JP2009041085A - Carbon film deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon film deposition method by which the generation of fine powder is suppressed by a simple process, and a carbon film of high quality having adhesion with a base material, surface smoothness, scratch resistance and low friction properties is deposited. <P>SOLUTION: The carbon film deposition method is provided for depositing the carbon film on the base material using plasma discharge under atmospheric pressure or under pressure in the vicinity of atmospheric pressure. The method comprises: a step where a discharge gas is introduced into a discharge space and excited; a step where the excited discharge gas and a raw material gas containing carbon are mixed in the vicinity of the base material outside the discharge space to be a secondarily excited gas; a thin film deposition step 1 where the base material is exposed to the secondarily excited gas thereby depositing the carbon film on the base material; and a step 2 where the carbon film deposited by the thin film deposition step 1 is exposed to an excitation gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a carbon film forming method excellent in adhesion to a substrate, surface roughness characteristics, scratch resistance, friction characteristics and smoothness.

  In recent years, methods for applying functional films to the surface of substrates have been developed for the purpose of imparting strength, wear resistance, frictional resistance reduction, chemical stability, and oxygen and moisture shielding properties to various substrates. .

  As one of functional films having these characteristics, a carbon film (hard carbon film) has attracted attention. Examples of the carbon film include an amorphous carbon film, a hydrogenated amorphous carbon film, a tetrahedral amorphous carbon film, a nitrogen-containing amorphous carbon film, a metal-containing amorphous carbon film, and the like. (DLC) film. This diamond-like carbon film is also called i-carbon film, amorphous carbon film or hard carbon film, has a very smooth surface, excellent mechanical, electrical and chemical properties, and Since it can be formed at a low temperature, it is attracting attention as a highly functional film.

  On the other hand, in an image forming apparatus applied to a copying machine, a printer, a facsimile, etc. using an electrophotographic system, a toner image is primarily transferred from a first toner image carrier, and the transferred toner image is carried. An image forming apparatus having an intermediate transfer member that secondarily transfers a toner image onto a recording sheet or the like is known.

  As such an intermediate transfer member, Japanese Patent Application Laid-Open No. 9-212004 discloses that the surface of the intermediate transfer member is coated with silicon oxide, aluminum oxide or the like to improve the releasability of the toner image and to record paper or the like. There are proposals for improving the transfer efficiency.

  However, it is almost impossible for an image forming apparatus having an intermediate transfer body to transfer a toner image at the time of secondary transfer at the present time. For example, cleaning is performed by scraping off toner remaining on the intermediate transfer body from the intermediate transfer body with a blade. I need a device.

  The intermediate transfer member described in the above patent document has a problem that the toner transfer rate at the time of secondary transfer is not sufficient and the durability is not sufficient, and silicon oxide is deposited by vapor deposition, and aluminum oxide or the like is formed by sputtering. Therefore, there is a problem that a large facility such as a vacuum apparatus is required.

  As a method for forming a carbon film on the substrate surface as described above, a known thinning method such as a vacuum deposition method, a sputtering method, a plasma CDV method, or the like is known. For example, a method of forming an amorphous carbon thin film using a vacuum parallel plate type high-frequency plasma CVD apparatus is disclosed (for example, see Patent Document 1). However, the method described in Patent Document 1 has a very low production efficiency because the deposition rate of the carbon film is low and a special large-scale apparatus such as a vacuum apparatus is required. In contrast, a method for forming a carbon film under atmospheric pressure conditions instead of a vacuum apparatus has been studied. For example, a method of forming a hydrocarbon compound film (DLC) on the outer surface or inner surface of a plastic bottle using an atmospheric pressure low temperature plasma method is disclosed (for example, refer to Patent Document 2). However, in the method described in Patent Document 2, an expensive helium gas is used as the discharge gas, and it is difficult to say that the adhesion to the substrate is sufficient. In addition, a method of forming a hard carbon film on a silicon wafer by a torch method under atmospheric pressure conditions (for example, see Non-Patent Document 1). However, the method described in Non-Patent Document 1 is difficult to apply to film formation using a resin film or the like having a problem in heat resistance because the substrate temperature at the time of carbon film formation is high. The film forming speed is low, the area that can be formed once is small, and expensive helium or the like is used as a discharge gas, so that the production efficiency is low.

  Further, an excitation gas is formed by a discharge gas and a raw material gas in a discharge space that is applied between opposing electrodes under atmospheric pressure conditions and is cut off from the atmosphere, and the excitation gas is exposed to the substrate outside the discharge space. A method of forming a hard carbon film or the like is disclosed (for example, see Patent Document 3). According to this method, it is said that a homogeneous thin film can be formed by eliminating the influence of the atmosphere during film formation, particularly the influence of impurities such as oxygen on the formed film. However, in the method described in Patent Document 3, since a raw material gas containing a thin film forming compound is supplied to the discharge space, the thin film forming compound is directly exposed to the discharge space, so that it is difficult to suppress vapor phase growth. As a result, a carbon film containing pinholes was formed by fine powder or the like grown in the discharge space, and vapor phase growth could not be completely suppressed.

In addition, a raw material gas containing a hard carbon film forming material is supplied between the counter electrodes under atmospheric pressure conditions, and a thin film is formed by bringing the base material into the discharge space into the raw material gas excited by plasma discharge. An apparatus for manufacturing a transfer body is disclosed (for example, see Patent Document 4). According to this method, it is possible to obtain an intermediate transfer body having high transferability and excellent cleaning properties and durability, but there are still problems in adhesion and friction properties with the substrate. is the current situation.
JP-A-5-273425 JP 2001-158415 A JP-A-5-44041 International Publication WO2006 / 129543 Specification Japan Journal of Applied Physics Vol. 44, no. 52, 2005, pp. L1573-L1575

  The present invention has been made in view of the above problems, and its purpose is to suppress the generation of fine powders by a simple method, and to provide adhesion to a substrate, surface smoothness, scratch resistance, and low friction characteristics. Another object of the present invention is to provide a carbon film forming method for forming a high quality carbon film.

  The above object of the present invention is achieved by the following configurations.

  1. In a carbon film forming method of forming a carbon film on a substrate using plasma discharge under atmospheric pressure or a pressure near atmospheric pressure, a step of introducing a discharge gas into a discharge space and exciting the discharge gas, and the excited discharge gas And a source gas containing carbon in the vicinity of the substrate outside the discharge space to form a secondary excitation gas, and exposing the substrate to the secondary excitation gas to thereby form a carbon film on the substrate. A method for forming a carbon film, comprising: a thin film forming step 1 for forming a film; and a step 2 for exposing the carbon film formed in the thin film forming step 1 to an excitation gas.

  2. The excitation gas used in step 2 is nitrogen gas containing at least one gas selected from 1) nitrogen gas, 2) noble gas, 3) oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and metal-containing gas, Or 4) The carbon film forming method as described in 1 above, which is a rare gas containing at least one kind of gas selected from oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and metal-containing gas.

  3. 3. The carbon film forming method according to 1 or 2, wherein the thickness of the carbon film formed in the thin film forming step 1 is 1 nm or more and 20 nm or less.

  4). 4. The carbon film forming method according to any one of 1 to 3, wherein the carbon-containing source gas is a gas containing hydrocarbon or alcohol.

  5). 5. The carbon film forming method according to any one of 1 to 4, wherein the discharge space is formed by applying a high frequency voltage between opposing electrodes.

  6). 6. The carbon film forming method as described in 5 above, wherein the high-frequency voltage has a frequency of 10 kHz or more and 10 GHz or less.

  7. The discharge gas is 1) nitrogen gas, 2) rare gas, 3) oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and nitrogen gas containing at least one gas selected from metal-containing gas, or 4) oxygen 7. The carbon film forming method according to any one of 1 to 6, wherein the carbon film forming method is a rare gas containing at least one gas selected from gas, carbon dioxide gas, chlorine gas, hydrogen gas, and metal-containing gas. .

  8). 8. The carbon film forming method according to any one of 1 to 7, wherein the base material is a polymer film or a polymer film having a metal-containing thin film as an outermost layer.

  9. 9. The carbon film forming method according to any one of 1 to 8, wherein the carbon-containing source gas contains nitrogen gas or rare gas as a carrier gas.

  10. 10. The carbon film forming method according to any one of 1 to 9, wherein the carbon film has a hydrogen atom content of 30 atomic% or more.

  11. 11. The carbon film formation according to any one of 1 to 10, wherein the carbon-containing source gas is introduced horizontally with respect to the substrate, and is associated with the excited discharge gas outside the discharge space. Method.

  According to the present invention, there is provided a carbon film forming method for forming a high-quality carbon film having a simple method that suppresses generation of fine powder and has adhesion to a substrate, surface smoothness, scratch resistance, and low friction characteristics. Could be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the present inventors have found that in a carbon film forming method for forming a carbon film on a substrate using plasma discharge under atmospheric pressure or a pressure near atmospheric pressure, a discharge gas In the discharge space, exciting the excited discharge gas and a carbon-containing source gas in the vicinity of the substrate outside the discharge space to form a secondary excitation gas, and the secondary A thin film forming step 1 for forming a carbon film on the base material by exposing the base material to the excitation gas; and a step 2 for exposing the carbon film formed in the thin film forming step 1 to the excitation gas. Carbon that forms high-quality carbon films with low adhesion, surface smoothness, and low friction properties with a simple method that suppresses the generation of fine powders by adopting a carbon film formation method that is characterized As soon as it has been found that a film forming method can be realized, the present invention has been achieved. A.

  As described above, in the carbon film forming method of the present invention, after exciting the discharge gas between the counter electrodes, in this discharge space, without introducing the raw material gas containing carbon, the excited discharge gas, A carbon source gas is mixed outside the discharge space to form a secondary excitation gas, and the substrate is exposed to the secondary excitation gas, thereby containing carbon in the region near the substrate (outside the discharge space). Since the source gas is mixed with the excited discharge gas and excited, the secondary excitation gas reaches the substrate surface before vapor phase growth that grows into fine particles in the space region. Can be effectively prevented. However, since the secondary excitation gas including the source gas is formed outside the discharge space only by the above method, the energy that can be applied is slightly insufficient in forming the hard carbon film. This is because the bonding force between carbon atoms and hydrogen atoms in the carbon film is high, and the secondary excitation gas alone cannot break the bond, and as a result, many hydrogen atoms remain in the carbon film. ing. When the hydrogen atom ratio in the carbon film is increased, the hardness of the formed carbon film is lowered and soft, and the resistance to external pressure is reduced. As a result of investigating improvement means for the above problem, the present inventors used a excitation gas for the formed carbon film as a secondary process (step 2) after forming a carbon film containing hydrogen atoms. By performing plasma treatment (also referred to as post-treatment), hydrogen atoms in the carbon film are removed, and a carbon film with high hardness is formed.

  Details of the present invention will be described below.

<< carbon film formation process (process 1) >>
[Atmospheric pressure plasma discharge treatment equipment]
First, an atmospheric pressure plasma discharge treatment apparatus applied to the carbon film forming method of the present invention will be described.

  An atmospheric pressure plasma discharge treatment apparatus applied to the carbon film forming method of the present invention includes a step of exciting a discharge gas introduced into a discharge space under atmospheric pressure or a pressure near atmospheric pressure, the excited discharge gas, A step of mixing carbon-containing source gas in the vicinity of the substrate outside the discharge space to form a secondary excitation gas; and exposing the substrate to the secondary excitation gas to form a carbon film on the substrate. A thin film forming step 1 to be formed, and a step 2 in which the carbon film formed in the thin film forming step 1 is exposed to an excitation gas.

  Generally, methods for forming a functional thin film on a substrate are roughly classified into physical vapor deposition and chemical vapor deposition. Physical vapor deposition is performed on the surface of a substance in the gas phase. This is a method of depositing a thin film of a target substance (for example, a carbon film) by a physical method. Examples of these methods include vapor deposition (resistance heating method, electron beam vapor deposition, molecular beam epitaxy), and ion plating. Such as a sputtering method and a sputtering method. On the other hand, the chemical vapor deposition method is a method in which a raw material gas containing a target thin film component is supplied onto a substrate, and a film is deposited by a chemical reaction on the substrate surface or in the gas phase. For the purpose of activating the plasma, there is a method of generating plasma or the like, and examples thereof include a plasma CVD (chemical vapor deposition method) method and an atmospheric pressure plasma CVD method.

  Among them, the present invention is characterized by applying an atmospheric pressure plasma treatment method (hereinafter also referred to as an atmospheric pressure plasma CVD method).

  Compared with the plasma CVD method under vacuum, the atmospheric pressure plasma processing method, which performs plasma CVD processing near atmospheric pressure, does not require a reduced pressure and is not only highly productive, but also has a high plasma density. The film speed is high, and further, under a high pressure condition of atmospheric pressure as compared with the conditions of a normal CVD method, the gas mean free path is very short, so that a very homogeneous film can be obtained.

  For example, the carbon film mainly composed of carbon according to the present invention excites a gas containing a source gas containing carbon in a discharge space where a high-frequency electric field is generated under atmospheric pressure or a pressure in the vicinity thereof. In this method, a secondary excitation gas is formed by mixing with the discharge gas, the substrate is exposed to the secondary excitation gas, and then the formed carbon film is exposed to the excitation gas to form a hard carbon film.

  The atmospheric pressure or the pressure in the vicinity thereof in the present invention is about 20 kPa to 110 kPa, and 93 kPa to 104 kPa is preferable in order to obtain the good effects described in the present invention.

  The excited gas as used in the present invention means that at least a part of the molecules in the gas move from the existing state to a higher state by obtaining energy. Excited gas molecules, radicalized gas molecules A gas containing ionized gas molecules corresponds to this.

  That is, as a first step, the pressure between the counter electrodes (discharge space) is set to atmospheric pressure or a pressure near it, a discharge gas is introduced between the counter electrodes, a high frequency voltage is applied between the counter electrodes, and the discharge gas is converted into plasma. Then, the discharge gas and the raw material gas that are in the plasma state are mixed outside the discharge space, and the substrate is exposed to this mixed gas (secondary excitation gas) to form a carbon film on the substrate. To do. Next, as a second step, the hard carbon film is formed by exposing the formed carbon film to an excitation gas and removing hydrogen atoms.

  Hereinafter, an atmospheric pressure plasma discharge processing apparatus according to the present invention will be described with reference to the drawings. In addition, although the following description may include assertive expressions for terms and the like, they show preferred examples of the present invention and limit the meaning and technical scope of the terms of the present invention. It is not a thing.

  Conventionally known atmospheric pressure plasma discharge treatment apparatuses are roughly classified into the following two systems.

  One method is a so-called jet-type atmospheric pressure plasma discharge treatment apparatus, in which a high-frequency voltage is applied between counter electrodes, a gas containing a discharge gas is supplied between the counter electrodes, and the discharge gas is converted into plasma. Then, after the plasmad discharge gas and the source gas are associated and mixed, they are sprayed on the substrate outside the discharge space to form a thin layer.

  The other method is a so-called direct-type atmospheric pressure plasma discharge treatment apparatus, in which a mixed gas containing a discharge gas and a raw material gas are mixed, and then the discharge space in a state where a substrate is supported between the counter electrodes. The above mixed gas is introduced, a high frequency voltage is applied between the counter electrodes, and a thin layer is formed on the substrate in the discharge space.

  The atmospheric pressure plasma discharge treatment apparatus according to the present invention is basically a method using the former jet type atmospheric pressure plasma discharge treatment apparatus.

  Before explaining the atmospheric pressure plasma discharge treatment apparatus according to the present invention, a conventional direct type large-sized gas is introduced in which a mixed gas of a source gas and a discharge gas is introduced into the discharge space between the counter electrodes to form an excitation gas in the discharge space. An atmospheric pressure plasma discharge treatment apparatus will be described.

  FIG. 1 is a schematic view showing an example of a direct atmospheric pressure plasma discharge treatment apparatus of a comparative example in which a mixed gas of a source gas and a discharge gas is introduced into a discharge space to form an excitation gas in the discharge space.

  The two-frequency jet type atmospheric pressure plasma discharge processing apparatus shown in FIG. 1 is not shown in FIG. 1 in addition to the plasma discharge processing apparatus and the electric field applying means having two power sources. A device having means.

The atmospheric pressure plasma discharge processing apparatus 210 has a counter electrode composed of a first electrode 211 and a second electrode 212, and the frequency from the first power source 221 is provided between the counter electrodes between the counter electrode and the first electrode 211. A _first high-frequency electric field of ω ₁ , electric field strength V ₁ , and current I ₁ is applied, and a second frequency of ω ₂ , electric field strength V ₂ , and current I ₂ from the second power source 222 is applied to the second electrode 212. A high frequency electric field is applied. The first power source 221 can apply a higher frequency electric field strength (V ₁ > V ₂ ) than the second power source 222, and the first frequency ω ₁ of the first power source 221 is higher than the second frequency ω ₂ of the second power source 222. A low frequency can be applied.

  A first filter 223 is installed between the first electrode 211 and the first power source 221, which facilitates the passage of current from the first power source 221 to the first electrode 211, and the current from the second power source 222. Is designed so that the current from the second power source 222 to the first power source 221 is less likely to pass through.

  In addition, a second filter 224 is installed between the second electrode 212 and the second power source 222 to facilitate passage of current from the second power source 222 to the second electrode, and from the first power source 221. It is designed to ground the current and make it difficult to pass the current from the first power source 221 to the second power source 222.

  A mixed gas MG of a discharge gas and a raw material gas containing a raw material compound for forming a thin film is introduced from the gas supply means into the space (discharge space) 213 between the counter electrodes of the first electrode 211 and the second electrode 212, A discharge is generated by applying a high-frequency electric field from the first electrode 211 and the second electrode 212, and the excited mixed gas MG 'in which the mixed gas MG is changed to a plasma state is jetted out to the lower side of the counter electrode (the lower side of the paper). Then, the processing space formed by the lower surface of the counter electrode and the base material F is filled with a plasma gas MG °, and a thin film is formed near the processing position 214 on the base material F conveyed from the previous process. It is. During the formation of the thin film, the medium heats or cools the electrode through the pipe from the electrode temperature adjusting means. Depending on the temperature of the substrate during the plasma discharge treatment, the physical properties and composition of the resulting thin film may change, and the temperature is controlled using an insulating material such as distilled water or oil as a temperature control medium. . FIG. 1 shows a measuring instrument used for measuring the high-frequency electric field strength (applied electric field strength) and the discharge starting electric field strength. 225 and 226 are high-frequency voltage probes, and 227 and 228 are oscilloscopes.

  However, a mixed gas MG obtained by mixing a discharge gas and a raw material gas containing a raw material compound containing carbon for forming a carbon film is directly applied in the discharge space between the counter electrodes (in the discharge space) as shown in FIG. Therefore, a certain amount of time is required until the target base material is reached after the mixed gas MG containing the source gas is excited. As a result, in the mixed gas MG ′ excited in the discharge space, fine particles (dust) are generated due to vapor phase growth, and the dust adheres to the surface of the counter electrode, causing discharge failure, or By reaching and depositing on the surface of the substrate, it becomes a factor inducing the occurrence of pinholes and the like.

  In the present invention, as a result of investigations to solve the above problems, a step of introducing a discharge gas into a discharge space and exciting it under atmospheric pressure or a pressure near atmospheric pressure, the excited discharge gas, and carbon A step of mixing the raw material gas contained in the vicinity of the base material outside the discharge space to form a secondary excitation gas, and exposing the base material to the secondary excitation gas to form a carbon film on the base material An atmospheric pressure plasma discharge treatment apparatus comprising a carbon film forming step 1 for forming a carbon film on a substrate and a step 2 for subsequently removing the hydrogen atoms by exposing the formed carbon film to an excitation gas is used. It is characterized by that.

  FIG. 2 is a schematic view showing an example of a jet type atmospheric pressure plasma discharge treatment apparatus according to the present invention.

  In FIG. 2, the atmospheric pressure plasma discharge processing apparatus 21 has two pairs of electrodes 41 a and 41 b connected to a power source 31 arranged in parallel. At least one of the electrodes 41a and 41b is covered with a dielectric 42, and a high frequency voltage is applied by a power source 31 to a discharge space 43 formed between the electrodes.

  The inside of the electrodes 41a and 41b has a hollow structure 44, and during the discharge, heat generated by the discharge can be obtained by water, oil, etc., and heat exchange can be performed so as to maintain a stable temperature.

  Further, by each gas supply means (not shown), the discharge gas 22 necessary for discharge is supplied to the discharge space 43 through the flow path 24, and a high frequency voltage is applied to the discharge space 43 to generate plasma discharge. As a result, the gas 22 containing the discharge gas is turned into plasma and becomes the excited discharge gas G ′. The plasma-induced excitation discharge gas G ′ is ejected into the mixing space 45.

  On the other hand, a raw material gas 23 containing a gas containing carbon necessary for forming a carbon film supplied by a gas supply means (not shown) passes through the flow path 25 and is also transported to the mixing space 45 to be converted into the plasma. The secondary excitation gas merged and mixed with the excitation discharge gas G ′ is sprayed onto the transparent substrate placed on the moving stage 47 or the substrate 46 including the transparent substrate on the outermost surface.

  The secondary excitation gas in which the excitation discharge gas G ′ converted into plasma and the raw material gas for forming the carbon film is mixed is activated by the energy of the plasma to cause a chemical reaction, and a carbon film is formed on the substrate 46. Is done.

  This jet type atmospheric pressure plasma discharge apparatus has a structure in which a source gas containing a gas necessary for forming a carbon film is sandwiched or surrounded by an activated discharge gas.

  The moving stage 47 on which the base material is mounted has a structure capable of reciprocating scanning or continuous scanning, and can perform heat exchange similar to the above electrode so that the temperature of the base material can be maintained if necessary. It has become.

  In addition, a waste gas exhaust passage 48 for exhausting the gas blown onto the substrate 46 can be attached as necessary. Thereby, unnecessary by-products formed in the space can be quickly removed from the discharge space 45 or the substrate 46.

  This plasma jet type atmospheric pressure plasma discharge treatment apparatus has a structure in which a discharge gas is activated by being converted into plasma and then merged with a raw material gas containing a gas necessary for forming a carbon film. As a result, it is possible to prevent deposits from being deposited on the electrode surface. Furthermore, by attaching a dirt prevention film or the like to the electrode surface, the gas necessary for forming the discharge gas and the carbon film can be reduced before discharge. It can also be set as the structure to mix.

  FIG. 3 is a schematic view showing another example of a plasma jet type atmospheric pressure plasma discharge processing apparatus according to the present invention.

  In FIG. 2, the flow path 24 for supplying the gas 22 containing the discharge gas and the flow path 25 for supplying the source gas 23 containing the gas necessary for forming the carbon film are provided in parallel. As shown in FIG. 3, a method may be used in which the flow path 24 for supplying the gas 22 containing the discharge gas is formed obliquely and the mixing efficiency with the raw material gas 23 supplied from the flow path 25 is increased.

  In the apparatus shown in FIGS. 2 and 3 described above, the high frequency power supply is performed in one frequency band. For example, the method described in Japanese Patent Application Laid-Open No. 2003-96569 or the following FIG. Similarly, it is also possible to implement by a method in which power sources of different frequencies are installed on each electrode.

  FIG. 4 is a schematic view showing an example of a two-frequency jet type atmospheric pressure plasma discharge treatment apparatus useful for the present invention.

  The jet type atmospheric pressure plasma discharge processing apparatus has a gas supply means and an electrode temperature adjusting means (not shown in FIG. 4) in addition to the plasma discharge processing apparatus and the electric field applying means having two power sources. Device.

  In FIG. 4, the basic configuration is the same as in FIG. 2, but the second high frequency filter 101b and the second high frequency power supply 31b are connected to the electrode 41b, and the electrode 41a is connected to the first high frequency filter 101a and the first high frequency filter 101a. One high frequency power supply 31a is connected, and two different high frequency voltages are applied to each.

The atmospheric pressure plasma discharge processing apparatus 21 has a counter electrode composed of a first electrode 41a and a second electrode 41b, and the frequency from the first power source 31a is transmitted from the first electrode 41a to the counter electrode. A _first high-frequency electric field of ω ₁ , electric field strength V ₁ , and current I ₁ is applied, and a second ω ₂ , electric field strength V ₂ , and _second current I ₂ from the second power source 31b are applied from the second electrode 41b. A high frequency electric field is applied. The first power source 31a can apply a higher frequency electric field strength (V ₁ > V ₂ ) than the second power source 31b, and the first frequency ω ₁ of the first power source 31a is higher than the second frequency ω ₂ of the second power source 31b. A low frequency can be applied.

  A first filter 101a is installed between the first electrode 41a and the first power supply 31a, which facilitates the passage of current from the first power supply 31a to the first electrode 41a, and the current from the second power supply 31b. Is designed so that the current from the second power supply 31b to the first power supply 41a does not easily pass.

  In addition, a second filter 101b is installed between the second electrode 41b and the second power source 31b to facilitate passage of current from the second power source 31b to the second electrode 41b, and from the first power source 31a. Is designed so that the current from the first power supply 31a to the second power supply 31b is difficult to pass.

  The discharge gas 22 is introduced from the gas supply means between the opposing electrodes (discharge space) 43 between the first electrode 41a and the second electrode 42b, and a high frequency electric field is applied from the first electrode 41a and the second electrode 41b to discharge. The discharge gas 22 is blown out in a jet shape to the lower side of the counter electrode (the lower side of the paper) while the discharge gas 22 is in a plasma state, and the processing space formed by the lower surface of the counter electrode and the base material F is formed with a secondary excitation gas in a plasma state. A carbon film is formed on the substrate F that is filled and conveyed from the previous process. During the carbon film formation, the medium heats or cools the electrode through the pipe from the electrode temperature adjusting means. Depending on the temperature of the substrate during the plasma discharge treatment, the physical properties and composition of the resulting carbon film may change, and it is desirable to appropriately control this. As the temperature control medium, an insulating material such as distilled water or oil is preferably used. During the plasma discharge treatment, it is desirable to uniformly adjust the temperature inside the electrode so that the temperature unevenness of the base material in the width direction or the longitudinal direction does not occur as much as possible.

  Moreover, in the atmospheric pressure plasma discharge treatment apparatus according to the present invention, it is preferable that the raw material gas containing carbon is introduced horizontally with respect to the base material and is associated with the excited discharge gas outside the discharge space.

  FIG. 5 is a schematic view showing an example of an atmospheric pressure plasma discharge treatment apparatus that horizontally supplies a source gas applicable to the present invention to a substrate.

  The atmospheric pressure plasma processing apparatus shown in FIG. 5 supplies only the discharge gas to the discharge space formed between the counter electrodes as an excitation gas, while supplying the source gas containing the carbon film forming material in parallel with the base material. The discharge gas excited outside the discharge space and the source gas supplied horizontally are combined and mixed to form a secondary excitation gas, and carbon is obtained by instantly exposing the substrate to the secondary excitation gas. This is a method of forming a film.

  The basic configuration of the atmospheric pressure plasma discharge processing apparatus shown in FIG. 5 is similar to the configuration shown in FIG. 1, but the first electrode 103a connected to the first power source 121 and the second power source are opposed to each other. A second electrode 103 b connected to 122 is arranged. At least one of the electrodes is covered with a dielectric, and a plasma discharge is generated by applying a high frequency voltage from the power supplies 121 and 122 to the discharge space 106 formed between the electrodes.

  By supplying the discharge gas G from the discharge gas supply means 105 to the space between the counter electrodes (discharge space) 106, the discharge gas G is excited to become the excited discharge gas G ', and the mixed region with the source gas outside the discharge space 109.

  On the other hand, the raw material gas M containing the raw material compound for forming the carbon film is supplied from the raw material gas supply means 107 to the raw material gas supply path 108 and sent to the mixing region 109 in a state parallel to the base material F. The gas G ′ and the outside of the discharge space are mixed to form the secondary excitation gas 110. The carbon film 111 is formed on the base material F by exposing the base material F to the secondary excitation gas 110. The gas 112 used for forming the carbon film is discharged out of the system through the exhaust gas passage 113.

A first high-frequency electric field having a frequency ω ₁ , an electric field strength V ₁ , and a current I ₁ from the first power source 121 is applied to the first electrode 103a provided between the counter electrodes, and a second high-frequency electric field is applied to the second electrode 103b. A second high frequency electric field of frequency ω ₂ , electric field strength V ₂ , and current I ₂ from the power source 122 is applied. The first power supply 121 can apply a higher frequency electric field strength (V ₁ > V ₂ ) than the second power supply 122, and the first frequency ω ₁ of the first power supply 121 is higher than the second frequency ω ₂ of the second power supply 122. A low frequency can be applied.

  A first filter 123 is installed between the first electrode 103a and the first power supply 121, and it is easy to pass current from the first power supply 121 to the first electrode 103a. Is designed so that the current from the second power supply 122 to the first power supply 121 does not easily pass.

  In addition, a second filter 124 is installed between the second electrode 103b and the second power source 122 to facilitate passage of current from the second power source 122 to the second electrode 103b. Is designed so that the current from the first power supply 121 to the second power supply 122 is difficult to pass. FIG. 5 shows a measuring instrument used for measuring the high-frequency electric field strength (applied electric field strength) and the discharge starting electric field strength. 125 and 126 are high-frequency voltage probes, and 127 and 128 are oscilloscopes.

  Examples of the high-frequency power source that can be used in the atmospheric pressure plasma discharge processing apparatus described in each figure include a high-frequency power source (3 kHz) manufactured by Shinko Electric, a high-frequency power source (5 kHz) manufactured by Shinko Electric, a high-frequency power source (15 kHz) manufactured by Shinko Electric, Shinko Electric High Frequency Power Supply (50 kHz), Hayden Laboratory High Frequency Power Supply (continuous mode use, 100 kHz), Pearl Industrial High Frequency Power Supply (200 kHz), Pearl Industrial High Frequency Power Supply (800 kHz), Pearl Industrial High Frequency Power Supply (2 MHz), A high frequency power source (13.56 MHz) manufactured by JEOL Ltd., a high frequency power source manufactured by Pearl Industries (27 MHz), a high frequency power source manufactured by Pearl Industries (150 MHz), or the like can be used. Alternatively, a power source that oscillates at 433 MHz, 800 MHz, 1.3 GHz, 1.5 GHz, 1.9 GHz, 2.45 GHz, 5.2 GHz, or 10 GHz may be used. Among them, as a high frequency power source applied in the present invention, a high frequency power source having a frequency of 10 kHz or more and 10 GHz or less is preferably used, and a high frequency power source having a frequency of 1 GHz or more and 10 GHz or less is further preferably used.

In the present invention, for example, in the case of the two-frequency system, the power supplied between the electrodes facing each other from the first and second power sources supplies power (output density) of 1 W / cm ² or more to the fixed electrode 21 and discharges. A gas is excited to generate plasma, and an excited discharge gas is obtained. The upper limit value of the power supplied to the fixed electrode is preferably 50 W / cm ² . The lower limit is preferably 1.2 W / cm ² . The discharge area (cm ² ) refers to an area in a range where discharge occurs in the electrode.

  Here, the waveform of the high-frequency electric field is not particularly limited. There are a continuous sine wave continuous oscillation mode called continuous mode and an intermittent oscillation mode called ON / OFF intermittently called pulse mode. Either of them can be used, but the supplied high frequency is the continuous sine wave This is preferable because a denser and better quality film can be obtained.

  It is preferable to use an electrode that can maintain a uniform and stable discharge state by applying a strong electric field as described above to the electrode, and the fixed electrode has at least one electrode surface to withstand discharge by a strong electric field. Is coated with the following dielectric.

  FIG. 6 is a perspective view showing an example of the fixed electrode.

  In FIG. 6A, a rectangular columnar fixed electrode 221 is coated with a ceramic coated dielectric 210d that is sealed with an inorganic material after thermal spraying of ceramic on a conductive base material 210c such as metal. It consists of a combination. Further, as shown in FIG. 7B, the prismatic fixed electrode 221 'is configured by combining a conductive base material 210A such as metal with a lining dielectric 210B provided with an inorganic material by lining. May be.

  When the carbon film is formed on the substrate using the various atmospheric pressure plasma discharge treatment apparatuses applicable to the present invention described above, the film thickness of the carbon film is not particularly limited, but is 1 nm or more and 20 nm. The following is preferable.

[Various gases and base materials used for carbon film formation]
Next, each material used in the carbon film forming method of the present invention using an atmospheric pressure plasma discharge treatment apparatus will be described.

(Raw material gas)
In the method for forming a carbon film of the present invention, a gas or liquid organic compound gas, particularly a hydrocarbon gas, is used as a raw material gas for forming the carbon film at room temperature. The phase state of these raw materials does not necessarily need to be a gas phase at normal temperature and normal pressure, and can be a liquid phase or a solid phase as long as it can be vaporized through heating, decompression, etc. through melting, evaporation, sublimation, etc. But it can be used. As for the hydrocarbon gas as the raw material gas, for example, paraffinic hydrocarbons such as CH ₄ , C ₂ H ₆ , C ₃ H ₈ and C ₄ H ₁₀ , and acetylene carbonization such as C ₂ H ₂ and C ₂ H ₄ are used. Gases containing at least all hydrocarbons such as hydrogen, olefinic hydrocarbons, diolefinic hydrocarbons, and aromatic hydrocarbons can be used. Further, other than hydrocarbons, for example, alcohols, ketones, ethers, esters, CO, CO _{2 and the} like can be used as long as they are compounds containing at least a carbon element. In the present invention, hydrocarbons or alcohols are particularly preferable. It is preferable to contain. The source gas preferably contains nitrogen gas or a rare gas as a carrier gas.

  In the present invention, a hard carbon film such as an amorphous carbon film, a hydrogenated amorphous carbon film, a tetrahedral amorphous carbon film, a nitrogen-containing amorphous carbon film, or a metal-containing amorphous carbon film is formed using the source gas. Further, in the carbon film according to the present invention, the hydrogen atom content is preferably 30 atomic% or more.

(Discharge gas)
The discharge gas refers to a gas that is plasma-excited under the conditions applied between the counter electrodes. Examples of the discharge gas that can be preferably applied in the present invention include 1) nitrogen gas, 2) argon, helium, neon, krypton, xenon, and the like. 3) Oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and nitrogen gas containing at least one gas selected from metal-containing gas, or 4) oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas And a rare gas containing at least one gas selected from metal-containing gases. Of these, nitrogen and argon are preferably used.

(Base material)
In the carbon film forming method of the present invention, the substrate for forming the carbon film according to the present invention is not particularly limited, but a polymer film or a polymer film having a metal-containing thin film as the outermost layer is preferable.

  Examples of the polymer film applied to the present invention include polymethyl methacrylate (PMMA), acrylonitrile-butadiene-styrene resin (ABS), ethylene-vinyl acetate resin (EVAC), ethylene-vinyl alcohol resin (EVOH), and polyamide. (PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polymethylpentene (PMP), polypropylene ( PP), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), styrene-acrylonitrile resin (SAN), triacetyl cellulose (TAC), cellulose triacete Polymer films such as cellulose esters such as cellulose diacetate, cellulose acetate propionate or cellulose acetate butyrate, polyimide, polyetheretherketone, polyvinylidene fluoride, ethylenetetrafluoroethylene copolymer, polyamide and polyphenylene So-called engineering plastic materials such as sulfide can be used. These polymer films can be added with a conductive agent or the like as required. Carbon black can be used as the conductive agent. Carbon black can be used without particular limitation, and neutral carbon black may be used.

  Moreover, the form which has a metal containing thin film on the polymer film mentioned above may be sufficient. Examples of these metal-containing thin films include thin films composed of metal oxides, metal nitrides, or metal oxynitrides, such as thin films formed of organic metal compounds, halogen metal compounds, metal hydrogen compounds, and the like. Examples thereof include silicon oxide, silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, aluminum oxynitride, magnesium oxide, zinc oxide, indium oxide, and tin oxide.

<< Post-treatment process of carbon film with excitation gas (process 2) >>
In the carbon film forming method of the present invention, the carbon film formed in the thin film forming step 1 is formed after forming the carbon film on the substrate according to the thin film forming step 1 using the atmospheric pressure plasma discharge treatment apparatus described above. The treatment is performed in the step 2 of exposing to an excitation gas. By treating the carbon film using this high energy excitation gas, hydrogen atoms in the carbon film are removed to form a carbon film with high hardness.

  As the atmospheric pressure plasma discharge treatment apparatus applicable in the process 2 of the present invention, the apparatus shown in FIGS. 1 to 4 described in the thin film formation process 1 can be used. When these atmospheric pressure plasma discharge treatment apparatuses are used in step 2, the excitation gas is introduced into only the discharge space formed between the counter electrodes and a high frequency voltage is applied to bring the excitation gas into a plasma state. By exposing the carbon film to the converted excitation gas, a hard carbon film can be obtained by dehydrogenation treatment.

  The excited gas species that can be used in the process includes at least one gas selected from 1) nitrogen gas, 2) noble gas, 3) oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas, and metal-containing gas. Nitrogen gas, 4) A rare gas containing at least one gas selected from oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and metal-containing gas is preferable.

  The step 2 according to the present invention may be performed continuously in an online manner following the thin film forming step 1 which is a carbon film forming step, or may be conducted in an offline manner in a state separated from the step 1. However, in consideration of production efficiency, it is preferable that the atmospheric pressure plasma discharge treatment apparatus for the thin film forming step 1 and the atmospheric pressure plasma discharge treatment apparatus for the step 2 are arranged in series and the treatment is performed on-line.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
《Preparation of carbon film formation sample》
[Preparation of Sample 1]
(Thin film forming step 1)
As a base material, on a polyethylene naphthalate film having a thickness of 100 μm (a film made by Teijin DuPont Co., Ltd., hereinafter abbreviated as PEN), using a single frequency plasma jet type atmospheric pressure plasma processing apparatus shown in FIG. A sample 1 was obtained by forming a carbon film having a thickness of 200 nm under the following gas conditions and discharge conditions.

<Power supply conditions>
Power supply: High frequency side 27.12 MHz 6 W / cm ²
<Electrode conditions>
The square electrodes of the first electrode 41a and the second electrode 41b were manufactured by performing ceramic spraying as a dielectric on a 30 mm square hollow titanium pipe.

Dielectric thickness: 1mm
Electrode width: 300mm
Applied electrode temperature: 90 ° C
Slit gap between electrodes: 1.0mm
<Gas conditions>
Discharge gas: Ar, 100 slm
Source gas: C ₂ H ₂ , 200 sccm
Using the plasma jet type atmospheric pressure plasma processing apparatus 21 shown in FIG. 2, the discharge gas 22 (Ar gas) is supplied from the discharge gas supply means to the space between the counter electrodes (discharge space) 43, and the power source 31 is interposed between the counter electrodes. A higher frequency voltage was applied to form an excited discharge gas G ′. The source gas (C ₂ H ₂ gas) is supplied from the source gas supply means to the source gas supply path 25 and mixed with the excitation discharge gas G ′ outside the discharge space 45 to obtain a secondary excitation gas. As a result, a carbon film 46 was formed.

(Process 2)
The sample in which the carbon film is formed on the base material in the thin film forming step 1 is subjected to the treatment with the excitation gas under the following conditions using the plasma jet type atmospheric pressure plasma processing apparatus 21 shown in FIG. Sample 1 was prepared.

<Power supply conditions>
First power supply: high frequency side 27.12 MHz 6 W / cm ²
Second power source: low frequency side 100 kHz 5 W / cm ²
<Electrode conditions>
The square electrodes of the first electrode 211 and the second electrode 212 were manufactured by subjecting a 30 mm square hollow titanium pipe to ceramic spraying as a dielectric.

Dielectric thickness: 1mm
Electrode width: 300mm
Applied electrode temperature: 90 ° C
<Gas conditions>
Discharge gas: N ₂ , 100 slm
[Preparation of Sample 2]
Sample 2 was produced in the same manner as in the production of Sample 1 except that the excitation gas in Step 2 was changed to Ar gas.

[Preparation of Sample 3]
Sample 3 was prepared in the same manner as Sample 1 except that 10 sccm of hydrogen gas was added as a reaction gas to the discharge gas in the thin film forming step 1.

[Preparation of Sample 4]
Sample 4 was prepared in the same manner as Sample 1 except that CH ₄ was used in place of C ₂ H ₂ as the raw material gas for thin film formation step 1.

[Preparation of Sample 5]
In the production of Sample 1, Sample 5 was produced in the same manner except that the apparatus shown in FIG. 3 was used instead of the apparatus shown in FIG. 2 as the plasma jet type atmospheric pressure plasma processing apparatus in thin film forming step 1. did.

[Preparation of Sample 6]
In the preparation of the sample 1, the apparatus shown in FIG. 4 is used instead of the apparatus shown in FIG. 2 as the plasma jet type atmospheric pressure plasma processing apparatus in the thin film forming step 1, and the same discharge conditions are used. Thus, Sample 6 was produced.

(Thin film forming step 1)
As a base material, on the polyethylene naphthalate film (film made by Teijin DuPont) with a thickness of 100 μm, the following gas conditions and discharge conditions were obtained using the two-frequency plasma jet type atmospheric pressure plasma processing apparatus shown in FIG. Thus, a carbon film having a thickness of 200 nm was formed.

<Power supply conditions>
First power supply: high frequency side 27.12 MHz 6 W / cm ²
Second power source: low frequency side 100 kHz 5 W / cm ²
<Electrode conditions>
The square electrodes of the first electrode 41a and the second electrode 41b were manufactured by performing ceramic spraying as a dielectric on a 30 mm square hollow titanium pipe.

Dielectric thickness: 1mm
Electrode width: 300mm
Applied electrode temperature: 90 ° C
<Gas conditions>
Discharge gas: N ₂ , 100 slm
Source gas: C ₂ H ₂ , 200 sccm
Using the plasma jet type atmospheric pressure plasma processing apparatus 2 shown in FIG. 4, the discharge gas 22 (N ₂ gas) is supplied from the discharge gas supply means to the space between the counter electrodes (discharge space) 43, and the high frequency is generated between the counter electrodes. A voltage was applied to obtain an excited discharge gas G ′. Source gas (C ₂ H ₂ gas) 23 is supplied from source gas supply means to source gas supply path 25 and mixed with excitation discharge gas G ′ outside discharge space 45 to form secondary excitation gas G ′. The carbon film 46 was formed by exposing the base material 47 to the secondary excitation gas G ′.

(Process 2)
In the same manner as in Step 2 described in Sample 1, surface treatment with excitation gas was performed to obtain Sample 6.

[Preparation of Sample 7]
In the production of the sample 6, as a plasma jet type atmospheric pressure plasma processing apparatus in the thin film forming step 1, a source gas shown in FIG. 5 is supplied horizontally to the electrode instead of the apparatus shown in FIG. Sample 7 was prepared in the same manner except that the plasma jet type atmospheric pressure plasma processing apparatus was used.

[Preparation of Sample 8]
Sample 5 was prepared in the same manner as Sample 1 except that 10 sccm of oxygen gas was further added as a reaction gas to the discharge gas in the thin film forming step 1.

[Preparation of Sample 9]
A gas mixture prepared by mixing the discharge gas (Ar) and the source gas (C ₂ H ₂ ) using the two-frequency plasma jet atmospheric pressure plasma processing apparatus shown in FIG. MG is supplied between the opposing electrodes (discharge space) 213 from the mixed gas supply means, and a high frequency voltage is applied between the power sources 221 and 222 between the opposing electrodes to obtain a mixed excitation mixed gas MG '. This excitation mixed gas MG' Was exposed to a substrate to form a carbon film, and a sample 9 was produced in the same manner.

[Production of Samples 10 to 18]
Samples 10 to 18 were prepared in the same manner as in the preparation of Samples 1 to 9, except that the treatment with the excitation gas in Step 2 was not performed.

<< Evaluation of each sample >>
The following evaluations were performed on each sample having the carbon film prepared above.

[Evaluation of sliding property: measurement of friction coefficient]
The dynamic friction coefficient of the carbon film surface of each sample was measured according to the method described in JIS-K-7125-ISO8295. A stainless steel specimen weighing 300 g is placed on the carbon film surface of each specimen, the specimen is pulled horizontally under the conditions of a specimen moving speed of 100 mm / min and a contact area of 80 mm × 200 mm, and the average load (F ) And the dynamic friction coefficient (μ) was determined from the following formula.

Coefficient of dynamic friction = F (N) / weight of weight (N)
If the dynamic friction coefficient measured by the above method was less than 0.3, it was judged as ◯, 0.3 or more, less than 0.5, Δ, and 0.5 or more as x.

[Evaluation of surface smoothness: measurement of surface roughness Ra]
The surface roughness Ra (nm) of the carbon film surface of each sample was measured according to the following method.

  As an atomic force microscope (AFM), the SPI3800N probe station and SPA400 multifunctional unit manufactured by Seiko Instruments Inc./SII Nanotechnology Co., Ltd. were used as measuring devices. DF20 was used. In the DFM mode (Dynamic Force Mode), a 10 μm square measurement area was measured, and the average roughness Ra (nm) was calculated from the obtained three-dimensional data.

[Evaluation of scratch resistance]
Each carbon film surface produced above was subjected to 10 rubbing treatments using a steel wool (Bonster # 0000) with a friction tester HEIDON-14DR under the conditions of load: 40 kPa and moving speed: 10 mm / min. A range of 1 cm × 1 cm was observed with a magnifying glass, and scratch resistance was evaluated according to the following criteria.

A: No generation of scratches is observed. O: Generation of scratches is 1 or more and 5 or less. Δ: Generation of scratches is 6 or more and 15 or less. X: Generation of scratches is 16 or more. It is 25 or less. XX: Generation of scratches is 25 or more [Evaluation of adhesion]
About each said sample, the cross cut test based on JISK5400 was done. On the surface of the carbon film of each sample, a single-edged razor blade was cut at 90 degrees with respect to the surface, 22 in length and width at intervals of 1.0 mm, to produce 400 1.0 mm square grids. A commercially available cellophane tape is affixed to this, and one end of the tape is peeled off vertically by hand, and the ratio of the peeled area of the carbon film to the affixed tape area from the score line is measured. Was evaluated.

◎: No peeling of the grids occurred ○: The area ratio of the peeled grids was less than 1% △: The area ratio of the peeled grids was 1% or more and less than 5% ×: The area of the peeled grids The ratio is 5% or more and less than 10% XX: Table 1 shows the results obtained when the peeled grid area ratio is 10% or more.

  As is apparent from the results shown in Table 1, the sample of the present invention in which the carbon film was formed in accordance with the method defined in the present invention was superior in surface smoothness to the comparative example in that the formed carbon film had a low friction coefficient. It can be seen that the film has sufficient scratch resistance and has good adhesion to the substrate.

Example 2
In the production of Samples 1, ₂ , 4 to 9, 10, 11, 13 to 18 described in Example 1, the carbon film was formed in the same manner except that ethyl alcohol was used instead of C ₂ H ₂ as the source gas. As a result of evaluating the smoothness, surface smoothness, scratch resistance and adhesion in the same manner as in Example 1, the sample formed according to the method of the present invention obtains the same results as in Table 1. I was able to.

Example 3
In the preparation of Samples 1 to 18 described in Example 1 above, a carbon film was formed in the same manner except that the substrate was replaced with PEN and a substrate having a silicon oxide film on PEN was used. As a result of evaluating the smoothness, surface smoothness, scratch resistance and adhesion in the same manner as in No. 1, the sample formed according to the method of the present invention was able to obtain the same results as in Table 1.

Example 4
In the preparation of Samples 1 to 8 described in Example 1, the carbon film was formed in the same manner except that the carbon film was formed by containing 5% by volume of nitrogen gas and argon gas as carrier gases in the source gas. As a result of evaluating the smoothness, surface smoothness, scratch resistance and adhesion in the same manner as in Example 1, better results than those shown in Table 1 could be obtained.

It is the schematic which shows an example of the direct-type atmospheric pressure plasma discharge processing apparatus of the comparative example which introduces mixed gas of source gas and discharge gas in discharge space, and forms excitation gas in discharge space. It is the schematic which shows an example of the jet type atmospheric pressure plasma discharge processing apparatus which concerns on this invention. It is the schematic which shows another example of the plasma jet type atmospheric pressure plasma discharge processing apparatus which concerns on this invention. It is the schematic which showed an example of the 2 frequency jet type atmospheric pressure plasma discharge processing apparatus useful for this invention. It is the schematic which shows an example of the atmospheric pressure plasma discharge processing apparatus which supplies the raw material gas applicable to this invention horizontally to a base material. It is a perspective view which shows an example of a fixed electrode.

Explanation of symbols

21 Atmospheric pressure plasma discharge treatment device 22, G discharge gas 23, M source gas 24, 25 channel 31 power source 31a, 121 first power source 31b, 122 second power source 41a, 103a electrode (first electrode)
41b, 103b electrode (second electrode)
42 Dielectric 43, 106 Discharge space 45 Mixing space 46 Base material 47 Moving stage 48 Waste gas exhaust passage 101a First filter 101b Second filter 105 Discharge gas supply means 107 Raw material gas supply means 109 Mixing area 110 Secondary excitation gas 221 Fixed electrode G Discharge gas G 'Excited discharge gas

Claims (11)

In a carbon film forming method of forming a carbon film on a substrate using plasma discharge under atmospheric pressure or a pressure near atmospheric pressure, a step of introducing a discharge gas into a discharge space and exciting the discharge gas, and the excited discharge gas And a source gas containing carbon in the vicinity of the substrate outside the discharge space to form a secondary excitation gas, and exposing the substrate to the secondary excitation gas to thereby form a carbon film on the substrate. A method for forming a carbon film, comprising: a thin film forming step 1 for forming a film; and a step 2 for exposing the carbon film formed in the thin film forming step 1 to an excitation gas. The excitation gas used in the step 2 is nitrogen gas containing at least one gas selected from 1) nitrogen gas, 2) noble gas, 3) oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and metal-containing gas, Or 4) The carbon film forming method according to claim 1, wherein the carbon film forming method is a rare gas containing at least one gas selected from oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas, and metal-containing gas. The carbon film forming method according to claim 1 or 2, wherein a thickness of the carbon film formed in the thin film forming step 1 is 1 nm or more and 20 nm or less. The carbon film forming method according to claim 1, wherein the source gas containing carbon is a gas containing hydrocarbon or alcohol. 5. The carbon film forming method according to claim 1, wherein the discharge space is formed by applying a high-frequency voltage between electrodes facing each other. 6. The carbon film forming method according to claim 5, wherein the high-frequency voltage has a frequency of 10 kHz or more and 10 GHz or less. The discharge gas is 1) nitrogen gas, 2) rare gas, 3) oxygen gas, carbon dioxide gas, chlorine gas, hydrogen gas and nitrogen gas containing at least one gas selected from metal-containing gas, or 4) oxygen The carbon film formation according to any one of claims 1 to 6, wherein the carbon film is a rare gas containing at least one gas selected from gas, carbon dioxide gas, chlorine gas, hydrogen gas, and metal-containing gas. Method. The carbon film forming method according to claim 1, wherein the base material is a polymer film or a polymer film having a metal-containing thin film as an outermost layer. The carbon film forming method according to claim 1, wherein the carbon-containing source gas contains nitrogen gas or a rare gas as a carrier gas. The carbon film formation method according to any one of claims 1 to 9, wherein the carbon film has a hydrogen atom content of 30 atomic% or more. 11. The carbon film according to claim 1, wherein the carbon-containing source gas is introduced horizontally with respect to the base material and associated with the excited discharge gas outside the discharge space. Forming method.

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