JPH0860372A - Substrate surface treatment method - Google Patents

Abstract

(57) [Summary] [Object] To provide a simple method for partially plasma-treating only a part of a substrate to perform plasma surface treatment in a desired pattern. [Structure] A metal spherical electrode 3 and a flat plate electrode 4 are arranged so as to face each other, the flat plate electrode 4 has a shape corresponding to a desired surface treatment pattern, and the spherical electrode 3 has a diameter smaller than that of the flat plate electrode 4. , A substrate 7 is installed between the electrodes, of which at least one of the electrodes, the surface facing the other electrode, is completely covered with the solid dielectric 5, and the pressure of the mixed gas of the reaction gas and the inert gas in the vicinity of the atmospheric pressure. Below, a voltage is applied to the electrodes to generate discharge plasma, the activated species in the plasma are brought into contact with the substrate surface, and the substrate is surface-treated in the same pattern as the flat plate electrode shape. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for surface-treating a substrate made of, for example, plastic, paper, metal, glass, ceramics, etc. More specifically, only a part of the substrate is partially surface-treated by plasma. , A method for performing a plasma surface treatment in a desired pattern.

[0002]

2. Description of the Related Art Conventionally, for example, plastic, paper,
As a method for controlling the wettability of the surface of a substrate such as metal, glass, ceramics or the like, a surface treatment method using low-voltage glow discharge plasma of about 0.1 to 10 Torr is widely known, and is also applied industrially. ing. In this surface treatment method, when the pressure becomes higher than the above pressure, the discharge locally becomes an arc discharge,
Since it is difficult to apply to substrates such as plastic and paper having poor heat resistance, the above pressure range is usually selected so that it can be applied to all substrates. Therefore, in order to make a vacuum (or low pressure), the processing container requires an expensive vacuum chamber, and a vacuum exhaust device is required. Further, when processing a large-area substrate for processing in a vacuum, a large-capacity vacuum container is required, and a vacuum exhaust device having a large output is also required. Therefore, there is a problem that the equipment cost becomes high. In addition, when the surface treatment of a substrate having a high water absorption rate is performed, it takes a long time to evacuate, and there is a problem that the cost of the treated product becomes high.

Therefore, in order to overcome the above-mentioned various problems, it has been proposed to reduce the cost of the apparatus and equipment and to perform discharge plasma processing under atmospheric pressure capable of processing a large area substrate. For example, Japanese Patent Application Laid-Open No. 2-15171 discloses a method of arranging a solid dielectric on the surface of an electrode.
Japanese Patent No. 8626 proposes a surface treatment method of performing discharge plasma under atmospheric pressure by a method using a fine wire type 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 porous tube having a plurality of openings to the vicinity of the substrate to perform plasma treatment.

In these conventional low-pressure and atmospheric-pressure discharge plasma processing techniques, in the case of partially surface-treating only a part of the substrate and performing the surface treatment in a pattern, for example,
JP-A-1-124847 proposes a method of applying a photosensitive resin or the like to mask unnecessary portions and removing the mask after plasma treatment (Ao Yamaoka, Hiro Morita, photosensitive resin). , Kyoritsu Publishing (1988)). However, this method has a problem that the process becomes complicated.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to partially surface-treat only a part of a substrate with a plasma,
It is to provide a simple method for performing plasma surface treatment in a desired pattern.

[0006]

According to a substrate surface treatment method of the present invention, a metal spherical electrode and a plate electrode are arranged to face each other, and the plate electrode has a shape corresponding to a desired surface treatment pattern. The diameter of the spherical electrode is smaller than that of the flat plate electrode, and at least one surface of the electrode facing the other electrode is completely covered with a solid dielectric. Under a pressure near the atmospheric pressure of the mixed gas, a voltage is applied to the electrodes to generate discharge plasma, the excited active species in the plasma are brought into contact with the substrate surface, and the substrate is formed in the same pattern as the plate electrode shape. Is surface-treated.

In the present invention, the surface treatment of the substrate mainly means the formation of a surface functional group layer, the formation of a free radical layer, the formation of a hydrophilic or water-repellent thin film, and the like.
By controlling the surface energy of the substrate and modifying the wettability and adhesiveness of the substrate, or by forming an inorganic or organic thin film on the substrate surface, chemical, mechanical, optical, electrical properties, etc. It means to give.

Examples of the reaction gas used in the present invention include a gas which is activated in discharge plasma and is brought into contact with a substrate to impart water repellency or hydrophilicity to the substrate. For example, a fluorine-containing gas is used to impart water repellency to the substrate. Examples of the fluorine-containing gas include carbon tetrafluoride (CF ₄ ), carbon hexafluoride (CF ₃ C
F ₃ ), fluorinated carbon gas such as propylene hexafluoride (CF ₃ CFCF ₃ ), halogenated carbon gas such as carbon monochloride trifluoride (CClF ₃ ), fluorinated sulfur hexafluoride (SF ₆ ), etc. Sulfur compounds; and compounds in which a part of fluorine in these compounds is replaced with hydrogen. Of these, carbon tetrafluoride and carbon hexafluoride, which are safe and do not generate toxic gases such as hydrogen fluoride, are preferable.

When imparting 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. Examples of the hydrocarbon compound include alkanes such as methane, ethane, propane, butane, pentane, and hexane; alkenes such as ethylene, propylene, butene, and pentene; alkadienes such as pentadiene and butadiene; acetylene, methylacetylene, and the like. Alkynes; aromatic hydrocarbons such as benzene, toluene, xylene, indene, naphthalene, phenanthrene; cycloalkanes such as cyclopropane and cyclohexane; cycloalkenes such as cyclopentene and cyclohexene; alcohols such as methanol and ethanol; Examples thereof include ketones such as acetone and methyl ethyl ketone; and aldehydes such as methanal and ethanal. These may be used alone or in combination of two or more kinds. Also,
In this case, oxygen gas; mixed gas of oxygen and hydrogen; water vapor;
It is also possible to use ammonia gas; nitrogen gas or the like. In addition, 50% fluorine-containing gas is added to these gases.
It may be added below, but if it is added in excess of this amount, it exhibits water repellency. The reaction gas is preferably in a gas state under a pressure near atmospheric pressure in order to perform the surface treatment with good uniformity.

Further, in order to impart chemical, mechanical, optical and electrical characteristics to the substrate, SiO ₂ , TiO ₂ and S are added.
When forming a metal oxide thin film of nO ₂ or the like, 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 inert gas used in the present invention includes:
A simple substance or a mixed gas of a rare gas such as He, Ne, Ar, and Xe is used, and it is preferable to use He, which has a long metastable excited state 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 to the substrate, the mixing ratio of the fluorine-containing gas and the inert gas is not particularly limited, but when the fluorine-containing gas is 10 volume% or more, a high voltage is applied. However, since discharge plasma is not generated, less than 10% by volume is preferable, and 0.3 to 5.0% by volume is preferable because the amount of fluorine-containing gas used is small and water repellency can be imparted.

The material and shape of the substrate used in the present invention are not particularly limited, and examples thereof include plastics, metals, glass, ceramics, papers, fibers and the like, which may be non-porous or porous. Examples of plastics that can be used include polyesters such as polyethylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polystyrene; polyamide; polyvinyl chloride; polycarbonate; polyacrylonitrile. In the case of a film, it may be stretched or unstretched. Further, it may be one which has been subjected to a known treatment such as surface cleaning or surface activation.

The present invention will be described in detail below with reference to the drawings by taking the case of imparting water repellency to the surface of a plastic substrate as an example. FIG. 1 is a schematic sectional view showing an example of a plasma generator used in the present invention. This apparatus is composed of a power supply unit 1, a processing container 2, a spherical ball electrode 3 and a flat plate electrode 4 which are arranged to face each other.

The power supply unit 1 is capable of applying a voltage having a frequency on the order of 5 to 100 kHz, and for processing a substrate having low heat resistance, a frequency of 10 to 30 kHz which has little influence on the substrate is preferable. The discharge plasma is formed by applying a voltage to the electrodes, but when the applied voltage is low, the plasma density and self-bias are small, so the process is time consuming and inefficient, and when it is high, it shifts to arc discharge. Since the behavior is exhibited, it is preferable to apply the voltage so that the electric field strength is about 5 to 40 kV / cm.

The processing container 2 has a top surface 2a and a bottom surface 2b made of stainless steel, and a side surface 2c made of Pyrex glass, and an insulator 2d is arranged between the top surface 2a and the spherical 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.

A pair of opposed upper spherical electrodes 3 and lower plate electrodes 4 are arranged in the processing container 2. The upper spherical electrode 3 is an electrode having a spherical surface, and may be a true sphere, an ellipsoid, or a hemisphere thereof, but a true sphere is preferable because a uniform surface treatment is easily performed. If the diameter of the spherical electrode 3 is larger than that of the lower flat plate electrode 4, the surface treatment cannot be performed in a pattern, so that the diameter of the spherical flat electrode 3 is made smaller than that of the lower flat plate electrode 4. The smaller the diameter of the spherical electrode 3, the sharper the pattern can be surface-treated, but if it is too small, arc discharge is likely to occur due to high voltage application, so the diameter is 1 mm.
The above is preferable. The spherical electrode 3 may be a lump or a hollow body.

The lower plate electrode 4 is shaped to match a desired processing pattern. The planar shape of the flat plate electrode 4 is arbitrary as long as it matches a desired processing pattern, and examples thereof include a shape having characters as shown in FIG. 2 and a hollow portion 4a as shown in FIG. Further, as shown in FIG. 4, a plurality of electrodes 4b may be arranged so as to form a pattern, and can be regarded as electrodes connected by connecting each electrode in parallel or in series. Can be patterned by.

The line width of the pattern is not particularly limited, but if the line interval is too narrow, the excited species in the discharge plasma reach the region where there is no pattern, and the pattern having the shape of the plate electrode cannot be formed. It is preferably 1 mm or more, and more preferably 5 mm or more.

The material of the spherical electrode and the flat plate electrode is a metal, but in this case, a multi-component metal such as stainless steel or brass, or a pure metal such as copper or aluminum may be used. In addition, the flat plate electrode 4 is a method of applying a conductive paint to a solid dielectric described later; a physical vapor deposition method such as sputtering, ion plating, or vacuum vapor deposition; a chemical vapor deposition method such as plasma CVD or a dry process such as thermal spraying. The metal thin film may be formed by the method. When the electrode is formed of a thin film, 100 Å or more is required to form a continuous film.

When applying a voltage to the electrodes, either electrode may be used, but it is safer to apply the voltage from a spherical electrode having a smaller electrode area.

In the present invention, the surface of at least one of the electrodes facing the other electrode is completely covered with the solid dielectric. In the device of FIG. 1, the solid dielectric 5 is arranged on the plate electrode 4. The solid dielectric 5 needs to be disposed on the entire surface of the facing surface of the opposing electrodes. Even if a part of the facing surface is exposed, arc discharge occurs during plasma processing. If the substrate to be treated is non-conductive, the solid dielectric may be disposed on the opposite surface of either one of the electrodes, but if the substrate is conductive such as metal, both It is necessary to dispose a solid dielectric on the electrode.

Examples of the solid dielectric 5 include plastics such as polytetrafluoroethylene (PTFE) and polyethylene terephthalate (PET); ceramics such as silica, alumina, titanium oxide, and titanate compounds such as barium titanate. Since a dielectric material having a higher relative dielectric constant can be processed with lower power, a titanium oxide and a titanic acid compound, which are ferroelectric materials, are more preferable.

The solid dielectric 5 may be in the form of a sheet or a film. However, when the thickness is thin, dielectric breakdown occurs when a voltage is applied, and arc discharge easily occurs.
A thickness of 4 mm is preferred.

The solid dielectric 5 may be formed by coating the electrode with a dielectric by a physical vapor deposition method, a chemical vapor deposition method, thermal spraying, coating or the like.

In the present invention, the plasma processing part 6 by discharge plasma is a space between the opposing electrodes. The distance between the spherical electrode and the flat plate electrode is appropriately determined according to the flow rate of the gas supplied, the magnitude of the applied voltage, the material and thickness of the solid dielectric material, the thickness of the base material, etc. The amount of gas used is inefficient and inefficient, and when it is large, the uniformity of the discharge plasma in the electrode space tends to be impaired, so 1-20 mm is preferable.

To perform plasma treatment using the apparatus shown in FIG. 1, a substrate 7 is placed on a flat plate electrode 4 on which a solid dielectric 5 is arranged, and a reaction gas is passed through a reaction gas introduction pipe 8 to permeate the reaction gas. The inert gas is supplied from the structured spherical electrode 3 to the plasma processing unit 6 through the inert gas introduction pipe 9, and the pressure is adjusted to a pressure near the atmospheric pressure of the mixed gas of the reaction gas and the inert gas.
The pressure near the atmospheric pressure as used in the present invention is specifically 100
It is up to 800 Torr, and 700 to 780 Torr is preferable in terms of cost reduction of the device and equipment.

Next, a voltage is applied to the electrodes to generate discharge plasma, and the excited active species in the plasma are brought into contact with the surface of the substrate for surface treatment of the substrate.

In FIG. 1, the sphere electrode 3 has a gas passage 3 inside in order to uniformly supply the reaction gas.
a, which is a porous electrode (specifically, the inside of the electrode is hollow and four 1 mmφ openings 3b serving as gas outlets are provided on the surface). Thus, it is preferable that the spherical electrode 3 also serves as a gas inlet and an electrode and has a porous structure in order to uniformly supply the reaction gas to the plasma processing unit 6 and perform uniform processing. Further, the inert gas may be mixed with the reaction gas and introduced from the spherical electrode 3 or the inert gas introduction pipe 9, but for uniform treatment,
As described above, it is preferable that the reaction gas and the inert gas are separated, and only the reaction gas is introduced from the spherical electrode 3 and the inert gas is introduced from the inert gas introducing pipe 9. Further, as shown in FIG. 1, the end portion of the inert gas introducing pipe 9 inside the processing container 2 has a ring shape surrounding the plasma processing portion 6 or spreading inside the plasma processing portion 6. It is preferable to form a large number of holes 9a in the ring and to supply the inert gas into the processing container 2 through the holes 9a because the inert gas and the reaction gas are easily mixed uniformly. The ring is preferably made of glass (eg Pyrex glass).

Although not shown, the reaction gas and the inert gas are preferably supplied with their flow rates controlled by a mass flow controller.

Excess reaction gas and inert gas are discharged from the gas outlet 10 of the processing container 2. Further, when the reaction gas or the inert gas is introduced into the processing container 2, it is preferable that the air remaining in the processing container 2 be exhausted from the exhaust port 11.

Further, heating or cooling of the substrate is not particularly necessary for the atmospheric pressure plasma treatment for imparting water repellency, and it is sufficient at room temperature.

The treatment time is determined by the magnitude of the applied voltage. Within the range of the applied voltage, the treatment is water repellent in about 5 seconds, and even if the treatment is carried out for a longer time, the water repellent effect is improved. No, a short treatment time is sufficient.

[0034]

Embodiments of the present invention will be described below. Example 1 Plasma generator shown in FIG. 1 (sphere electrode 3 has a diameter of 20 m
It has a spherical shape of m, is made of brass with a thickness of 3 mm, and is provided with four holes 3b having a diameter of 1 mm. The plate electrode 4 has the W shape shown in FIG. 2 and is made of stainless steel having a thickness of 3 mm.
The respective dimensions and angles in A are 100 m
m, B = 100 mm, C = 25 mm, D = 15 mm, E
= 10 mm, F = 75 degrees, G = 105 degrees), the inter-electrode distance is 5 mm, and the titanium oxide sintered body having a thickness of 2 mm and a diameter of 150 mm is used as the solid dielectric 5 on the flat plate electrode 4. , About 80), and a film of polyethylene terephthalate having a thickness of 150 μm and a thickness of 50 μm as the substrate 7 on the solid dielectric 5 (manufactured by Toray Industries Inc., trade name)
Lumirror T60) is installed and the air in the processing container 2 is adjusted to 10
The gas was exhausted from the exhaust port 11 up to Torr by a rotary pump (not shown, the same applies hereinafter).

Then, a carbon tetrafluoride gas having a gas flow rate of 10 sccm is supplied from the gas introduction pipe 8 and a gas flow rate of 990 s.
After introducing ccm of He gas into the processing container 2 through the hole 9a through the gas introducing pipe 9 and setting the atmospheric pressure to 762 Torr,
A rectangular wave having a frequency of 15 kHz was applied with a power of 5.5 kV and 34 mA and left for 15 seconds to perform surface treatment on the substrate 7. Plasma emission was observed with the application of high voltage.

Next, water drops of φ2 mm were dropped on the surface of the treated substrate at intervals of 2 mm, and the static contact angle was measured using a contact angle measuring device (trade name CA-D) manufactured by Kyowa Interface Science Co., Ltd. did. As a result, in the region irradiated with the discharge plasma, the contact angle is much higher than the contact angle of the substrate (67 degrees), and the distribution of the measurement points with the contact angle of 100 degrees or more is W-shaped similar to the shape of the flat plate electrode. It was a type pattern.

Example 2 Instead of the solid dielectric 5 in Example 1, φ150 m
m and a thickness of 2 mm, polytetrafluoroethylene (relative permittivity, about 2.4), and a voltage of 1 for plasma processing power.
Plasma treatment was performed in the same manner as in Example 1 except that the current was 7 kV and the current was 78 mA. Next, the static contact angle of the surface of the treated substrate was measured in the same manner as in Example 1. As a result, in the region irradiated with the discharge plasma, the contact angle is much higher than the contact angle (67 degrees) of the substrate, and the contact angle is 100.
The distribution of the measurement points above the degree was a W-shaped pattern similar to the shape of the plate electrode.

Example 3 The plasma generator shown in FIG. 1 (the spherical electrode 3 is the same as in Example 1. The solid dielectric 5 and the plate electrode 4 are φ15.
To a titanium oxide sintered body (relative permittivity, about 80, grade TP-3) manufactured by Fuji Titanium Co., Ltd. having a thickness of 0 mm and a thickness of 2 mm, 5
Copper was vacuum-deposited at a thickness of 0.3 μm to a square shape having four square hollow portions 4a as shown in the pattern of FIG. 3 at × 10 ⁻⁵ Torr. The respective dimensions in FIG. 3 are A = 68 mm and B = 30.
mm, C = 2 mm, D = 3 mm), the distance between the electrodes is 7 mm, and φ is used as the substrate 7 on the solid dielectric 5.
A polyethylene film having a thickness of 150 mm and a thickness of 50 μm was installed, and the air in the processing container 2 was exhausted from the exhaust port 11 to 10 Torr by a rotary pump (not shown; the same applies hereinafter).

Next, a mixed gas of a carbon tetrafluoride gas having a gas flow rate of 3 sccm and an oxygen gas having a gas flow rate of 7 sccm is supplied from the gas introducing pipe 8, and a He gas having a gas flow rate of 990 sccm is passed through the gas introducing pipe 9 from a hole 9a through a processing container. Introduced in 2,
After setting the atmospheric pressure to 757 Torr, a rectangular wave having a frequency of 20 kHz was applied with power of 7 kV and 41 mA and left for 60 seconds to surface-treat the substrate 7. Plasma emission was observed with the application of high voltage.

Next, the static contact angle of the surface of the treated substrate was measured in the same manner as in Example 1. As a result, in the area irradiated with the discharge plasma, the contact angle is much lower than the contact angle of the substrate (88 degrees), and the distribution of the measurement points at the contact angle of 45 degrees or less is similar to that of the plate electrode. Was becoming.
Therefore, it was found that the pattern was hydrophilized in the same pattern as that of the plate electrode.

Example 4 Plasma generator shown in FIG. 1 (sphere electrode 3 has a diameter of 10 m
m spherical shape, made of stainless steel with a thickness of 3 mm, φ1 m
Four holes 3b of m are provided. As the solid dielectric 5 and the plate electrode 4, a quartz dielectric having a diameter of 140 mm and a thickness of 2 mm (relative permittivity: 4.5) is 2 × 10 ⁻⁵ Torr.
With copper 0.2 μm thick, as shown in FIG.
Vacuum deposition is performed so that four 4 mm square electrodes 4b are arranged at an interval of 2 mm, and then lead wires are brazed in parallel between each isolated electrode 4b. In addition, each dimension in FIG. 4 is A = 30 m
m, B = 2 mm), the distance between the electrodes is 3 mm, a polyethylene film having a thickness of 140 μm and a thickness of 50 μm is installed as the substrate 7 on the solid dielectric 5, and the air in the processing container 2 is adjusted to 10 Torr. The gas was exhausted from the exhaust port 11 with a rotary pump (not shown, the same applies hereinafter).

Next, a mixed gas of nitrogen gas having a gas flow rate of 5 sccm and He gas having a gas flow rate of 995 sccm is introduced into the processing container 2 through the hole 9a through the gas introduction pipe 9,
After setting the atmospheric pressure to 57 Torr, a rectangular wave having a frequency of 15 kHz was applied at a power of 5.5 kV and 34 mA and left for 60 seconds to surface-treat the substrate 7. Plasma emission was observed with the application of high voltage.

Next, the static contact angle of the surface of the treated substrate was measured in the same manner as in Example 1. As a result, in the area irradiated with the discharge plasma, the contact angle is much lower than the contact angle of the substrate (88 degrees), and the distribution of the measurement points at the contact angle of 45 degrees or less is similar to that of the plate electrode. Was becoming.
Therefore, it was found that the pattern was hydrophilized in the same pattern as that of the plate electrode. However, there were about 9 points with a contact angle of about 60 degrees.

Comparative Example 1 Example 1 was repeated except that the solid dielectric 5 was not arranged on the plate electrode 4 and the plasma treatment pressure was 0.1 Torr instead of 762 Torr.
The surface was treated in the same manner as in. The discharge plasma was used in Example 1
It showed a broader shape compared to. Next, the static contact angle of the surface of the treated substrate was measured in the same manner as in Example 1. As a result, in the region irradiated with the discharge plasma, a contact angle of 100 degrees or more, which was much higher than the contact angle of the substrate (67 degrees), was shown. It did not have a W-shaped pattern similar to the shape.

[0045]

The structure of the surface treatment method for a substrate of the present invention is as described above, and is for performing a plasma surface treatment in a desired pattern by partially surface-treating only a part of the substrate with plasma. , Provides a simple method. In addition, compared to the conventional method of surface treatment of plastic etc. by low-pressure glow discharge plasma, no special equipment and facilities for vacuum formation are required, and no special operation for that is required, resulting in cost reduction effect. It is excellent and easy to handle. Therefore, it can be used for adhesion of plastics, metals, ceramics, etc., coating fields, etc., and its ripple effect is great.

[Brief description of drawings]

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

FIG. 2 is a plan view showing the shape of a plate electrode used in Examples.

FIG. 3 is a plan view showing the shape of a plate electrode used in Examples.

FIG. 4 is a plan view showing how to arrange the plate electrodes used in the examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply part 2 Processing container 2a Upper surface 2b Bottom surface 2c Side surface 2d Insulator 3 Ball electrode 3a Gas passage 3b Open hole 4 Plate electrode 5 Solid dielectric 6 Plasma processing part 7 Substrate 8 Reactive gas introduction pipe 9 Inert gas introduction pipe 9a Hole 10 gas outlet 11 exhaust port

Claims (1)

[Claims] 1. A metallic spherical electrode and a flat plate electrode are arranged to face each other, the flat plate electrode has a shape corresponding to a desired surface treatment pattern, and the spherical electrode has a diameter smaller than that of the flat plate electrode. The substrate is placed between the electrodes whose surface facing the other electrode is completely covered by the solid dielectric, and the electrodes are placed under the pressure near the atmospheric pressure of the mixed gas of the reaction gas and the inert gas. A surface treatment method for a substrate, characterized in that a discharge plasma is generated by applying a voltage, the activated species in the plasma are brought into contact with the substrate surface, and the substrate is surface-treated in a pattern similar to a plate electrode shape. .