JP2957068B2 - Substrate surface treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a surface of a substrate made of, for example, plastic, paper, metal, glass, ceramics, etc., and more particularly, to a method for treating a surface of a substrate using plasma near atmospheric pressure.

[0002]

2. Description of the Related Art Conventionally, for example, plastic, paper,
As a method for controlling wettability and surface modification of the surface of a substrate such as a metal, a glass, and a ceramic, a surface treatment method using a low-pressure glow discharge plasma of about 0.1 to 10 Torr is widely known, and is applied industrially. ing. In this surface treatment method, when the pressure becomes higher than the above-mentioned pressure, the discharge is localized and shifts to arc discharge,
The above pressure range is usually selected so that it can be applied to any substrate because it becomes difficult to use the substrate for a substrate such as plastic or paper having poor heat resistance. For this reason, in addition to the necessity of applying a vacuum (or low pressure), the processing vessel requires an expensive vacuum chamber and a vacuum exhaust device. Further, when processing is performed on a large-area substrate because the processing is performed in a vacuum, a large-capacity vacuum container is required, and a large-sized vacuum evacuation device is required. Therefore, there has been a problem that the equipment cost is high. In addition, when performing surface treatment on a substrate having a high water absorption, there is a problem that it takes a long time to make a vacuum and the cost of a processed product increases.

[0003] In order to overcome the above-mentioned various problems, glow discharge plasma under atmospheric pressure has been proposed which can reduce the cost of equipment and facilities and can process large-area substrates. For example, Japanese Patent Application Laid-Open No. Hei 2-15171 discloses a method in which a solid dielectric is provided on an electrode surface.
No. 48626 proposes a surface treatment method for performing glow discharge plasma under atmospheric pressure by a method using a thin wire electrode. In these proposals, a method is used in which a mixed gas of an inert gas mainly containing helium and a reaction gas is supplied from a perforated tube having a plurality of apertures to a plasma region near a substrate. In addition, there is a problem that it is difficult to uniformly diffuse and supply a gas when the substrate has a large area.

[0004] Japanese Patent Application Laid-Open No. 2-739779 discloses that
A substrate is provided between two opposing electrodes, one of which is a metal electrode capable of supplying a surface treatment reaction gas having a perforated plate-shaped solid dielectric disposed on the opposing surface, and the other is a metal electrode. An inert gas and a reaction gas are supplied to the space between them, and a voltage is applied to the electrodes under a pressure near the atmospheric pressure to generate glow discharge plasma, and the active species excited by the plasma are brought into contact with the substrate surface. Accordingly, a thin film forming method has been proposed. However, this method has a problem in that the ratio of the gas actually used for the surface treatment among the reaction gases is small, and a large amount of unused gas is generated, resulting in poor use efficiency (yield) of the reaction gas. there were.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a reaction gas which is uniformly diffused and supplied to a plasma region, has a high use efficiency, and has a high atmospheric pressure. An object of the present invention is to provide a method for treating a surface of a substrate by a glow discharge plasma method.

[0006]

According to a method of treating a surface of a substrate of the present invention, a first solid dielectric is provided on one surface of a metal electrode, and a porous metal electrode is provided opposite to the first solid dielectric. The porous metal electrode is capable of supplying a reaction gas,
Between the solid dielectric and the porous metal electrode, wherein the side surface is a space covered with the second solid dielectric,
Placing the substrate in the space covered by the second solid dielectric,
In addition to supplying an inert gas to the substrate, a reaction gas is supplied to the substrate through the porous metal electrode, and a voltage is applied to the electrode under a pressure near the atmospheric pressure to generate a glow discharge plasma, and the plasma generates The excited active species are brought into contact with the substrate surface.

In the present invention, the surface treatment of the substrate mainly includes forming a surface functional group layer, forming a free radical layer, and forming a hydrophilic or water-repellent thin film.
By controlling the surface energy of the substrate to improve the wettability and adhesion of the substrate, or by forming an inorganic or organic thin film on the substrate surface, the substrate can be chemically, mechanically, optically, electrically, etc. Is given.

In the present invention, the surface treatment is performed by supplying a reaction gas selected according to the purpose of the surface treatment from the porous metal electrode to the plasma region. As the reaction gas, for example, when fluorine is chemically bonded to the substrate surface to lower the surface energy and impart water repellency, a fluorine-containing gas is used. As the fluorine-containing gas, carbon tetrafluoride (C
F ₄ ), saturated carbon fluoride gas such as carbon hexafluoride (C ₂ F ₆ ), and sulfur fluoride gas such as sulfur hexafluoride (SF ₆ ).

Conversely, when the surface energy is increased to impart hydrophilicity, a hydrocarbon compound gas is used to form a layer having a functional group such as a carbonyl group, a hydroxyl group or an amino group on the surface. use. Examples of the hydrocarbon compound include alkanes such as methane, ethane, propane, butane, pentane and hexane; ethylene,
Alkenes such as propylene, butene and pentene; alkadienes such as pentadiene and butadiene; acetylene;
Alkynes such as methylacetylene; aromatic hydrocarbons such as benzene, toluene, xylene, indene, naphthalene and phenanthrene; cycloalkanes such as cyclopropane and cyclohexane; cycloalkenes such as cyclopentene and cyclohexene; Alcohols; ketones such as acetone and methyl ethyl ketone; aldehydes such as methanal and ethanal; and the like, which may be used alone or in combination of two or more. In this case, it is also possible to use oxygen gas, a mixed gas of oxygen and hydrogen, water vapor, ammonia gas, or the like.

In order to impart chemical, mechanical, optical, and electrical characteristics to the substrate, SiO ₂ , TiO ₂ , S
When a metal oxide thin film such as nO ₂ is formed, a gas or vapor of a metal organic compound such as a metal hydride gas, a metal halide gas, or a metal alcoholate is used.

The material and shape of the substrate used in the present invention are not particularly limited, and examples thereof include plastic, metal, glass, ceramic, paper, and fibers. The substrate may be dense or porous. Examples of the plastic include polyesters such as polyethylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polystyrene; polyamide;
Polycarbonate; films or sheets of polyacrylonitrile or the like can be used. In the case of a film, it may be stretched or unstretched. Further, a material which has been subjected to a known treatment of surface cleaning and surface activation may be used.

Hereinafter, the present invention will be described in detail with reference to the drawings, taking as an example the case where water repellency is imparted to the surface of a plastic. In FIGS. 1 to 3, components corresponding to each other are denoted by the same reference numerals. FIG. 1 is a schematic sectional view showing an example of a plasma generator used in the present invention. This apparatus comprises a power supply unit 1, a processing vessel 2, opposing porous metal electrodes 3 and metal electrodes 4, and a plasma processing unit 5 between two opposing electrodes. The power supply unit 1 is capable of applying a voltage of a frequency on the order of kHz, and a frequency of 10 to 30 kHz is preferable for imparting water repellency. Plasma formation is performed by applying a high voltage.However, if the applied voltage is too low, the plasma density and self-bias become small, so the processing takes time and is inefficient. , Electric field strength 5-40
It is preferable to apply a voltage so as to be about kV / cm.

The processing vessel 2 has a top surface 2a and a bottom surface 2b made of stainless steel, a side surface 2c made of Pyrex glass, and an insulator 2d disposed between the top surface 2a and the porous metal electrode 3. The material of the processing container 2 is not limited to this, and all may be made of glass or plastic, or may be made of metal such as stainless steel or aluminum as long as it is insulated from the electrodes.

In the present invention, the plasma processing unit 5 using glow discharge plasma is a space between the first solid dielectric and the porous metal electrode. At least one of the opposing electrodes is a metal electrode having a first solid dielectric disposed on the opposing surface,
At least one is a porous metal electrode capable of supplying a reaction gas. That is, there are the following five cases as a configuration of two opposing electrodes. Metal electrode with solid dielectric material-porous metal electrode Metal electrode with solid dielectric material-porous metal electrode with solid dielectric material Metal electrode-porous metal electrode with solid dielectric material Solid metal with porous dielectric material Electrode-Porous metal electrode Porous metal electrode with solid dielectric-Porous metal electrode with solid dielectric

FIG. 1 shows the above configuration.
The two opposing electrodes include a porous metal electrode 3 and a metal electrode 4 on which a first solid dielectric 6 is disposed. The porous metal electrode capable of supplying a reaction gas is a porous metal electrode that also serves as a gas supply pipe. As shown in the porous metal electrode 3 in FIG.
a is provided, and the surface facing the other electrode is a porous surface having a large number of apertures 3b serving as gas outlets. The porous metal electrode 3
And the metal electrode 4 are connected such that one is on the anode side and the other is on the cathode side. Either of the two opposing electrodes having the above configurations may be located at the upper or lower part.

A plastic substrate 7 is placed on the first solid dielectric 6. In addition, if the surface treatment of only one side of the substrate is necessary, ~ of the above-mentioned electrode configurations is selected,
If simultaneous processing on both sides is necessary, the configuration of or is selected.

The material of the first solid dielectric 6 is ceramic; glass; plastic such as polytetrafluoroethylene or polyethylene terephthalate, and is appropriately selected depending on the reactivity with the reaction gas. For example,
Since glass is easily melted by carbon tetrafluoride plasma, it is difficult to use in the case of imparting water repellency. The shape may be a sheet or a film, but if it is too thin, dielectric breakdown occurs when a high voltage is applied, causing arc discharge,
On the other hand, if it is too thick, it becomes difficult to discharge, so
mm is preferred. In the arrangement of the solid dielectric, if there is a part that is not disposed on a part of the facing surface, an arc discharge occurs in that part, and therefore, it is necessary to dispose the solid dielectric on the entire surface of the facing surface.

The distance between the opposing first solid dielectric and the porous metal electrode is appropriately determined depending on the gas flow rate of the reaction gas, the magnitude of the applied voltage, the thickness of the processing substrate, and the like. In this case, the uniformity of gas diffusion in the space between the first solid dielectric and the porous metal electrode is impaired, and the amount of unused reaction gas increases, which is inefficient.
mm is preferred.

As the arrangement structure of the opposing first solid dielectric and porous metal electrode, in addition to the parallel plate type as shown in FIG. 1, a coaxial cylinder type, a cylinder-to-plate type, and a hyperboloid-to-plate type The tip of one of the electrodes may be in the form of a plurality of pipes as shown in FIG.
As shown in the figure, a plurality of fine lines may be used.

The material of the metal electrode may be a multi-component metal such as stainless steel or brass, or a pure metal such as copper or aluminum.

In the present invention, the side surface between the opposing first solid dielectric and the porous metal electrode is covered with the second solid dielectric 8. As the material of the second solid dielectric, the first solid dielectric described above is used.
Although the same material as that used for the solid dielectric of the first embodiment may be used, the material may be the same as or different from that of the first solid dielectric. As a method of covering the side surface between the opposing first solid dielectric and the porous metal electrode, as shown in FIG. 1, when the second solid dielectric has a considerable thickness like a sheet, the second solid dielectric has a second thickness. Since the surface of the substrate that comes into contact with the solid dielectric cannot be processed, the sheet is cut out larger than the processing area of the substrate to be processed so that the processing area of the substrate can enter the hollowed interior. A method of sandwiching the sheet between the opposing first solid dielectric and the porous metal electrode. When the second solid dielectric is a film, as shown in FIG. 2 or FIG. There is a winding method.

The more the side face between the first solid dielectric and the porous metal electrode is closed by the second solid dielectric, the more efficiently the reaction gas is used. When gas is supplied to the processing vessel 2 from different inlets, it is necessary to provide a sufficient gap for diffusing the inert gas into the plasma processing unit 5. As a method of forming the gap, for example, a method of making a small hole in the side surface of the second solid dielectric 8, and when the second solid dielectric 8 is the above-described sheet, providing irregularities on the upper surface or the lower surface of the sheet And the like.

In the present invention, as described above, the substrate 7 is provided between the first solid dielectric and the porous metal electrode,
An inert gas and a reaction gas are supplied to the space, and a voltage is applied to the electrode under a pressure near the atmospheric pressure to generate glow discharge plasma, and active species excited by the plasma are brought into contact with the substrate surface.

The pressure near the atmospheric pressure is 100 to 7
70 Torr, preferably atmospheric pressure in consideration of cost reduction of equipment and facilities.

As the inert gas, He, Ne, Ar,
A simple gas or a mixed gas of a rare gas such as Xe or a nitrogen gas is used, but it is preferable to use He which has a long metastable life and is advantageous for exciting and decomposing the reaction gas. When an inert gas other than He is used, it is necessary to mix an organic vapor such as acetone or methanol or a hydrocarbon gas such as methane or ethane within 2% by volume.

When imparting water repellency, a fluorine-containing gas is used as the reaction gas. The mixing ratio of the inert gas and the fluorine-containing gas is such that the fluorine-containing gas concentration is about 1
If it is 0% by volume or more, glow discharge plasma is hardly generated even when a high voltage is applied. Therefore, it is preferably about 10% by volume or less. More preferably, it is between 5.0% by volume.

The reaction gas is flow-controlled by the mass flow controller and is introduced into the plasma processing section 5 from the gas inlet 9 of the porous metal electrode 3. The inert gas is introduced into the processing vessel 2 from the gas introduction port 10a of the gas introduction pipe 10 with the flow rate controlled by a mass flow controller. As shown in FIG. 1, the gas introduction pipe 10 is configured such that a portion inside the processing container 2 surrounds the periphery of the plasma processing unit 5, and a number of holes are formed in an inner peripheral surface of the surrounded portion. The hole may be used as the gas outlet 10b, but the inert gas is almost uniformly diffused into the plasma processing section 5 even if not configured in this way. Further, an inert gas and a reaction gas may be mixed and introduced from the gas inlet 9. However, in order to uniformly impart water repellency, only the reaction gas is introduced from the gas inlet 9. Is preferred. Unused reaction gas and inert gas are discharged from the gas discharge port 11 of the processing container.

Heating and cooling of the substrate are not particularly required for atmospheric pressure plasma treatment for imparting water repellency, and can be sufficiently performed at room temperature.

The processing time is determined by the magnitude of the applied voltage. In the range of the applied voltage, the water repellency is about 5 seconds, and the water repellency is improved even if the processing is performed for a longer time. A short processing time is sufficient.

[0030]

Embodiments of the present invention will be described below. Example 1 The plasma generator shown in FIG.
mm, and a polytetrafluoroethylene having a diameter of 90 mm and a thickness of 1 mm is disposed thereon as the first solid dielectric 6. The porous metal electrode 3 is a disc-shaped 80 mm × 80 mm × 100 μm-thick polyester film (trade name “Lumirror S10” manufactured by Toray Industries, Inc.) as the substrate 7 in the form of a disc having a diameter of 80 mm on the opposite surface. A corrugated plate having an outer diameter of 80 mm, an inner diameter of 70 mm, and a thickness of 5 mm as a second solid dielectric 8 covering a side surface between the opposing first solid dielectric and the porous metal electrode on a substrate 7 on the substrate 6. A polytetrafluoroethylene sheet is placed (because the sheet is corrugated, there is a slight gap between the substrate 7 and the second solid dielectric 8 and between the porous metal electrode 3 and the second solid dielectric 8). Is formed), and the distance between the substrate 7 and the porous metal electrode 3 is set to about 5
After setting to 1 mm, the oil was exhausted from the exhaust port 12 by an oil rotary pump (not shown; the same applies hereinafter) until 1 Torr.

Next, a carbon tetrafluoride gas having a gas flow rate of 2 sccm was supplied from the gas inlet 9 through the gas inlet 9, and 198 sccm of H 4 gas was supplied.
e gas is introduced into the processing vessel 2 from the gas inlet 10a,
After the atmospheric pressure was set to 760 Torr, a rectangular wave having a frequency of 15 kHz was applied with a power of 6.2 kV and 28 mA and left for 10 seconds to perform a surface treatment on the substrate. Plasma emission was observed with the application of a high voltage. At that time, the voltage-current characteristics were observed with an oscilloscope. As a result, the pulse characteristics shown in FIG. 4 were obtained. It turned out to be a pulse discharge.

Next, the contact angle of the processed surface of the processed substrate with respect to pure water was measured. As a result, it was clear that the circle region having a diameter of 60 mm showed a water repellency of 100 to 108 degrees. The contact angle of the used substrate was 65 degrees. In addition, as a result of analyzing the treated surface by X-ray electron spectroscopy, it was found that 67% of the atomic ratio of fluorine was chemically bonded to the surface. Example 2 In Example 1, the thickness of the second solid dielectric 8 was 5 m.
m, and the distance between the substrate 7 and the porous metal electrode 3 is about 5 m.
m, a corrugated polytetrafluoroethylene sheet having a thickness of 10 mm was used, and the distance between the substrate 7 and the porous metal electrode 3 was set to about 10 mm.
, And the surface treatment of the substrate was performed in the same manner as in Example 1 except that the gas flow rate, the electric power, and the processing time in Example 1 were changed as described below. Gas flow 6s
ccm 4 fluorocarbon gas from the gas inlet 9
He gas of 194 sccm was introduced into the processing chamber 2 from the gas inlet 10a, and the atmospheric pressure was set to 760 Torr.
A rectangular wave with a frequency of 15 kHz is converted to 10.0 kV, 35 mA
The substrate was subjected to a surface treatment by applying the same power and left for 10 minutes.

As a result, plasma emission was observed with the application of a high voltage, and the contact angle of the treated surface of the treated substrate with pure water was 100 to 108 degrees in a circular region having a diameter of 60 mm, and the substrate was made water-repellent. It was clear that. Also,
The treated surface was analyzed by X-ray electron spectroscopy.
It was found that 5% of the fluorine was chemically bonded to the surface.

Example 3 An electrode having the structure shown in FIG. 2 in which the tip of the porous metal electrode 3 has a plurality of pipes (the opposing surface of the porous metal electrode is a circle having a diameter of 80 mm and has a length of 80 10mm, outer diameter 2
mm, and a pipe 3c having an inner diameter of 1 mm protrudes).
The metal electrode 4 is a disk type having a diameter of 85 mm, and the first
Using a device in which polytetrafluoroethylene having a diameter of 90 mm and a thickness of 1 mm was disposed as the solid dielectric 6 of the above, and a 85 mm × 85 mm × 12 μm thick polyamide film (trade name “Kapton” manufactured by Toray Industries, Inc.) was used as the substrate 7. First
After the outer peripheral surface of the porous metal electrode 3 is covered with a 100 μm-thick polytetrafluoroethylene film, which is a second solid dielectric 8, in a skirt shape (the surface facing the porous metal electrode 3). And the distance from the substrate 7 to the tip of the pipe 3c of the porous metal electrode 3 was set to about 5 mm, and then 1 Torr.
The oil was exhausted by an oil rotary pump to r. Next, gas flow rate 4s
ccm 4 fluorocarbon gas from the gas inlet 9
A mixed gas of 194 sccm Ar gas and 2 sccm acetone vapor was introduced into the processing vessel 2 from the gas inlet 10a, and the pressure was adjusted to 760 Torr atmospheric pressure.
A rectangular wave of 1 Hz was applied at a power of 12.5 kV and 38 mA, and the substrate was left for 10 seconds to perform a surface treatment on the substrate. Plasma emission was observed with the application of high voltage.

The contact angle of the treated surface of the substrate after treatment to pure water was 100 to 108 degrees in a circular region having a diameter of 85 mm, and it was clear that the substrate was water-repellent. The contact angle of the used substrate was 63 degrees. Further, as a result of analyzing the treated surface by X-ray electron spectroscopy, it was found that 55% of fluorine in an atomic ratio was chemically bonded to the surface.

Comparative Example 1 The polytetrafluoroethylene sheet as the second solid dielectric 8 covering the space between the first solid dielectric and the porous metal electrode was not placed on the substrate 7 in the first embodiment. And carbon tetrafluoride gas from the gas inlet 9 and He gas
Instead of introducing the gas into the processing container 2 from the gas inlet 10a, a carbon tetrafluoride gas and He gas were mixed and introduced into the processing container 2 from the gas inlet 10a. The surface treatment of the substrate was performed in the same manner as in 1.

As a result, plasma emission was observed with the application of a high voltage, and the contact angle of the treated surface of the treated substrate with pure water showed a contact angle of 30 ° or less on all treated surfaces, indicating that the substrate was water-repellent. I knew it wasn't. In addition, as a result of analyzing the treated surface by X-ray electron spectroscopy, it was found that only about 5% of the fluorine in the atomic ratio was chemically bonded to the surface.

COMPARATIVE EXAMPLE 2 Instead of mixing carbon tetrafluoride gas and He gas in Comparative Example 1 and introducing them into the processing vessel 2 through the gas inlet 10a, mixing of carbon tetrafluoride gas and He gas was performed. The surface treatment of the substrate was performed in the same manner as in Comparative Example 1, except that the gas was introduced into the processing container 2 from the gas inlet 9. As a result, plasma emission was observed with the application of a high voltage, and the contact angle of the treated surface of the treated substrate with pure water was 35 to 45 degrees on all treated surfaces, indicating that the substrate was not water-repellent. I understood. In addition, as a result of analyzing the treated surface by X-ray electron spectroscopy, it was found that only about 20% of fluorine was chemically bonded to the surface at an atomic ratio.

Example 4 Instead of introducing the carbon tetrafluoride gas from the gas inlet 9 and the He gas into the processing vessel 2 from the gas inlet 10a in the first embodiment, instead of introducing the carbon tetrafluoride gas into the processing vessel 2, The surface treatment of the substrate was performed in the same manner as in Example 1 except that He gas was mixed and introduced into the container from the gas inlet 9. As a result, the contact angle of the processing surface of the processed substrate with pure water is
It varied between 45 and 108 degrees. Also, the processing surface is represented by X
As a result of analysis by a line electron spectroscopy, 20 to 60% by atom ratio of chemically bonded fluorine was confirmed.

Example 5 A surface treatment was performed in the same manner as in Example 1, except that a filter paper was used instead of using a polyester film as the substrate. As a result, the contact angle of the treated surface of the treated substrate to pure water was 100 to 108 degrees in a circular region having a diameter of 60 mm, and it was clear that the substrate was water-repellent.

Embodiment 6 FIG. 3 in which the tip of the porous metal electrode 3 has a plurality of fine lines.
(The opposite surface of the porous metal electrode has a diameter of 8
0mm circular, 10mm long thin line 3d is 10mm
Projecting at a density of present / cm ² and in that), the metal electrode 4 is a circular plate having a diameter of 85 mm, diameter 90mm thereon as the first solid dielectric 6, the polytetrafluoroethylene having a thickness of 1mm distribution Using the installed device, 85
A polyester film of mm × 85 mm × 100 μm thickness (trade name “Lumirror S10” manufactured by Toray Industries, Inc.) is placed on the first solid dielectric 6, and then the outer peripheral surface of the porous metal electrode is covered with the second solid dielectric 8. After covering in a skirt shape with a certain 100 μm-thick polytetrafluoroethylene film (the length from the opposing surface of the porous metal electrode 3 to the tip of the skirt was set to 20 mm), the thin wire 3d of the substrate 7 and the porous metal electrode 3 was formed.
Was set to about 5 mm, and then exhausted with an oil rotary pump to 1 Torr.

Next, a mixed gas of carbon tetrafluoride gas having a gas flow rate of 1 sccm and oxygen having a flow rate of 2 sccm was introduced into the gas inlet 9.
197 sccm of He gas was introduced into the gas inlet 1
0a, introduced into the processing vessel 2 and set to an atmospheric pressure of 760 Torr, and then a rectangular wave having a frequency of 15 kHz
V was applied with a power of 28 mA and left for 30 seconds to perform a surface treatment of the substrate. Plasma emission was observed with the application of high voltage. The contact angle of the treated surface of the substrate after treatment with pure water was 15 degrees in a circular region having a diameter of 85 mm, indicating that the substrate was hydrophilic.

[0043]

The structure of the present invention is as described above. Compared with the conventional surface treatment method for plastics and the like by low-pressure glow discharge plasma, no special vacuum forming apparatus and equipment is required. No special operation is required for this, and the cost reduction effect is excellent, and the handling is easy. Further, since the reaction gas is uniformly diffused and supplied to the plasma region, it is possible to increase the processing area, which is a problem of the atmospheric pressure plasma, and to efficiently use the reaction gas. Further, both surfaces of the substrate can be simultaneously surface-treated, and the area of the processed surface can be designated, so that the industrial ripple effect will be great in the future. Furthermore, the present invention can be easily developed for forming a thin film.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one example of a plasma generator used for a surface treatment method of the present invention.

FIG. 2 is a schematic cross-sectional view showing a modified example of the structure of the porous metal electrode and a method of using the modified example.

FIG. 3 is a schematic sectional view showing a modified example of the structure of the porous metal electrode and a method of using the modified example.

FIG. 4 is a graph showing pulse characteristics of a voltage-current according to the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply 2 Processing container 2a Top surface 2b Bottom surface 2c Side surface 2d Insulator 3 Porous metal electrode 3a Gas passage 3b Opening 3c Pipe 3d Fine wire 4 Metal electrode 5 Plasma processing unit 6 First solid dielectric 7 Substrate 8 Second solid Dielectric 9 Gas inlet 10 Gas inlet pipe 10a Gas inlet 10b Gas outlet 11 Gas outlet 12 Exhaust port

Claims (1)

(57) [Claims] A first solid dielectric is provided on one surface of a metal electrode, a porous metal electrode is provided facing the first solid dielectric, and the porous metal electrode is capable of supplying a reaction gas.
The substrate is placed in the space covered with the second solid dielectric of the plasma generator, the side of which is a space covered with the second solid dielectric between the first solid dielectric and the porous metal electrode. Install and supply an inert gas to the substrate, supply a reaction gas to the substrate through the porous metal electrode, and apply a voltage to the electrode under a pressure near atmospheric pressure to generate glow discharge plasma. And a method of treating a surface of a substrate, wherein active species excited by the plasma are brought into contact with the surface of the substrate.