode electrode 10 and increases the self-bias voltage, so that the space potential of the plasma generated between the electrodes 10 and 6 also increases. As a result, a hollow anode discharge easily occurs in the plasma outlet 7, and a synergistic effect that high-density plasma can be generated in the plasma outlet 7 is obtained. Further, for the same reason, the electric field concentration easily occurs in the plasma generation region 3, and it is possible to generate a non-uniform discharge in which a high-density plasma is locally generated.

FIG. 3 is a schematic diagram of a surface treatment apparatus 21 according to a third embodiment of the present invention. The device 21 is different from the first embodiment in that the magnet 11 is arranged on the inner wall surface of the concave portion 10a formed in the cathode electrode 10 and the inner wall surface of the plasma outlet 7, but other configurations are the same as those of the first embodiment. This is the same as the surface treatment apparatus 1 of the first embodiment. The magnet 11
May be arranged so as to apply a magnetic field to the recess 10a and the plasma outlet 7. Accordingly, the magnet 11 may be buried in the inner wall surface as shown in FIG.
It may be buried above “a” or may be arranged outside the cathode electrode 10, or may be a combination of these arrangements. In arranging these magnets 11, it is preferable to attach the magnets 11 so that the magnets 11 are not directly exposed to plasma.

It is preferable that the magnetic field of the magnet 11 is applied such that the direction of the line of magnetic force is parallel to the axis of each of the recess 10a and the plasma outlet 7. The strength of the magnet is 1 to 2000 mT at the center of each axis of the concave portion 110a and the plasma outlet 7, and 2 to 2000 mT at the inner wall surface and its vicinity, and more preferably 5 to 500 mT at the center of the shaft and at the inner wall surface and its vicinity. 5-1000
mT.

By forming a magnetic field in the recess 10a and the plasma outlet 7 in this manner, the trajectory of electrons in the plasma generated there is adjusted by the magnetic field, and the inside of the recess 10a and the plasma outlet 7 is adjusted. Can keep electrons for a long time. By adjusting the electron trajectory, the action time of the electrons on the source gas can be increased without increasing the energy (electron temperature) of the electrons, so that the generation of active species is promoted and the film forming speed is improved.

Further, by forming the magnetic field by arranging the magnet 11, the allowable range of the dimension of the opening width W and the depth D of the concave portion 10a or the opening width W of the plasma outlet 7 is such that the magnet 11 is arranged. Spread about 30% compared to the case without.

In this embodiment, the magnets 11 are arranged in all the recesses 10a and the plasma outlets 7. However, the magnets 11 are not arranged in all of them, and the magnets 11 are arranged only in a selected one. They can also be placed. Furthermore, a magnetic field can be formed by means such as an electromagnet. Also,
The arrangement of the magnetic field including the polarity of the magnet and the strength of the magnetic field are arbitrarily set so as to increase the plasma density.

FIG. 4 is a schematic diagram of a surface treatment apparatus 22 according to a fourth embodiment of the present invention. This surface treatment device 22 also
Plasma generation area 3 and substrate processing area 4 in casing 2
A plate member 6 'is interposed between the two regions. The plate member 6 'is an anode electrode of a plasma generating electrode, and a circular plasma outlet 7' is formed at the center of the anode electrode 6 '.

The cathode electrode 10 has a plurality of recesses 10a having a circular cross section on the surface facing the anode electrode 6 '.
Are formed, and the opening width W of the concave portion 10a is W ≦
The range is set so as to satisfy either 5L (e) or W ≦ 20X. More preferably, the opening width W is X / 5
≦ W is set. By setting the diameter of the concave portion 10a in such a range, a hollow cathode discharge occurs in the concave portion 10a.

The configuration of the present embodiment is the same as that of the second embodiment described above, but the opening width W of the plasma outlet 7 'formed in the anode electrode 6' is large, or the length ( This is different from the surface treatment apparatus 1 of the first embodiment in that no hollow discharge is generated at the plasma outlet 7 'because the thickness (T) is small.

In this embodiment, since the hollow discharge does not occur at the plasma outlet 7 ', the speed and quality of the surface treatment are slightly inferior to those of the first embodiment, but the hollow cathode discharge is formed in the concave portion 10a of the cathode electrode 10. Therefore, the processing speed and the processing quality are improved as compared with the conventional surface treatment apparatus.

FIG. 5 is a schematic view of a surface treatment apparatus 23 according to a fifth embodiment of the present invention. The device 23 is different from the second embodiment in that the cathode electrode 12 which is the hollow plasma generating electrode of the present invention is a hollow cylindrical hollow body,
Other configurations are the same as those of the surface treatment apparatus 1 of the second embodiment.

The cathode electrode 12, which is a hollow body, has a plurality of through-holes having a circular cross section communicating with the inside of the cavity in a portion facing the plate member (anode electrode) 6, ie, a lower wall portion 12a of the cathode electrode 12. 12b is formed. This through-hole 12b is preferably formed in an arrangement as shown in FIGS. In addition, this through hole 12
b denotes a plasma outlet 7 formed in the anode electrode 6
It is more desirable to form it in a position avoiding the position immediately above the above, that is, in the arrangement shown in FIG.

The opening width W, that is, the diameter W, is set to a range satisfying either W ≦ 5L (e) or W ≦ 20X so that the through-hole 12b can be used as a hollow cathode discharge generating region. However, L (e) is the atom having the smallest diameter or the molecular species (active species) among the raw gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. The opening width W is preferably set in a range of X / 20 ≦ W, and more preferably in a range of X / 5 ≦ W.

Further, the plurality of through holes 12b have an opening width W.
Are not necessarily the same, and in order to uniformly generate a hollow cathode discharge in the plurality of through holes 12b,
A different opening width W can be appropriately set. In particular,
Depending on the frequency of the applied power or under other conditions, the through-hole 12b near the center decreases the opening width W and gradually increases the opening width W in the outer edge direction, or increases the opening width W near the center. It is preferable to gradually decrease the opening width W in the outer edge direction.

Among the above plasma generation conditions, when the gas pressure is 10
When the pressure is within the range of 1400 Pa,
The diameter of b is set in the range of 0.1 to 100 mm, more preferably 1 to 20 mm. By setting the diameter of the through hole 12b in such a range, the through hole 12b
A hollow cathode discharge occurs at b.

The lower limit of the length T of the through hole 12b, that is, the thickness T of the lower wall portion 12a in this embodiment is approximately X / 50. The upper limit is determined by restrictions on the size of the device. The length T of the through hole 12b is preferably 0.3 to 70 mm in the case of the gas pressure and the diameter described above.

In this embodiment, the through holes 12
b is a circular cross-section, but also elliptical, rectangular, polygonal,
Any shape such as an irregular shape can be used. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. Further, the through hole 12b may have a slit structure having a rectangular cross section, or a slit structure having a one-dimensional spread such as a spiral shape or a meandering shape as shown in FIG. In the case of such a slit structure, the opening width W of the through hole 12b is a slit width, and this slit width is set within the above-described range. In addition,
This slit width may not be constant, and may be gradually increased or decreased from the center toward the outer edge. In addition, partial unevenness may be formed on the inner wall surface of the through hole 12b.
It is not necessary that the plurality of through holes 12b have the same size and the same form, and a plurality of through holes 12b having different sizes and forms may be formed.

Further, in the present embodiment, the inside of the cavity of the cathode electrode 12 along the direction in which the through holes 12b are formed is formed so that the inside of the cavity of the cathode electrode 12 can be used as a region for generating a hollow cathode discharge. The distance, that is, the height H in the drawing, is set in a range that satisfies either H ≦ 5L (e) or H ≦ 20X. However, L (e) is the atom having the smallest diameter or the molecular species (active species) among the raw gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. The height H inside the cavity is preferably set in a range of X / 20 ≦ H, and more preferably in a range of X / 5 ≦ H. When the gas pressure is in the range of 10 to 1400 Pa as described above and the size of the through hole 11b is in the above range, the height H inside the cavity is 0.1 to 100 mm. , And more preferably, the height H inside the cavity is set to 1 to 20 mm.

In the illustrated example, the height H inside the cavity is constant, but the height H may not be constant.
In at least a part of the inside of the cavity, the height H may be set within the range described above. In order to generate a hollow cathode discharge uniformly over substantially the entire region inside the cavity, the height H inside the cavity near the center is reduced depending on the frequency of the applied power or other conditions, and the height H is reduced toward the outer edge. It is preferable to gradually increase the height H, or increase the height H near the center and gradually decrease the height H in the outer edge direction.

Further, in the illustrated example, the cathode electrode 12 is a hollow body having a substantially uniform thickness in the wall and being entirely hollow. However, the peripheral wall is thickened, and only the central portion is hollow. Alternatively, a local hollow portion can be formed. Further, a concave portion can be formed in the hollow portion.

A cylindrical gas supply port 12d is formed at the center of the upper wall portion 12c of the cathode electrode 12, and a raw material gas such as monosilane and plasma are supplied from the gas supply port 12d into the inside of the cavity of the cathode electrode 11. A mixed gas with a carrier gas for promoting generation, stabilizing plasma, and transporting the source gas to the substrate S is introduced.
The gas supply port 12d is not limited to a cylindrical shape, but may be a rectangular cylindrical shape. Further, the formation position of the gas supply port 12d is not limited to the center of the upper wall portion 12c, but may be formed at an arbitrary position in an arbitrary number.

The mixed gas introduced from the gas supply port 12d into the inside of the cathode electrode 12 is supplied to the through hole 1d.
2b is introduced into the plasma generation region 3 in a shower shape. As described above, once the mixed gas is stored inside the cathode electrode 12, the mixed gas is introduced into the plasma generation region 3 in the form of a shower from the through hole 12b so that the mixed gas has a uniform concentration and pressure. It can be introduced into the plasma generation region 3.

It is to be noted that only the carrier gas is introduced into the cavity of the cathode electrode 12 and the raw material gas is separately provided with a different inlet so that the inside of the plasma generating region 3, the inside of the film forming region 4, or It can also be introduced into the middle of the plasma outlet 7.

When high-frequency power is applied to the cathode electrode 12 by the high-frequency power source P, discharge occurs between the electrodes 12 and 6, and plasma is generated in the plasma generation region 3. The transition from normal glow discharge to discharge including hollow cathode discharge is made according to the applied high frequency power. At this time, in the cathode electrode 12, a hollow cathode discharge is generated in the through-hole 12b, a new plasma is generated in the through-hole 12b, and a hollow cathode discharge is also generated inside the cavity of the cathode electrode 12. New plasma is being generated. Therefore, the plasma generated in the plasma generation region 3 is a plasma having a high density, and the number of active species contributing to the film forming process is increased, so that the speed of the surface treatment is increased.

Further, since the cathode electrode 12 is a hollow body, and a through-hole 12b is formed and plasma is generated between the through-hole 12b and the inside of the cavity, the cathode electrode 12 which substantially contacts the plasma is formed. The surface area is the second
It increases further than in the case of the embodiment. Thereby, the self-bias at the time of discharge generation can be brought to the more positive side, and the excitation and decomposition reaction of the raw material gas in the vicinity of the grounded anode electrode 6 is promoted, and the speed of the surface treatment is further improved. Can be done.

Further, a magnet can be arranged at an appropriate place so as to form a magnetic field in the cavity of the cathode electrode 12 which is a hollow body or in the through hole 12b. In that case,
The magnetic field of the magnet is desirably applied so that the direction of the magnetic field lines is parallel to the axial direction of the through hole 12b, and is parallel to the electrode surface inside the cavity. The strength of the magnet is 1 to 1 at the center of the through hole and the inside of the cavity.
2000 mT, 2 to 2000 mT on the inner wall surface and the vicinity of the through hole and the cavity, and more preferably 5 to 5 m at the center
500 mT, and 5 to 1000 mT on the inner wall surface and its vicinity.

By forming a magnetic field inside the through-hole 12b and the cavity as described above, the trajectory of the electrons in the plasma generated there is adjusted by the magnetic field, and
b and the electrons can stay in the cavity for a long time.
By adjusting the electron trajectory, the action time of the electrons on the source gas can be increased without increasing the energy (electron temperature) of the electrons, so that the generation of active species is promoted and the film forming speed is improved.

It is not necessary to form a magnetic field in all the through holes 12b, and a magnetic field can be formed only in one of the selected through holes 12b. It is also possible to form a magnetic field by means such as an electromagnet.

Further, the through hole 1 in the cathode electrode 12
In order to increase the plasma density generated by the hollow cathode discharge inside 2b or its cavity,
From the viewpoint of efficiently generating a hollow cathode discharge in b, it is advantageous that the length T of the through-hole 12b is large, and a stronger plasma can be generated. However, the lower wall 12 of the cathode electrode 12
The thickness of a is desirably the minimum thickness that can withstand the gas pressure and applied power introduced into the cavity from the viewpoint of material cost.

For this reason, in order to increase the length T of the through hole 12b, it is desirable to attach a nozzle body to the periphery of the through hole 12b. The nozzle body may be protruded from the through hole 12b toward the plasma generation region 3 or may be protruded into the cavity. Further, it may be provided on both sides. Further, the nozzle body may be constituted by a magnet. However, it is preferable that the magnet is not directly exposed to the plasma.

The nozzle body has its center line aligned with the through hole 12.
The center line of the nozzle body may be arranged at an angle with respect to the axis of the through hole 12b, that is, the nozzle body may be arranged obliquely. Further, the nozzle body may be a cylindrical body having a constant cross-sectional area, a cylindrical body having a shape for gradually increasing or decreasing the cross-sectional area, or a tube-shaped nozzle body may be spirally arranged. Regarding the deformation of the nozzle body, the plasma outlet 7 and the recess 1 described above are used.
The present invention can also be applied to a nozzle body attached to Oa.

Further, the cathode electrode 1 with which the plasma contacts
In order to increase the surface area of the cathode electrode 2, the inside of the cavity of the cathode electrode 12 may be partitioned by a partition extending in the height direction. Since the surface area can be freely adjusted in this way, the self-bias of the cathode electrode 12 can be freely controlled. The partition does not have to be in close contact with the upper and lower walls of the cathode electrode 12, and a space may be formed and each partitioned space may be in communication.

It is desirable to provide a gas supply port in each of the partitioned spaces. Alternatively, a gas supply port can be formed at a position that opens in the peripheral wall of the anode electrode, or a plurality of gas supply ports can be formed by combining the plurality of gas supply ports. Only a carrier gas is introduced from the gas supply port of the cathode electrode 12, and a raw material gas is provided in the plasma generation region 3 by providing a gas supply port of the anode electrode or a different introduction port separately. It can also be introduced into the region 4 or into the plasma outlet 7.

In the above-described fifth embodiment in which the cathode electrode 12 is a hollow body, a hollow cathode discharge occurs in almost the entire area inside the hollow of the cathode electrode 12, as shown in FIG. However, depending on the height of the inside of the cavity of the cathode electrode 12, the shape, the number, and the arrangement of the through-holes 12d, the arrangement of the magnets, etc., the hollow discharge may not be generated over the entire area of the inside of the cavity. A hollow cathode discharge may occur only in a part of the cavity, or a non-uniform hollow cathode discharge may occur in the cavity. As a general tendency, in the hollow portion near the through-hole causing the hollow discharge, a hollow discharge brighter than the others is generated inside the cavity. Hollow discharge does not occur in any of the through holes 12b, and even if hollow discharge occurs only in at least a part of the inside of the cavity, there is an effect that both processing speed and quality are improved.

FIG. 6 shows a surface treatment apparatus 2 according to the sixth embodiment.
4 is a schematic view of FIG. The device 24 includes a cathode electrode 12 ′
So that hollow cathode discharge does not occur inside the cavity of
The fifth embodiment is different from the fifth embodiment in that the inner wall surface inside the cavity is made of an insulator, but other structures are the same as those of the fifth embodiment.
This is the same as the surface treatment device 23 of the embodiment.

However, a part of the electrode may be exposed on the inner surface of the lower wall portion 12a of the cathode electrode 12 '. In this case, the plasma generated in the plasma generation region 3 passes through the through-hole 12b into the cavity. And can crawl on the exposed electrode surface. Thereby, the surface area of cathode electrode 12 'with which the plasma can substantially contact can be increased, and the self-bias can be increased.

In order to prevent the hollow cathode discharge from being generated inside the cavity of the cathode electrode 12 ', in addition to the above-mentioned configuration in which the inner wall surface is made of an insulator, the height H inside the same cavity is reduced. There is a method of increasing the height, but since the height H changes depending on the RF power and the gas pressure, a method of forming the inner wall surface with an insulator is more reliable.

As described above, the place where plasma is generated can be controlled, the surface area of the cathode electrode 12 'in contact with plasma can be adjusted, and the self-bias can be controlled.
It is possible to generate a plasma having a strength corresponding to the application.

As a modified example of the above-described cathode electrode 12 which is a hollow body, a plurality of through holes 15b communicating with the inside of the cavity are provided, for example, as in a cathode electrode 15 which is a hollow body shown in FIG. The lower wall 15a and the upper wall 15
c can be vertically divided into a plurality of stages by one or more partition walls 15e having one or more through holes 15d. At this time, a plurality of through-holes 13b formed in the lower wall portion 15a and a plurality of through-holes formed in the partition wall 15e like a cathode electrode 15 'which is a hollow body shown in FIG. It is preferable to form the respective through holes 15b and 15d so that the through holes 15b and 15d do not overlap each other in the vertical direction.

Further, the number of the through holes 15b and 15d may be different between the lower wall 15a and the partition wall 15e.
In addition, the opening size of each through hole 15b, 15d also
a and the partition wall 15e may be different from each other. Further, it is not necessary that all of the plurality of through holes 15b of the lower wall portion 15a and the plurality of through holes 15d of the partition wall 15e have uniform opening dimensions. Alternatively, the opening size may be varied so as to gradually decrease or increase from the center portion toward the outer edge.

As still another modification of the above-described hollow cathode electrode 12, a plurality of hollow electrode members 16 such as a hollow cathode electrode 16 shown in FIG.
a can be connected vertically in a plurality of stages by the connection port 16b. An arbitrary point in the illustrated space can be a generation region of the hollow discharge plasma.

In each of the above-described embodiments, the plasma generation region 3 is provided above the surface treatment apparatus, and the substrate processing region 4 is provided therebelow. In contrast to these embodiments, the plasma generation region 3 is provided below. It is also possible to provide a substrate processing region above, and to make the plasma flow out from below to above. Furthermore, it is also possible to arrange the plasma generation region and the substrate processing region horizontally on the left and right sides in the casing of the surface treatment device, and to make a device of a type in which the plasma flows out in the lateral direction. In any case, the substrate can be arranged to face the plasma outlet and orthogonal to the plasma outflow direction, or the substrate can be arranged in parallel to the plasma outflow direction. Further, the plasma generating means is not limited to a pair of plasma generating electrodes. For example, a discharge having three or more electrodes, a microwave discharge, a capacitively coupled discharge, an inductively coupled discharge, a PIG discharge, an electron beam excited discharge And a plasma generating means.

As shown in FIGS. 8A and 8B,
Cathode electrodes 10 and 12 where hollow cathode discharge occurs
Another electrode 13 may be arranged in the vicinity of the anode electrode side and / or the opposite side. The other electrode 13 has a large number of small holes 13a having an opening width smaller than the opening width W of the concave portion 10a formed in the cathode electrode 10 or the through hole 12b formed in the hollow cathode electrode 12. Alternatively, the other electrode 13 may be in a mesh shape. Note that, even in the case of a cathode electrode having a through hole in which hollow cathode discharge occurs, similarly, another electrode in which a large number of small holes smaller than the opening width W of the through hole can be provided. .

The other electrode 13 is biased to an arbitrary voltage including a floating state, and particularly preferably, to a voltage value between the voltage of the grounded anode electrode 6 and the maximum value of the space potential of the plasma. Set or
It is set to a voltage value between the voltage of the cathode electrode 10 where the hollow cathode discharge is generated and the maximum value of the space potential of the plasma.

Further, as shown in FIG. 8, the small holes 13a formed in the other electrode 13 are formed in the cathode electrodes 10, 1.
If the holes are formed at positions corresponding to the two concave portions 10a or the through holes 12b, electrons are further confined in the hollow cathode discharge region, and an ultra-high-density hollow cathode discharge, which is a larger current discharge, becomes possible.

Alternatively, as shown in FIGS. 9A and 9B, a concave portion 10a ″ formed in the cathode electrode 10 ″.
Also, in the through hole 12b "formed in the cathode electrode 12", the area of the opening is smaller than that of the recess 10a "or the through hole 1b.
By forming the cross-sectional area to be sufficiently smaller than the cross-sectional area of the other portion of 2b ", electrons can be efficiently confined in the hollow portion 10a" or the through-hole 12b "which is a hollow cathode discharge region or in the hollow portion. In the figure, the concave portion 10a "and the through hole 12b" have a cylindrical shape in the upper half and a hemispherical shape in the lower half, but may have a conical shape, a pyramid shape, or a spindle shape.

FIG. 10 is a schematic view of a surface treatment apparatus 25 according to a seventh embodiment of the present invention. The device 25 is the first device described above in that the plate member 14 functioning as an anode electrode disposed in parallel to the cathode electrode 5 is a hollow body.
Although different from the embodiment, other configurations are substantially the same as the surface treatment apparatus 1 of the first embodiment.

At the center of the anode electrode 14, a single plasma outlet 7 penetrating the upper wall portion 14a and the lower wall portion 14b in a straight line is formed. Furthermore, in the present embodiment, the facing distance along the forming direction of the plasma outlet 7 inside the cavity, that is, the vertical distance in the figure, so that the inside of the cavity of the anode electrode 14 can be used as a hollow anode discharge generation area. The height H between the wall portions 14a, 14b is H ≦ 5L.
(e) or a range satisfying either H ≦ 20X. However, L (e) is the atom having the smallest diameter or the molecular species (active species) among the raw gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. The height H inside the cavity is X /
It is preferable to set the range of 20 ≦ H.
It is preferable to set the range of / 5 ≦ H.

In this embodiment, in addition to the hollow anode discharge at the plasma outlet 7, a hollow anode discharge is generated inside the cavity of the anode electrode 14.
New plasma is also generated inside the cavity of the anode electrode 14. Therefore, the density of the process plasma reaching the substrate S further increases, and the number of active species contributing to the film forming process increases, so that the surface processing speed is improved and the processing quality is further improved. Needless to say, even when hollow discharge is generated only in one of them, the processing speed and quality are improved as compared with the related art.

In the illustrated example, the height H inside the cavity of the anode electrode 14 is constant, but the height H may not be constant. In order to generate a hollow anode discharge uniformly over substantially the entire area inside the cavity, the height H inside the cavity near the center is reduced according to the frequency of the applied power or other conditions, and the height H is increased in the outer edge direction. It is preferable to gradually increase the height H, or increase the height H near the center and gradually decrease the height H in the outer edge direction.

Alternatively, it is not necessary for the anode electrode 14 to generate a hollow anode discharge in the entire interior of the cavity. If at least a part of the anode electrode 14 can generate a hollow anode discharge, the quality of the surface treatment and the processing speed can be improved. .

FIG. 11 shows a modified example of the anode electrode 14 which is the above-mentioned hollow body. Although the above-described anode electrode 14 is formed through the single plasma outlet 7 at the center, as shown in an anode electrode 14 ′ shown in FIG. 11, a cavity is formed in each of the upper wall portion 14 a and the lower wall portion 14 b. It is also possible to form a plurality of through holes 14c as plasma outlets communicating with the inside. In this case, it is preferable that the through-holes 14c of the upper wall portion 14a and the through-holes 14c of the lower wall portion 14b are formed so as to be shifted from each other so as not to be vertically aligned. Further, it is preferable to form the through holes 14c in the arrangement shown in FIGS.

The plurality of through holes 14c have an opening width W.
May not be all the same, and in order to uniformly generate a hollow anode discharge in the plurality of through holes 14c,
A different opening width W can be appropriately set. In particular,
Depending on the frequency of the applied power or depending on other conditions, the through hole 14c near the center decreases the opening width W and gradually increases the opening width W in the outer edge direction, or increases the opening width W near the center. It is preferable to gradually decrease the opening width W in the outer edge direction.

The lower limit of the length T of the through hole 14c, that is, the thickness T of the lower wall portion 14a in this embodiment is approximately X / 50. The upper limit is determined by restrictions on the size of the device. The length T of the through hole 14c is preferably 0.1 to 70 mm in the case of the gas pressure and the diameter described above.

In this embodiment, the through holes 14 are used.
c is a circular cross section, but also elliptical, rectangular, polygonal,
Any shape such as an irregular shape can be used. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. Further, the through hole 14c may have a slit structure having a rectangular cross section, or a slit structure having a one-dimensional spread such as a spiral shape or a meandering shape as shown in FIG. In the case of such a slit structure, the opening width W of the through hole 14c is a slit width, and this slit width is set within the above-described range. Also,
Partial unevenness may be formed on the inner wall surface of the through hole 14c. The plurality of through-holes 14c do not need to have the same dimensions and the same form, and a plurality of through-holes 14c having different dimensions and forms may be formed.

The anode electrode 14 'may be provided with a gas supply port 8' which opens into the inner wall surface of the through hole 14c or the inside of the cavity. For example, in the case of a film forming process, only a carrier gas is introduced into the plasma generation region 3,
By introducing a raw material gas such as monosilane from the gas supply port 8 'of the anode electrode 14', decomposition of the raw material gas in an unnecessary space is prevented, and the raw material gas is efficiently contributed to a film forming process. Can be. The plurality of through holes 1
The gas supply ports 8 'can be provided in all of the holes 4c, or the gas supply ports 8' can be provided only in some of the through holes 14c. Further, a plurality of gas supply ports 8 'can be opened on the inner wall surface inside the cavity.

Further, FIGS. 12 and 1 show a modification in which the plasma density generated by the hollow anode discharge in the cavity inside the anode electrode 14 'and the through hole 14c is increased.
3 is shown. First, from the viewpoint of efficiently generating a hollow anode discharge in the through-hole 14c, it is advantageous that the length T of the through-hole 14c is larger, so that stronger plasma can be generated. However, the thickness of the upper and lower wall portions 14a and 14b of the anode electrode is desirably the minimum thickness that can withstand the gas pressure and applied power introduced into the cavity from the viewpoint of material cost.

Therefore, in order to increase the length T of the through hole 14c, it is desirable to attach the nozzle body 17 to the periphery of the through hole 14c of the lower wall portion 14b. The nozzle body 17 may project from the through-hole 14c toward the substrate processing region 4, or may project from the hollow body 14a. Further, it may be provided on both sides. Also,
The nozzle body 17 may be constituted by the magnet 11 as shown in FIG. At this time, it is preferable that the magnet 11 is arranged so as not to be directly exposed to the plasma.

The center line of each of the nozzle bodies 17 shown in FIG. 12 is aligned with the line of the through hole 14c, but the center line of the nozzle body 17 is aligned with the through hole 14c.
Are arranged at an angle with respect to the axis of
7 can be arranged diagonally. Further, the nozzle body 17 shown in FIG. 12 is a cylindrical body having a constant cross-sectional area, but is not limited to such a shape, and may be a cylindrical body having a shape that gradually increases or decreases its cross-sectional area. Further, the tube-shaped nozzle body may be spirally arranged.

Further, the anode electrode 1 with which the plasma contacts
In order to increase the surface area of the anode electrode 4 '
A partition extending in the vertical direction or a partition extending in the horizontal direction may be provided inside the cavity 4 'to divide the interior into a plurality of chambers. The through holes 14c formed in each of the divided inner chambers may be the same or different. Further, the partition extending in the vertical direction,
A gap is formed between the upper and lower walls 14a, 14b,
Each room may communicate.

In addition, the anode electrode 14 'is
As shown in FIG.
The magnet 11 can be buried in the inner peripheral surface of each through hole 14c, the upper and lower wall portions 14a, 14b, or the peripheral wall portion, or can be disposed near the inner peripheral surface of each through hole 14c so as to apply a magnetic field to c or the inside of the cavity. The direction of the line of magnetic force of the magnet 11 is
The magnetic field is applied so as to be parallel to the axis direction of the vertical axis c, or the directions of the lines of magnetic force are adjusted to the upper and lower wall portions 14a, 14b.
It is preferable that the magnetic field is applied so that the magnetic field is applied so as to be parallel.

By forming a magnetic field inside the through hole 14c and the cavity as described above, the trajectory of electrons in the plasma generated there is adjusted by the magnetic field, and
Electrons can stay for a long time in c and the inside of the cavity. By adjusting the electron trajectory, the action time of the electrons on the source gas can be increased without increasing the energy (electron temperature) of the electrons, so that the generation of active species is promoted and the film forming speed is improved. The structure shown in FIG. 12 and FIG.
The cathode electrodes 10, 10 ', 10 ", 12, and 12 shown in FIG.
Similar effects can be obtained by applying the present invention to 12 ', 12 ", 15, 15', and 16.

In the surface treatment apparatus 25 of the seventh embodiment in which the plate member 14 serving as the anode electrode is a hollow body, the cathode electrode 5 is replaced with the hollow cathode as shown in the second to sixth embodiments. Of course, it is also possible to change to the cathode electrodes 10 and 12 having a discharge region.
In this case, each of the embodiments has the same effects as those of the above-described embodiments, and the hollow anode discharge and the hollow cathode discharge increase the density of the process plasma, thereby significantly improving various processing speeds.

FIG. 14 is a schematic view of a surface treatment apparatus 26 according to an eighth embodiment of the present invention. The surface treatment apparatus 40 includes a plate member 18 formed of a hollow body and also serving as an anode electrode.
Constitute a substrate processing region 4 '. An anode electrode 18 formed of a hollow body has a through hole 1 at the center of the upper wall portion 18a.
8b is formed, and the through hole 18b forms a plasma outlet. A central portion of the inner surface of the lower wall portion 18c of the anode electrode 18 forms a substrate support, and a plurality of exhaust ports 18d are provided at a peripheral portion of the lower wall portion 18c.
Are formed. Further, a heating means for the substrate can be provided in the center of the lower wall portion 18c. The position for supporting the substrate in the anode electrode 18 and the position for forming the exhaust port 18d are not limited to those described above, and any position can be selected.

In this embodiment, the anode 1
The width W of the through-hole 18b is set to W ≦ 5L (e) so that the through-hole 18b of FIG.
Alternatively, it is set in a range that satisfies either W ≦ 20X. Further, the opening width W is preferably set in a range of X / 20 ≦ W, and more preferably set in a range of X / 5 ≦ W. In the present embodiment, the height H inside the cavity is set to any one of H ≦ 5L (e) or H ≦ 20X so that the inside of the cavity of the anode electrode 18 can also be used as a region for generating hollow anode discharge. Is set in a range that satisfies The height H inside the cavity is preferably set in the range of X / 20 ≦ H, and more preferably in the range of X / 5 ≦ H.

Here, L (e) is an atom or molecule having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom under the desired plasma generation conditions. It is the mean free path of electrons with respect to the species (active species), and X is the thickness of the sheath layer generated under desired plasma generation conditions.

In the substrate processing apparatus 26, the substrate processing region 4 'is formed inside the cavity of the anode electrode 18, and a hollow anode discharge is generated inside the cavity of the anode electrode 18, so that the substrate S is processed. The density of the contributing plasma is extremely increased, and the processing speed is significantly improved. However,
This substrate processing apparatus 26 is rather unsuitable for a film forming process because the ion damage to the substrate S by the plasma is large, and the apparatus 26 is more suitable for etching, ashing, or ion doping.

FIGS. 15 and 16 show a modification of the plate member (anode electrode) comprising a hollow body constituting the substrate processing region 4 '. An anode electrode 18 'shown in FIG. 15 has a plurality of through holes 18 forming a plasma outlet in an upper wall portion 18a.
This is different from the above-mentioned anode electrode 18 in that b is formed. The through holes 18b are preferably formed in an arrangement as shown in FIGS.

The plurality of through holes 18b have a circular cross section in this embodiment, but may have any other shape such as an elliptical shape, a rectangular shape, a polygonal shape, and an irregular shape. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. Further, the through hole 18b may have a slit structure having a rectangular cross section, or a slit structure having a one-dimensional spread such as a spiral shape or a meandering shape as shown in FIG. In the case of such a slit structure, the opening width W of the through hole 18b is a slit width, and this slit width is set within the above-described range. Further, a partial unevenness may be formed on the inner wall surface of the through hole 18b. The plurality of through holes 18b do not need to have the same size and the same form as each other, and a plurality of through holes 18d having different sizes and forms may be formed.

The anode 18 ″ shown in FIG.
Are the plasma outlet, the through hole 18b and the exhaust port 1
8d, the magnet 11 is buried in the inner peripheral surface of each through hole 18b and the exhaust port 18d, the upper and lower wall portions 18a, 18c, or the peripheral wall portion inside the cavity so as to apply a magnetic field to the inside of the cavity, or in the vicinity thereof. Can be arranged. The magnet 11 is applied with a magnetic field such that the direction of the line of magnetic force is parallel to the axial direction of the through hole 18b or the exhaust port 18d, or the direction of the line of magnetic force is parallel to the upper and lower wall portions 18a and 18d. It is preferable that the magnetic field is applied to the magnetic field. FIG. 16 shows various specific examples of the arrangement of the magnets in one figure, and the arrangement of the magnets may be only a part.

As described above, the through hole 1 serving as the plasma outlet is
By forming a magnetic field in the inside of the cavity 8b or the cavity, the trajectory of the electrons in the plasma generated therein can be adjusted by the magnetic field, and the electrons can stay in the through hole 18b or the inside of the cavity for a long time. By adjusting the electron trajectory, the action time of the electrons on the source gas can be increased without increasing the energy (electron temperature) of the electrons, so that the generation of active species is promoted and the film forming speed is improved. The electrode 18 can also have the above-described configuration such as a partition plate and a nozzle body shown in FIG.

In the various embodiments and modifications of the present invention described above, high-frequency power is supplied to the plasma generating electrode by the high-frequency power supply P. However, a DC voltage may be applied by a DC power supply. Alternatively, the bias may be applied by a DC or AC power supply or a pulse power supply, respectively.
It is also possible to arrange a mesh electrode between the substrate S arranged in the surface treatment region 4 and the plasma outlet 7 to form a triode type, and to apply various biases. Furthermore, direct current is applied only to the nozzle or through-hole.
A bias may be applied by an AC or pulse power supply.
In this case, only the nozzle body or the through-hole portion is electrically insulated from other portions of the electrode.

[Brief description of the drawings]

FIG. 1 is a schematic view of a surface treatment apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a surface treatment apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic view of a surface treatment apparatus according to a third embodiment of the present invention.

FIG. 4 is a schematic view of a surface treatment apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a schematic view of a surface treatment apparatus according to a fifth embodiment of the present invention.

FIG. 6 is a schematic view of a surface treatment apparatus according to a sixth embodiment of the present invention.

FIG. 7 is a schematic view showing another embodiment of a hollow cathode electrode.

FIG. 8 is a schematic view of a cathode electrode part in a surface treatment apparatus according to another embodiment of the present invention.

FIG. 9 is a schematic view of a cathode electrode part in a surface treatment apparatus according to still another embodiment of the present invention.

FIG. 10 is a schematic diagram of a surface treatment apparatus according to a seventh embodiment of the present invention.

FIG. 11 is a schematic view showing a modified example of the anode electrode in the seventh embodiment.

FIG. 12 is a schematic view showing another modification of the anode electrode in the seventh embodiment.

FIG. 13 is a schematic diagram showing still another modified example of the anode electrode in the seventh embodiment.

FIG. 14 is a schematic view of a surface treatment apparatus according to an eighth embodiment of the present invention.

FIG. 15 is a schematic view showing a modified example of the anode electrode in the eighth embodiment.

FIG. 16 is a schematic view showing another modification of the anode electrode in the eighth embodiment.

FIG. 17 is a diagram showing an example of arrangement of a large number of through holes or concave portions.

FIG. 18 is a diagram showing another example of the arrangement of a large number of through holes or concave portions.

FIG. 19 is a diagram showing still another arrangement example of a large number of through holes or concave portions.

FIG. 20 is a view showing still another arrangement example of a large number of through holes or concave portions.

FIG. 21 is an explanatory diagram of a spiral through hole or a concave portion.

[Explanation of symbols]

1, 20 to 26 Surface treatment device 2 Casing 2a Upper wall 3 Plasma generation area 4 Substrate processing area 5 Cathode electrode 6 Plate member (anode electrode) 7 Plasma outlet 8 Gas supply port 9 Substrate support 10 Cathode electrode 10a Recess 11 Magnet Reference Signs List 12 cathode electrode 12a lower wall 12b through hole 12c upper wall 12d gas supply port 13 other electrode 13a small hole 14 anode electrode 14a upper wall 14b lower wall 14c through hole 15 cathode electrode 15a lower wall 15b through hole 15c Upper wall portion 15d Through hole 15e Partition wall 16 Cathode electrode 16a Hollow electrode member 16b Connection port 17 Nozzle body 18 Anode electrode 18a Upper wall portion 18b Through hole 18c Lower wall portion 18d Exhaust port S Substrate P High frequency power supply

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Koichi Ishida 1200 Manda, Hiratsuka-shi, Kanagawa Prefecture Inside the Komatsu Seisakusho Research Headquarters (72) Inventor Hiroyuki Mizukami 1200 Manda, Hiratsuka-shi, Kanagawa Pref. (72) Inventor Yasuma Toyoshima 1200 Manda, Hiratsuka-shi, Kanagawa Prefecture Inside Komatsu Seisakusho R & D Headquarters (72) Inventor Shinichi Fujimoto 1200 Manda, Hiratsuka-shi, Kanagawa Prefecture Komatsu Seisakusho Research Headquarters F-term (reference) 4K030 EA06 FA03 KA17 KA18 KA34 5F004 AA16 BA06 BB13 CA03 5F045 AA08 BB09 EB02 EH04 EH05 EH06 EH13

Claims (11)

[Claims] A plasma is generated by said plasma generating means into a source gas in a casing provided with a plasma generating means, a raw material gas inlet, and a substrate support, and is placed on said substrate support. A surface processing apparatus for performing a plasma processing on a substrate surface, comprising: a plate member having one or more plasma outlets between a plasma generation region including the plasma generation unit and a substrate processing region including the substrate support. Wherein at least one of the plate members has one or more hollow discharge generation areas. 2. A method according to claim 1, further comprising: generating a plasma by said plasma generating means into a raw material gas in a casing provided with a plasma generating means, a raw material gas inlet, and a substrate support, and placing the raw material gas on the substrate support. A surface processing apparatus for performing a plasma processing on a substrate surface, comprising: a plate member having one or more plasma outlets between a plasma generation region including the plasma generation unit and a substrate processing region including the substrate support. And a hollow plasma generating electrode having one or more hollow discharge generating areas is disposed in the plasma generating area. 3. In a casing provided with a plasma generating means, a raw material gas inlet, and a substrate support, plasma is generated by the plasma generating means to convert the raw material gas into plasma, which is placed on the substrate support. A surface processing apparatus for performing plasma processing on the substrate surface, wherein the casing has one or more plasma outlets between a plasma generation area including the plasma generation means and a substrate processing area including the substrate support. A plate member having at least one plate member having at least one hollow discharge generation region, and a hollow plasma generation electrode having at least one hollow discharge generation region in the plasma generation region. A surface treatment apparatus characterized by being arranged. 4. An opening width W (1) of a minimum portion of at least one of the plasma outlets is set to a range satisfying either W (1) ≦ 5L (e) or W (1) ≦ 20X. The surface treatment apparatus according to any one of claims 1 to 3, further comprising: Here, L (e): under the desired plasma generation conditions, the source gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom, the smallest diameter atom or molecular species (active species) Mean free path of electrons with respect to seed) X: thickness of sheath layer generated under desired plasma generation conditions 5. The hollow plasma generating electrode has one or more concave portions on a surface facing plasma generated by plasma generating means, and at least one of the concave portions is the hollow discharge generating region. Item 4. The surface treatment apparatus according to item 2 or 3. 6. The hollow plasma generating electrode is a hollow body, and the electrode has at least one through hole communicating with the inside of the hollow at a portion facing the plasma generated by the plasma generating means. The surface treatment apparatus according to claim 2, wherein the through hole is formed as the hollow discharge generation area. 7. An opening width W (2) of a minimum portion of the recess or the through hole is W (2) ≦ 5L (e) or W (2) ≦ 2.
The surface treatment apparatus according to claim 5, wherein the surface treatment apparatus is set to a range satisfying any one of 0X. Here, L (e): under the desired plasma generation conditions, the source gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom, the smallest diameter atom or molecular species (active species) Mean free path of electrons with respect to seed) X: thickness of sheath layer generated under desired plasma generation conditions 8. The hollow plasma generating electrode is a hollow body, and the electrode has one or more through holes communicating with the inside of the cavity at a portion facing the plasma generated by the plasma generating means. 7. The surface treatment apparatus according to claim 2, wherein at least a part of the surface treatment area is a region where hollow discharge is generated. 9. A facing distance H in at least a part of the inside of the hollow along the formation direction of the through-hole of the hollow plasma generating electrode is in a range satisfying either H ≦ 5L (e) or H ≦ 20X. 9. The surface treatment apparatus according to claim 8, wherein the apparatus is set. Here, L (e): under the desired plasma generation conditions, the source gas species and the electrically neutral atoms and molecular species (active species) decomposed and generated therefrom, the smallest diameter atom or molecular species (active species) Mean free path of electrons with respect to seed) X: thickness of sheath layer generated under desired plasma generation conditions 10. The surface treatment apparatus according to claim 1, wherein a magnetic field is formed in the vicinity of the plasma outlet, and / or in the vicinity of the concave portion, the through hole, and / or inside the cavity. 11. The surface treatment apparatus according to claim 1, further comprising potential applying means for applying a desired potential to said substrate.