JP2011162815A - Method for manufacturing fluorine-containing carbon material - Google Patents

Abstract

A method for producing a higher-performance fluorine-containing carbon material (CF material) and / or a CF material production method with higher productivity are provided.
The following steps: (A) In a predetermined atmospheric gas, a source gas containing F and C is deposited on a base material 60 while colliding gas particles accelerated toward the base material 60. A step of forming a deposit; and (B) a step of subjecting a surface of a material to be processed containing F and C to collision with accelerated gas particles toward the surface in a predetermined atmospheric gas. A CF material manufacturing method including at least one is provided. The predetermined atmospheric gas is an atmospheric gas prepared by adding H ₂ O and / or an atmospheric gas containing H ₂ O as a main component.
[Selection] Figure 1

Description

  The present invention relates to a method for producing a material containing fluorine and carbon.

Diamond-like carbon (hereinafter sometimes referred to as “DLC”) is an amorphous material having a basic structure of a carbon network containing SP ³ bonds similar to diamond and SP ² bonds similar to graphite. A generic term for carbonaceous materials. This DLC has various excellent properties such as mechanical properties such as high hardness, wear resistance, low friction coefficient, surface smoothness, chemical properties such as chemical resistance and corrosion resistance, and electrical properties such as insulation. It has been attracting attention as a high-functional material that can exhibit excellent properties.

  As a conventional method for forming DLC on a substrate surface in a film form (ie, a method for producing a DLC film), there is a plasma CVD method in which a raw material gas supplied into a reaction vessel (chamber) is converted into plasma and deposited on the substrate surface Can be mentioned. Patent documents 1 and 2 are illustrated as prior art documents concerning this kind of technology. Patent Document 3 describes a technique for manufacturing a thin film such as a DLC film by a plasma CVD method in which a liquid carbon compound is supplied to a reaction tube by ultrasonic spraying. On the other hand, as another method for manufacturing the DLC film, there is exemplified a laser ablation method in which a raw material (target) is irradiated with laser light to evaporate the raw material and deposit the evaporated material on the substrate surface. Patent document 4 is mentioned as a prior art document regarding this kind of technique.

  In addition, in the patent document 5, the present inventor efficiently forms a DLC film or other carbonaceous film from a solid organic material by forming plasma using discharge energy from a solid organic material having good handleability. Proposes well-manufactured methods and apparatus.

JP 2004-169183 A JP-A-8-217596 JP-A-8-1000026 JP-A-9-118976 International Publication No. 2008/069312 Pamphlet

  A typical DLC consists essentially of carbon (C) and hydrogen (H). On the other hand, by including fluorine (F) in DLC or other carbon-containing materials (for example, organic materials such as various synthetic resins), characteristics such as water repellency and a low friction coefficient can be imparted or improved. Are known. For example, in the method described in Patent Document 5, a carbonaceous film containing fluorine (that is, a fluorine-containing carbon material, typically a fluorine-containing DLC film) is produced by using a solid organic material containing fluorine as a raw material. obtain.

  The present invention relates to such a fluorine-containing carbon material, and an object thereof is to provide a method for producing a higher performance material and / or a production method with higher productivity.

The inventor can produce a fluorine-containing carbon material (a step of forming a solid material containing fluorine and carbon from a gas phase, a step of applying a predetermined treatment to a material to be treated containing fluorine and carbon, and the like). The present inventors have found that the characteristics of the resultant product can be effectively adjusted by performing a treatment of causing the accelerated gas particles to collide in the presence of H ₂ O gas. The present invention has been made based on such knowledge.

The technique disclosed here is a carbon material containing fluorine (hereinafter, also referred to as “CF material”. Typically, the carbon material exhibits a solid state at room temperature (for example, 25 ° C.) under normal pressure). It relates to a method of manufacturing. The CF material manufacturing method includes the following steps: (A) depositing a source gas containing fluorine and carbon on a substrate from a gas phase to form a deposit containing fluorine and carbon, wherein the source gas is And depositing the source gas in a predetermined atmospheric gas while colliding gas particles accelerated toward the base material against the deposition surface in at least a part of the period during which the gas is deposited; and (B) At least one of a step of causing a gas particle accelerated toward the surface to collide with the surface of the material to be treated containing fluorine and carbon in a predetermined atmosphere gas. The predetermined atmospheric gas in the steps (A) and (B) is as follows: (1) an atmospheric gas adjusted by adding H ₂ O; and (2) H ₂ O as a main component. A gas that satisfies at least one of atmospheric gases.

  According to such a method, the characteristics of the CF material (resultant) can be effectively adjusted by causing accelerated gas particles to collide in an atmospheric gas in which moisture is intentionally present. This makes it possible to produce higher performance CF materials (for example, higher hardness CF materials, CF materials whose surface properties are locally adjusted, etc.), and according to the above method, the desired performance ( For example, a CF material having hardness) can be manufactured with higher productivity.

Here, the “accelerated gas particles” toward the surface of the base material or the material to be processed means that the movement of the gas particles as a whole is larger than the random thermal motion, and the surface of the base material or the material to be processed. It means being promoted (accelerated) in the direction toward. As a method for obtaining gas particles accelerated in this way (hereinafter, also referred to as “accelerated particles”), for example, charged particles (which may be plasma source gas and / or H ₂ O) may be used. A method of accelerating (that is, electromagnetic acceleration) toward the surface of the substrate or the material to be processed by electromagnetic force can be preferably employed. As another method of accelerating charged particles, a method of accelerating the particles by electrostatic force is exemplified. It is preferable that the angle formed between the normal line of the surface of the substrate or the material to be processed and the acceleration direction of the gas particles is generally within ± 60 ° (more preferably within ± 30 °). By this, the effect (for example, the effect which adjusts the characteristic of a result) by making a gas particle collide can be exhibited more efficiently. For example, the gas particles accelerated in the direction in which the angle is substantially 0 ° (that is, the normal line and the acceleration direction of the gas particles are substantially parallel) may collide.

In one embodiment of the technology disclosed herein, the predetermined atmospheric gas is depressurized (typically less than 1 × 10 ⁻⁴ Torr, preferably in the chamber used in the step (A) or the step (B), preferably 0.5 × 10 ⁻⁴ Torr or less) and then H ₂ O is supplied into the chamber. According to this aspect, an operation of discharging excess gas (such as oxygen in the air) or volatile dirt that may exist in the chamber, and an atmosphere containing moisture by intentionally introducing H ₂ O into the chamber The operation of adjusting the gas can be efficiently performed as a series of operations.

  In one embodiment of the technology disclosed herein, the source gas in the step (A) is a solid organic material containing fluorine (typically a polymer having a main chain based on carbon-carbon bonds as a main component. The organic polymer material) is obtained by gasification (for example, sublimation). As described above, the use of a solid organic material with good handleability (hereinafter sometimes referred to as “solid resin material”) as a source for generating a raw material gas is useful for carrying out the CF material manufacturing method disclosed herein. This is advantageous in reducing the size and simplification of the apparatus used.

  In one embodiment of the technology disclosed herein, the source gas in the step (A) is obtained by forming plasma from the material by applying discharge energy to the solid organic material (solid resin material) containing fluorine. It is what was done. Typically, the surface of the solid resin material is heated by a discharge current so that the material is gasified (for example, sublimated) from the surface portion, and at least a part of the gasified product is ionized to generate plasma from the solid resin material. Form. In this way, the source gas at least partially converted into plasma is deposited (evaporated) on the substrate to form a deposit containing fluorine and carbon. According to this aspect, since a solid resin material with good handleability is used as a raw material and discharge energy is used, an apparatus configuration suitable for simplification and miniaturization (for example, a high power device such as a laser generator is required) Without) the plasma can be efficiently formed from the solid resin material.

  The method disclosed herein can be implemented in an embodiment in which the deposit in the step (A) is a carbonaceous film containing fluorine (referred to a film containing carbon as a main component and fluorine as a subcomponent). For example, in the form in which the deposit is a DLC film containing fluorine, the deposit can be preferably applied to the production of a DLC film containing fluorine. For example, it is suitable as a method for producing a fluorine-containing carbonaceous film (typically DLC film) having a hardness of about 5 GPa or more (typically about 5 to 100 GPa, for example 5 to 30 GPa).

In this specification, “DLC (diamond-like carbon)” is a concept indicating an amorphous carbonaceous material having a basic structure (basic skeleton) with a carbon network including SP ³ bonds and SP ² bonds. . The ratio of SP ³ bond and SP ² bond is not particularly limited. For example, DLC in which the proportion of SP ³ bonds is in the range of about 10 to 90% is a typical example included in the DLC here. DLC consisting essentially of carbon, DLC consisting essentially of carbon and hydrogen, DLC containing elements other than hydrogen (heterogeneous elements) in addition to carbon are all in the concept of DLC here. May be included. Regardless of the form of the dissimilar element in the DLC containing the dissimilar element, for example, a structure in which a part of C constituting the network is replaced with a dissimilar element, or one of H bonded to C constituting the network. It may be a DLC such as a structure in which part or all is substituted with a different element. The different elements may be one or two or more selected from elements such as fluorine, nitrogen, and boron. Further, in the present specification, the fluorine-containing DLC refers to DLC containing at least fluorine in addition to carbon and hydrogen, and further includes a different element other than fluorine and substantially does not include such a different element. It is the meaning which includes both.

The fact that the fluorine-containing carbonaceous film (typically fluorine-containing DLC film) obtained through the step (A) has the basic structure can be grasped by, for example, observing the Raman spectrum of the resultant product. . For example, the ID / IG ratio obtained from the intensity (ID) of the D peak appearing near 1350 cm ⁻¹ (D band) and the intensity (IG) of the G peak appearing near 1550 cm ⁻¹ (G band) in the Raman spectrum, and Based on the position of the G peak, the amorphization trajectory method proposed by Ferrari et al. (Reference: Phys. Rev. B 61, 14095-14107 (2000), Interpretation of Raman spectra of disordered and amorphous carbon, AC Ferrari and J Robertson) can estimate the proportion of sp ³ bonds contained in the carbonaceous film. In addition, as a method for measuring the hardness of a resultant product (for example, a fluorine-containing DLC film) obtained through the step (A), for example, a general nanoindentation method can be preferably employed. Moreover, it can be grasped | ascertained that the said result contains the said different element (for example, fluorine) by performing the Auger electron spectroscopy analysis of this result, for example.

  In one aspect of the technology disclosed herein, the fluorine content on the surface of the material to be treated (for example, a solid resin containing fluorine) is reduced by the step (B). According to this aspect, it is possible to produce a fluorine-containing carbon material in which the fluorine content in the vicinity of the surface is locally reduced, and thereby surface characteristics derived from fluorine (for example, water repellency, low friction coefficient, etc.) are suppressed. .

It is explanatory drawing which shows typically the structural example of the apparatus used for the CF material manufacturing method including a process (A). It is explanatory drawing which expands a part of FIG. 1 and shows the structure and operation | movement typically. It is a characteristic view which shows the Raman spectrum of sample A11. It is a characteristic view which shows the Raman spectrum of sample A12. It is explanatory drawing which shows typically the structural example of the apparatus used for the CF material manufacturing method including a process (B). It is a characteristic view which shows IR spectrum of sample B0-B4.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and the drawings and common general technical knowledge in the field.

  In order to facilitate the understanding of the technology disclosed herein, first, a solid organic material containing fluorine is used as a raw material gas source, and plasma of the raw material gas is formed from the solid organic material to form a fluorine-containing DLC. Although the description will be made mainly assuming the case of manufacturing a film (CF material), the application object and the embodiment of the technology disclosed herein are not intended to be limited thereto.

  In one embodiment of the CF material manufacturing method disclosed herein, fluorine is used as a source of a source gas (at least part of which may be a plasma gas) used for forming a deposit containing fluorine (F) and carbon. (Solid organic material at least at room temperature (for example, 25 ° C., typically containing other elements such as hydrogen (H) in addition to fluorine and carbon)). The use of a solid organic material (solid resin material) containing a polymer having a main chain based on a carbon-carbon bond and containing fluorine is preferred. Such a fluorine-containing polymer (typically substantially insulating) is a concept including gasification (vaporization, sublimation, decomposition (for example, thermal decomposition, depolymerization), etc.) when heated by discharge or the like. Polymers that are easy to do are preferred. A polymer showing the property of being easily sublimated by heating is preferred. Also preferred are polymers that have a low tendency to burn when heated (carbide remains on the surface). The solid organic material containing such a fluorine-containing polymer is suitable for smoothly gasifying (preferably sublimating) in order from the outermost surface using discharge energy.

  Examples of the source gas source include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and ethylene-tetrafluoro. A solid resin material containing a fluororesin such as ethylene copolymer (ETFE), polyvinylidene fluoride (PVdF), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE) is preferably used. be able to. It is preferable to use a solid resin material containing such a fluororesin as a main component (a component occupying 50% by mass or more). In a preferred embodiment of the technology disclosed herein, a solid resin material substantially made of a fluororesin (for example, PTFE) is used as a source gas source.

  As the source gas source, a fluorine-containing organic compound and another solid organic compound (typically an organic polymer) may be used in combination. Examples of source gas sources that can be used with fluorine-containing organic compounds include aromatic vinyl resins such as polystyrene and poly α-methylstyrene, olefin resins such as polyethylene and polypropylene, polyacetylene, polyacetal, polyimide, polyvinyl chloride, polycarbonate ( PC), polyphenylene sulfide (PPS), polyether ether ketone (PEEK) and other organic polymers; adamantane and its derivatives or analogs (eg, diadamantane) and other organic compounds; The source gas source may contain materials other than solid organic compounds (organic compounds that exhibit a liquid state at room temperature, metal fine particles, and the like). Such raw materials include various methods such as obtaining (purchasing) commercially available materials, appropriately processing (mixing, molding, etc.) the commercially available materials, and synthesizing (polymerizing, etc.) by known methods. Can be prepared.

  In one embodiment of the technology disclosed herein, plasma of the source gas is formed from the material by applying discharge energy to a solid resin material (for example, PTFE) as a source gas source. For example, plasma is formed by gasifying the material by discharge (surface discharge) along the surface of the material and ionizing at least a part of the gasified product. In a preferred embodiment, the creeping discharge initiates gasification and plasma formation of the solid resin material, followed by another form of discharge (a form in which current flows in the gasified product and / or plasma generated by the creeping discharge). Gas discharge and plasma formation of the solid resin material is continued.

  The application of the discharge energy is preferably performed non-stationarily (typically in a pulse form). Thus, plasma can be efficiently generated from the solid resin material while suppressing the energy cost. Further, in the method of accelerating the plasma using a self-induced magnetic field described later, the plasma is more effectively electromagnetically accelerated by such unsteady discharge (for example, by repeating an operation in which a large current flows instantaneously). Can do. From the viewpoint of energy cost and acceleration efficiency when performing electromagnetic acceleration of plasma, it is preferable to perform the discharge so that a large current flows in a short time.

  Forming plasma from a solid resin material by applying discharge energy as described above causes discharge (creeping discharge, for example, pulse creeping discharge) along the surface of the solid resin material, and the discharge current causes the discharge to occur. Gasifying (eg, sublimating) the solid resin material from the surface portion and ionizing at least a part of the gasified product to form plasma. Further, the gasification product of the solid resin material and / or the plasma formed by ionization of the gasification product (typically, the gasification product generated by the creeping discharge and / or the gasification product was formed by ionization. Generating a discharge (for example, arc discharge, preferably pulsed arc discharge) flowing through the plasma), gasifying the solid resin material by the discharge current, and ionizing at least a part of the gasified product Forming plasma (in other words, forming a plasma-containing gas in which at least a part of the gasified product generated from the solid resin material is converted into plasma). For example, first, discharge energy is imparted to the solid resin material by the creeping discharge, and then the discharge is in a form in which a current flows in the gasified product and / or plasma (this may be a discharge that is triggered by the creeping discharge). It may be an embodiment in which gasification and plasma formation of the solid resin material are continued by applying discharge energy.

  In a preferred aspect of the technology disclosed herein, the formed plasma is accelerated toward the substrate (preferably accelerated by electromagnetic force, that is, electromagnetic acceleration). According to this aspect, the generated plasma (plasma constituent component) can be more appropriately deposited on the base material (the surface of the base material arranged to face the plasma acceleration direction). When the technique disclosed herein is applied to the production of a fluorine-containing DLC film, it is particularly meaningful to perform the acceleration (typically electromagnetic acceleration). That is, it is preferable to arrange the substrate in a range where the accelerated plasma is irradiated. In a preferred embodiment, a range within approximately 60 ° with respect to the plasma acceleration direction (typically, the center of gravity of the discharge surface of the solid resin material is the apex, and the plasma acceleration direction (acceleration vector) is a vertical line. The base material is placed in a cone having an apex angle of 60 ° or less. More preferably, the angle is approximately within 30 ° (for example, approximately 0 °).

  The acceleration of the plasma by the electromagnetic force is, for example, the electromagnetic force (J × B) applied to the charged particles in the plasma by the interaction between the current J flowing along with the discharge and the magnetic field (self-induced magnetic field) B induced by the current. ) Can be realized. Further, instead of the self-induced magnetic field or in addition to the self-induced magnetic field, the plasma may be electromagnetically accelerated using an external magnetic field generated from a permanent magnet, an electromagnetic coil or the like.

In the step (A) in the CF material manufacturing method disclosed herein, usually, at least in a chamber surrounding a region from the surface of the solid resin material as a source gas source (where the source gas is generated from the material) to the substrate surface (Typically, a source gas source and a substrate are disposed inside the chamber.) A source gas is deposited on the substrate. In a preferred embodiment, the atmospheric gas in the chamber is (1) an atmospheric gas in which H ₂ O is added to increase the H ₂ O partial pressure and / or (2) an atmospheric gas containing H ₂ O as a main component. Under certain conditions and accelerated gas particles (accelerated particles) toward the substrate are deposited surfaces (typically the surface of the deposit that is being formed; The source gas is deposited on the substrate while colliding with the substrate.

The accelerated particles can be various gas particles. For example, in an embodiment in which the source gas plasma is accelerated (typically electromagnetic acceleration) toward the substrate and the source gas is deposited on the substrate, the accelerated source gas plasma is used as the accelerated particles. can do. The acceleration particles may be ones in which gas particles (referring to gas particles other than the source gas) constituting the atmospheric gas are accelerated (typically electromagnetic acceleration) toward the base material. For example, charged particles derived from H ₂ O in the atmospheric gas (which may be H ₂ O plasma) can be used as the accelerated particles. Other gas particles that can be used as the acceleration particles include gas particles other than H ₂ O that can constitute an atmospheric gas (typically, charged particles derived from an inert gas such as N ₂ , Ar, Ne, etc. Plasma of the inert gas).

  In the step (A), the accelerated particles that collide with the deposition surface have energy equivalent to three times or more the electron temperature (typically about 1 to 2 eV) when the particles are in a random thermal motion state. It is preferable. For example, it is preferable to collide accelerated particles having energy of approximately 5 eV or more (typically 10 eV or more). According to this aspect, the effect by applying the technique disclosed herein (for example, at least one of the effect of improving the hardness of the deposit and the effect of forming the deposit having a desired hardness at a higher rate) Can be better realized. The energy of the accelerated particles that collide with the deposition surface (that is, the energy of the accelerated particles immediately before the collision) can be grasped by, for example, a Faraday cup.

In the art disclosed herein, the atmosphere gas satisfying the (1) and / or (2) is different from the case of adjusting the atmosphere for depositing a raw material gas by a conventional normal operation, intentionally H ₂ O Is the atmosphere gas. Here, the normal operation refers to an operation that is performed without intention of causing H ₂ O to actively exist in the atmospheric gas. By simply exhausting the gas (typically air) in the chamber using a general decompression pump, which is adjusted to exclude H ₂ O and other gases without any particular distinction. An atmosphere gas adjusted by reducing the pressure in the chamber to an appropriate pressure, or a gas substantially free of H ₂ O such as dry nitrogen gas or dry argon gas after the pressure reduction is supplied into the chamber to reduce the degree of pressure reduction. The atmospheric gas and the like adjusted is a typical example included in the “atmospheric gas adjusted by normal operation” herein.

The atmospheric gas satisfying at least one of the above (1) and (2) (hereinafter also referred to as “atmospheric gas in which H ₂ O is present”) may be, for example, a gas in the chamber (typically Can be adjusted by introducing (adding) H ₂ O into the chamber after exhausting the air) and reducing the pressure in the chamber to an appropriate pressure. H ₂ O added (supplied) into the chamber may be in any state of gas (H ₂ O gas, that is, water vapor), liquid, or solid. Since it is suitable for adjusting the atmospheric gas with higher accuracy, normally, a mode in which H ₂ O gas previously vaporized outside the chamber is supplied into the chamber can be preferably employed. Alternatively, H ₂ O may be added to the atmospheric gas by introducing a gas containing water (intentionally moistened air (for example, air mixed with water vapor), moist nitrogen gas, etc.) into the chamber. Good. As another method for adjusting the atmospheric gas containing H ₂ O, a part or all of the gas in the chamber may be a gas having a higher partial pressure of H ₂ O gas than the gas (substantially H ₂ O gas). And a method of reducing the pressure in the chamber to an appropriate pressure after the replacement, and the like.

Thus, (which may be an atmosphere gas consisting substantially of H _{2 O.)} Ambient gas moistened of H 2 _O intentionally above (A) depositing a material gas while colliding accelerated particles in a According to the present invention, a harder deposit (typically a fluorine-containing carbonaceous film, for example, a fluorine-containing DLC film) is formed as compared with the case where the source gas is deposited in the atmospheric gas adjusted by the normal operation. Can be formed. In general, when the deposition rate of the source gas is increased, the hardness of the deposit tends to decrease. According to the step (A), the deposit having a desired hardness (in the atmospheric gas adjusted by the normal operation) Can be a deposit having a hardness equal to or higher than that in the case where the source gas obtained in (1) is deposited.) Can be formed at a higher deposition rate.

In the step (A), at least a path (typically in the chamber) from the surface of the solid resin material (source gas generation location) as a source gas source to the substrate surface is maintained in a reduced pressure environment. Can be preferably implemented. For example, it is preferable that plasma is generated under the reduced pressure environment and the plasma is deposited on the substrate under the reduced pressure environment. The degree of pressure reduction in the step (A) (refers to the pressure of the atmospheric gas containing H ₂ O and does not include the pressure increase due to the generation of the raw material gas) is, for example, 1 × 10 ⁻⁵ to 1 × 10 ⁻² Torr. In general, it is appropriate to set it to about 5 × 10 ^{−5 to} 5 × 10 ⁻³ Torr (for example, 1 × 10 ⁻⁴ to 1 × 10 ⁻³ Torr). Of the total pressure of the atmospheric gas, the partial pressure of H ₂ O is typically 30% or higher, preferably 50% or higher, more preferably 75% or higher (eg 90% or higher). It may be 100%. If the pressure of the atmospheric gas is too low, the amount of H ₂ O present in the atmospheric gas may be insufficient, and the effect of improving the hardness and / or deposition rate of the deposit may not be sufficiently exhibited.

The above step (A), if the atmospheric gas in the presence of the H _{2 O,} also be implemented in the pressure conditions other than the above reduced-pressure environment. For example, the plasma may be generated and deposited on the base material in an atmospheric gas at normal pressure. Here, if other conditions (discharge conditions, acceleration conditions, etc.) are the same, the mean free path of the accelerated particles tends to become shorter as the pressure of the atmospheric gas increases. Therefore, from the viewpoint that the effect of improving the hardness and / or the deposition rate of the deposit can be sufficiently exhibited without excessively narrowing the degree of freedom of selection of other conditions, usually, the atmospheric gas in the step (A) is normally used. It is appropriate to set the pressure to 1 × 10 ⁻² Torr or less (that is, approximately 1.3 Pa or less). The partial pressure of H ₂ O in the atmospheric gas is preferably 5 × 10 ⁻³ Torr or less (for example, 1 × 10 ⁻³ Torr or less).

  Although it does not specifically limit, In the aspect which provides discharge energy to the solid resin material containing fluorine, and forms plasma from this material, the application of the discharge energy is, for example, a discharge time of one time (one shot). The discharge can be preferably carried out in such a manner that the discharge time is about 1 μsec to 50 μsec (more preferably about 4 μsec to 10 μsec). Moreover, it can implement preferably in the aspect by which the said discharge is performed so that the peak value of discharge current may be about 1 kA-about 30 kA (more preferably about 5 kA-10 kA). The interval at which the discharge is performed can be, for example, about 0.1 to 10000 times per second, and is usually about 1 to 100 times (preferably 1 to 30 times). If the discharge interval is too short, the hardness of the formed deposit tends to be low. If the discharge interval is too long, the amount of raw material gas formed per unit time decreases, and the deposit formation rate (and hence the productivity of the CF material) tends to decrease. The discharge voltage can be about 600V to 3000V (preferably about 800V to 1200V). In a mode in which the electric charge stored in the capacitor is discharged, the capacitance of the capacitor can be, for example, about 0.1 μF or more (typically about 0.1 μF to 1000 μF), and usually about 1 μF or more (for example, It is preferably about 1 μF to 100 μF. A preferable range of the amount of charge related to one-shot discharge can be a range derived from the above-described preferable capacitor capacity and voltage.

The preferable range of energy released by one shot of discharge is the contents of the atmospheric gas (for example, H ₂ O partial pressure) when depositing the source gas on the substrate surface, and the physical properties (for example, hardness) of the CF material to be manufactured. ), The type of source gas source (solid resin material) used, the size of the source gas source, the distance between the electrodes, the arrangement of the substrate (distance from the source gas source surface to the substrate surface, the direction of electromagnetic acceleration, The angle may vary depending on the angle between the substrate surface and the like. For example, in the step (A), the H ₂ O partial pressure of the atmospheric gas is 75% or more, the total pressure is about 1 × 10 ⁻⁵ to 1 × 10 ⁻² Torr, and the discharge energy is supplied to PTFE as the source gas source. When a substrate is arranged at a position within 30 ° from the electromagnetic acceleration direction of the plasma formed by applying a fluorine and a fluorine-containing DLC film is produced on the surface of the substrate, the energy per shot is about 0. By setting it to about 1J to 10J (preferably about 0.5J to 5J), a suitable result can be realized. If the energy is too high, the hardness of the deposit formed tends to be low. If the energy is too low, the amount of raw material gas formed by one-shot discharge decreases, and the deposit formation rate tends to decrease.

In implementing the technique disclosed herein, it is not necessary to clarify the reason why the hardness and / or deposition rate of the deposit can be improved by the step (A), but the following may be considered. That is, when the accelerated particles in an atmospheric gas was present and H 2 _O (at least a part can be a plasma raw material gas particles.) Depositing a material gas while collision, H ₂ O in the atmospheric gas Can be adsorbed on the deposition surface, and the C—F bonds can be relaxed by hydrogen bonding of H ₂ O molecules to fluorine atoms forming C—F bonds on the deposition surface. The F atoms constituting the relaxed C—F bond are in a state of being easily desorbed by impact or the like (a state in which the desorption rate is improved). When accelerated particles (typically charged particles) collide with such F atoms, a part of the F atoms is desorbed with a higher probability than the case where H ₂ O molecules are not adsorbed due to the impact. Further, once the F atoms desorbed are trapped by H ₂ O molecules in the atmospheric gas, the F atoms are prevented from recombining with the deposition surface. According to the step (A), an impact caused by collision of accelerated particles is applied to the deposition surface in an atmospheric gas in which H ₂ O is present, whereby a part of F atoms is efficiently removed from the deposition surface by the mechanism. Presumed to be (detached). Thus, it is considered that the amount of fluorine contained in the deposit is appropriately controlled (suppressed) and the hardness of the deposit is improved.

According to the step (A), for example, H ₂ O is not substantially present (for example, compared with the case where the source gas is deposited in an atmospheric gas in which the partial pressure of H ₂ O is 1 × 10 ⁻⁵ Torr or less). A deposit having a reduced fluorine content (typically a fluorine-containing carbonaceous film such as a fluorine-containing DLC film) and a deposit having a higher hardness can be formed. In addition, a deposit having a reduced fluorine content and having a hardness equal to or higher than that in the case where the source gas is deposited in an atmospheric gas substantially free of H ₂ O is higher. It can be formed at a deposition rate.

In addition, the effect (effect which improves the hardness and / or deposition rate of a deposit) resulting from the fluorine desorption mechanism mentioned above can be exhibited similarly irrespective of the property of the source gas source. Therefore, the technique disclosed here is not limited to an embodiment using a solid organic material as a source gas source, and is similarly implemented in an embodiment in which a CF material is produced using a liquid or gas as the source gas source. It is understood that a similar effect can be expressed. The production of a CF material (typically a fluorine-containing carbonaceous film, preferably a fluorine-containing DLC film) to which the step (A) is applied is performed by, for example, an atmospheric gas in which H ₂ O is present in the plasma CVD method described above. Embodiment in which plasma of source gas containing fluorine and carbon is accelerated and deposited on a substrate; a solid organic material containing fluorine and carbon is used as a target, and the target is vaporized by laser ablation (typically sublimation) A mode in which source gas particles (particles to be sputtered) are accelerated and deposited on the substrate; the particles to be sputtered obtained by irradiating the target with ions in magnetron plasma are accelerated and deposited on the substrate. A mode in which particles to be sputtered obtained by irradiating the target with an ion beam are accelerated and deposited on a substrate; It can be.

  In addition, from the above-described fluorine desorption mechanism, the effect of the present invention due to this mechanism is that the particles that collide with the relaxed F atom of the C—F bond are particles other than source gas particles (for example, charged particles). Is understood to be able to be exerted as well. Therefore, the production of the CF material to which the step (A) is applied utilizes, for example, gas particles (may be neutral particles or ions) in an atmospheric gas as the acceleration particles. Embodiments: Embodiments in which an ion beam (for example, a beam of argon ions) is irradiated on the deposition surface;

  According to the CF material manufacturing method including the step (A), CF materials having various thicknesses can be manufactured on the substrate. Although not particularly limited, the above technique can be preferably applied to the production of a fluorine-containing carbonaceous film (for example, a fluorine-containing DLC film) having a thickness of about 1 nm to 10 μm, for example. As a base material for forming such a carbonaceous film, an appropriate one may be selected according to the purpose, and the material, shape, etc. of the base material are not particularly limited. For example, a substrate similar to the substrate used as a film formation target in a conventional plasma CVD method or the like can be used.

The step (A) in the technique disclosed herein is a distance (hereinafter referred to as the source gas) until the source gas particles fly in the atmosphere gas in which the H ₂ O is present and deposit on the substrate. This is preferably performed under the condition that D1 is equal to or longer than the mean free path D2 of the source gas in the atmospheric gas (that is, the condition that D1 ≧ D2). obtain. The flight distance D1 of the source gas is the distance from the surface of the solid organic material to the surface of the base material in the embodiment in which the solid organic material is sublimated in the chamber to generate the source gas (the source gas is accelerated between the electrodes). In this embodiment, the distance from the tip of the electrode to the surface of the base material is equivalent to the distance from the target surface to the surface of the base material. Under the condition of D1 <D2, when the source gas particles collide with atmospheric gas particles (typically H ₂ O molecules), the number of source gas particles reaching the deposition surface is reduced, and the deposit formation rate is reduced. May be reduced. In the embodiment in which the source gas particles are also used as the accelerated particles, it is particularly significant to perform the step (A) under the condition of D1 ≧ D2. In such an embodiment, if D1 <D2, the accelerated source gas particles collide with the atmospheric gas particles (typically H ₂ O molecules) until the accelerated source gas particles reach the deposition surface, thereby losing momentum. The effect of desorbing F atoms from the deposition surface may not be sufficiently exerted. The mean free path D2 is such that the pressure of the atmospheric gas, the H ₂ O partial pressure in the atmospheric gas, and the energy that the source gas has when it is generated (for example, D2 tends to increase as the energy per shot increases as described above). ), The degree of acceleration of source gas particles, the type of source gas particles, and the like. In consideration of these, each condition may be set so that D1 ≧ D2.

Next, the step (B) will be described.
The present inventor has described that the fluorine desorption mechanism described above is not limited to desorbing fluorine from the deposit when forming the deposit from the source gas while colliding with the acceleration particles in the atmosphere gas in which H ₂ O is present. This also works in the same manner when accelerating particles collide with the surface of a solid material (processing material) containing fluorine and carbon in an atmosphere gas in which H ₂ O is present. We thought that it could be desorbed efficiently. As a typical aspect of the step (B) in the technology disclosed herein, accelerated particles (here, plasma) collide with the surface of PTFE (material to be processed) in an atmospheric gas in which H ₂ O is present. As a result, it was confirmed that the C—F bond on the PTFE surface was cleaved and fluorine could be eliminated.

  According to the step (B) in the technology disclosed herein, surface properties derived from fluorine in the vicinity of the surface (for example, by reducing the fluorine content in the vicinity of the surface of the material to be treated containing fluorine and carbon (for example, CF materials with suppressed water repellency, low friction coefficient, etc. can be produced. The material to be treated can be various solid organic materials containing fluorine. For example, the fluororesin exemplified as the solid organic material that can be used for the source gas source in the above-described step (A) can be preferably employed as the material to be treated in the step (B). The material to be treated can also be a carbonaceous material containing fluorine (for example, a DLC film containing fluorine). For example, the deposit obtained in the step (A) may be used as a material to be processed, and the surface thereof may be processed in the step (B).

The atmospheric gas in the step (B) is an atmospheric gas that satisfies the above (1) and / or (2) (that is, an atmospheric gas in which H ₂ O is present), similar to the atmospheric gas in the step (A), (A) It can adjust preferably by the same operation as a process. This step (B) can be preferably carried out in a mode in which at least the surface of the material to be treated is maintained in a substantially atmospheric or reduced pressure environment. When the step (B) is performed under a reduced pressure environment, the degree of the reduced pressure can be, for example, 1 × 10 ⁻⁵ Torr or more (typically 500 Torr or less), and usually 1 × 10 ⁻³ Torr. It is appropriate to set it above (preferably 1 × 10 ^{−3 to} 10 Torr, for example, 1 × 10 ^{−2 to} 1 Torr). Of the total pressure of the atmospheric gas, the partial pressure of H ₂ O is typically 30% or higher, preferably 50% or higher, more preferably 75% or higher (eg 90% or higher). It may be 100%. If the pressure of the atmospheric gas is too low, the amount of H ₂ O present in the atmospheric gas may be insufficient, and the treatment effect by the step (B) may not be sufficiently exhibited. The gas other than H ₂ O constituting the atmospheric gas can be, for example, an inert gas such as N ₂ , Ar, or Ne.

As the accelerated particles (accelerated gas particles) in the step (B), H ₂ O molecules in the atmospheric gas, molecules other than H ₂ O that can be included in the atmospheric gas (for example, N ₂ , Ar, Ne, etc.) Inert gas molecules), charged particles formed by ionization (for example, plasma) of these molecules, and the like can be used. Since it is easy to accelerate toward the surface of the material to be treated, charged particles can be preferably used as the accelerated particles. As a method for accelerating gas particles and a method for causing the accelerated particles to collide with a substrate, for example, by applying an RF bias to the substrate, the charged particles in the atmospheric gas are accelerated toward the substrate side, and the substrate surface And a method of irradiating an ion beam (for example, an argon gas beam).

  The processing time in the step (B) can be appropriately adjusted so that a desired processing effect is realized. Usually, the treatment time is suitably 1 second or longer, preferably 5 seconds or longer. If the treatment time is too short, it may be difficult to obtain a sufficient treatment effect. The upper limit of the processing time is not particularly limited. Usually, it is appropriate to set the treatment time to 1 hour or less. If the treatment time is longer than necessary, inconveniences such as an increase in energy cost required for the treatment, a reduction in productivity of the CF material, and a deterioration of the surface of the CF material may occur.

  The step (A) can be preferably performed using, for example, a CF material manufacturing apparatus having the following configuration. The CF material manufacturing apparatus may include a raw material holder that holds a solid organic material (solid resin material) as a raw material gas source. Moreover, the discharge means comprised so that a plasma could be formed from this material by providing discharge energy to the said solid organic material can be provided. The discharging means typically includes a pair of electrodes and a voltage applying means for applying a voltage between the electrodes. One or both of the pair of electrodes may be configured to also serve as the raw material holder or a constituent member thereof (for example, a configuration in which the solid resin material is held between the pair of electrodes). The apparatus may further include a substrate holder that holds a substrate on which the source gas is deposited. Further, it may include atmosphere adjusting means for adjusting the vicinity of at least the surface (typically, the surface facing the source gas source) of the base material to the atmospheric gas environment corresponding to the above (1) and / or (2).

The apparatus typically includes a chamber that houses a raw material holder and a substrate holder. In such embodiments, the atmosphere adjuster may comprise of H _{2 O} supply section for supplying of H _{2 O} into the chamber. The H ₂ O supply unit includes, for example, an H ₂ O storage unit that stores liquid H ₂ O, an H ₂ O gas generation unit that heats and vaporizes H ₂ O drawn from the storage unit, and the H ₂ O contact the _{2 O} gas generating unit and the chamber may comprise of H _{2 O} supply pipe for supplying the H _{2 O} gas into the chamber. The atmosphere adjusting means may further include a gas exhaust pipe that exhausts the gas in the chamber and a vacuum pump. It may also include a pressure gauge that detects the pressure in the chamber.

  In a preferred embodiment, the discharging means is configured to generate a discharge (a creeping discharge, preferably a pulse creeping discharge) along at least the surface of the solid resin material. Furthermore, the creeping discharge may be configured to generate a discharge (for example, arc discharge, preferably pulsed arc discharge) in which a current flows through the plasma generated by the creeping discharge. As long as such discharge means can be constructed, the shape and arrangement of the electrodes are not particularly limited. For example, the two plate-like electrodes may be arranged in parallel or non-parallel. Alternatively, a pair of electrodes may be arranged coaxially.

  The apparatus may further include electromagnetic acceleration means for accelerating the formed plasma by an electromagnetic force in a direction toward the substrate. In a preferred embodiment, at least a part of the pair of electrodes protrudes outward from the organic material (preferably, protrudes from the material to the side where the base material is disposed) and is provided in a shape facing each other. It has been. For example, the material (solid resin material) is disposed between parallel plate electrodes, and the electrode extends from the solid resin material in the longitudinal direction (preferably the substrate side) and extends substantially in parallel. it can. Further, a solid resin material may be disposed between the outer electrode and the inner electrode of the coaxial electrode, and the electrode may extend from the solid resin material in the axial direction (preferably on the substrate side) and extend. The electromagnetic acceleration means is preferably formed so as to electromagnetically accelerate plasma in the direction between the protruding electrodes by a self-induced magnetic field generated in association with the discharge.

  The apparatus disclosed herein includes a capacitor in which the voltage applying means is connected between the pair of electrodes, and is configured such that plasma is formed from the material by discharging electric charge stored in the capacitor. It can be. The discharge may be a creeping discharge or may be a discharge other than the creeping discharge (for example, arc discharge), and both of them (for example, the creeping discharge and the arc discharge generated following the creeping discharge). It may be a discharge of a form including.

  The apparatus disclosed herein can include discharge timing control means for controlling the timing of discharge along the surface of the material (that is, creeping discharge that short-circuits the pair of electrodes). The discharge timing control means may include an igniter that induces the discharge (for example, discharge of the charge stored in the capacitor). The igniter may induce the discharge (for example, creeping discharge) by temporarily increasing the conductivity between the pair of electrodes. In a preferred aspect, the igniter causes a micro discharge (trigger discharge) between the electrodes, and the micro discharge induces a discharge (main discharge) of charges stored in the capacitor.

  Hereinafter, a configuration example of a CF material manufacturing apparatus that can be used in the method disclosed herein and a manufacturing example of a CF material using the apparatus will be described with reference to the drawings. It is not intended to be limited to.

<Configuration example (1) of CF material manufacturing apparatus>
One structural example of a CF material manufacturing apparatus that can be preferably used for the implementation of the step (A) is shown in FIG. The apparatus 1 includes a pair of plate-like electrodes (electrode plates) 12 and 14 and a voltage applying unit 20 that applies a voltage to these electrodes. These constitute the discharge means 10 for applying discharge energy to the source gas source 50 sandwiched between the electrodes 12 and 14.
The electrodes 12 and 14 are strip-shaped plates made of a conductive material such as copper (Cu), and are arranged to face each other substantially in parallel with a predetermined interval. A source gas source 50 made of an insulating solid resin material (for example, PTFE) is sandwiched between the electrodes 12 and 14. That is, in this embodiment, the electrodes 12 and 14 also have a function as a raw material holder. The source gas source 50 is disposed so as to be biased toward one end side in the longitudinal direction of the electrodes 12 and 14. The other ends of the electrodes 12 and 14 extend from the source gas source 50 and extend. In front of the protruding electrode, the substrate 60 held by the substrate holder 62 is substantially perpendicular to the protruding direction (in other words, the longitudinal direction of the electrode substantially coincides with the normal direction of the substrate 60). ) Is arranged.

The voltage applying means 20 includes a capacitor 22 connected between the electrode 12 and the electrode 14, and a DC power source 24 that is electrically connected in parallel with the capacitor and functions as a charging power source. The DC power source 24 is connected so that the electrode 12 disposed on the upper side in FIG. 1 serves as a cathode and the other electrode 14 serves as an anode when the device 1 is not operated (non-discharged). ing. The electrode (cathode) 12 is grounded. The electrode (anode) 14 is connected to a DC power supply 24 via a limiting resistor 18.
An igniter 16 is installed in the vicinity of the front surface of the source gas source 50 (the surface on the side where the electrodes 12 and 14 protrude, ie, the surface on the substrate 60 side). The igniter 16 is connected to the anode of the igniter power supply 15 via a high-voltage pulse generation source 17 and is configured to be able to generate a micro discharge between the electrodes 12 and 14 at an arbitrary timing.

The apparatus 1 includes a vacuum chamber 3 that accommodates the electrodes (raw material holders) 12 and 14 and the substrate holder 62, and an atmosphere adjusting means 30 that adjusts the atmosphere in the chamber 3. Atmosphere adjuster 30 comprises of _{H 2} O supply unit 32 supplies of _{H 2} O into the chamber 3. The H ₂ O supply unit 32 includes an H ₂ O tank 322 that stores liquid H ₂ O, an H ₂ O gas generation unit 324 that heats and vaporizes H ₂ O drawn from the tank 322, and H ₂ O and communicating the gas generator 324 and the chamber 3 and a _{H 2} O supply pipe 326 for supplying the _{H 2} O gas into the chamber 3. The atmosphere adjusting means 30 further includes a gas discharge pipe 34 and a vacuum pump 36 that are connected to the chamber 3 and discharge the gas in the chamber 3 to the outside. By operating this atmosphere adjusting means 30, the inside of the chamber 3 before the start of discharge becomes an atmospheric gas environment having a pressure of 1 × 10 ⁻⁴ to 1 × 10 ⁻³ Torr with 90% by volume or more of H ₂ O gas. Have been adjusted so that.

Taking the case where the source gas source 50 is PTFE as an example, the operation when the step (A) is performed by the apparatus 1 shown in FIG. 1 will be described with reference to FIG.
(1) By applying a pulsed high voltage from the igniter power supply 15 to the igniter 16, a minute pulse discharge is performed from the tip of the igniter 16. By this discharge (trigger discharge), a part of the source gas source 50 is sublimated and further converted into plasma, whereby a very small amount of plasma is generated between the electrodes 12 and 14.
(2) A highly conductive region is formed between the electrodes 12 and 14 by the plasma. This triggers the electrodes 12 and 14 to be short-circuited (that is, the insulation is broken), and the electric charge stored in the capacitor 22 connected to both electrodes flows all at once, so that the main discharge (typically the raw material) A creeping discharge along the surface of the gas source 50 and a subsequent arc discharge).
(3) The current due to the main discharge energizes and sublimates the source gas source 50 by Joule heating and radiation. A part of the sublimate is ionized to become plasma, and is electromagnetically accelerated in the right direction (downstream direction, arrow F direction) in FIG. 2 by the electromagnetic force generated by the main discharge current and the self-induced magnetic field. The sublimates are also accelerated gastrodynamically by the expansion of the high enthalpy gas.
(4) The plasma is accelerated in the downstream direction by such electromagnetic mechanical and gas mechanical acceleration, and is discharged outside the electrodes 12 and 14 while expanding the discharge region. By depositing the plasma (plasma constituent component) on the surface of the substrate 60, a carbonaceous film containing fluorine (for example, a fluorine-containing DLC film) is formed. Here, since the inside of the chamber is adjusted to the atmospheric gas environment, the deposition of the plasma is caused by charged particles (accelerated particles) contained in the accelerated plasma in the atmospheric gas in which H ₂ O is present. It proceeds while colliding with the deposition surface. In this way, the step (A) is performed.

<Configuration example of CF material manufacturing apparatus (2)>
One structural example of the CF material manufacturing apparatus which can be preferably used for the implementation of the step (B) is shown in FIG. The apparatus 2 includes a pair of plate-like electrodes 72 and 74, a vacuum chamber 4 that accommodates them, and an atmosphere adjusting means 30 that adjusts the atmosphere in the chamber 4. The electrodes 72 and 74 are arranged in parallel so as to face each other with a predetermined interval h3. One of these electrodes 72 is connected to a high frequency power source (RF power source) 76 and the other electrode 74 is grounded. On the electrode 72 on the side to which the high-frequency power source 76 is connected, a fluororesin (for example, PTFE plate) 70 as a material to be processed is disposed.

Atmosphere adjuster 30 comprises of _{H 2} O supply unit 32 supplies of _{H 2} O into the chamber 4. Similar to the apparatus 1 shown in FIG. 1, the H ₂ O supply unit 32 includes an H ₂ O tank 322, an H ₂ O gas generation unit 324, and an H ₂ O supply pipe 326. The atmosphere adjusting means 30 further includes a gas discharge pipe 34 and a vacuum pump 36 for discharging the gas in the chamber 4 to the outside. By operating the atmosphere adjusting means 30, the inside of the chamber 4 is adjusted so as to be an atmosphere gas environment having a pressure of 5 to 50 Torr in which 90% by volume or more is made of H ₂ O gas. In such an atmospheric gas, by applying a power of about 20 to 2000 W to the RF power source 76 and applying an RF bias between the electrodes 72 and 74, at least a part of H ₂ O in the atmospheric gas is turned into plasma, Plasma gas particles can be accelerated to the electrode 72 side (that is, toward the surface of the material 70 to be processed) and collide with the surface of the material 70 to be processed. As a result, at least part of the C—F bonds existing in the vicinity of the surface of the material to be treated 70 can be cut to desorb fluorine atoms, and the fluorine content on the surface of the material to be treated 70 can be reduced.

  Hereinafter, several examples related to the present invention will be described, but the present invention is not intended to be limited to those shown in the specific examples.

<Experimental example 1>
(Preparation of sample A1)
A fluorine-containing carbonaceous film (CF material) sample A1 was manufactured using the CF material manufacturing apparatus 1 having the configuration shown in FIGS. As the source gas source 50, a square columnar PTFE (commercially available PTFE resin cut into the above shape) having a square of 10 mm × 10 mm at the bottom and a height of 20 mm was used. As the electrodes 12 and 14, copper plates having a width of 10 mm, a length of 40 mm, and a thickness of 2 mm were used. These electrodes 12 and 14 were arranged to face each other almost in parallel at an interval of 20 mm, and PTFE 50 was sandwiched therebetween. The distance (effective electrode length, distance h1 shown in FIG. 2) from the surface (front surface) of the PTFE 50 to the tips of the electrodes 12 and 14 was 24 mm. As shown in FIG. 1, the electrode 12 disposed at the upper end of the PTFE 50 is provided with a through hole near the surface (front surface) of the raw material, and the igniter 16 is disposed here. A capacitor 22 having a capacitance of 3 μF is connected to the electrodes 12 and 14, and a DC power supply 24 is connected in parallel with the capacitor.

As the substrate 60, a stainless steel plate having a length of 40 mm, a width of 40 mm, and a thickness of 2 mm was used. In this substrate 60, the longitudinal direction of the electrodes 12 and 14 and the normal direction of the substrate 60 substantially coincide with each other, and an imaginary line connecting the surface center of gravity of the discharge surface of the PTFE 50 and the surface center of gravity of the surface of the substrate 60 is The distance from the front surface of the PTFE (source gas source) 50 to the substrate surface (distance h2 shown in FIG. 2) was 40 mm so as to substantially coincide with the normal direction. Next, the vacuum pump 36 connected to the chamber 3 was operated to discharge the air in the chamber, thereby adjusting the internal pressure of the chamber 3 to 1 × 10 ⁻⁵ Torr or less.

The number of times set so that the total energy becomes 100 kJ, assuming that the discharge interval (shot interval) from the capacitor 22 is 4 Hz, and the energy released by one discharge (energy per shot) is 1.0 J. A fluorine-containing carbonaceous film sample A1 was formed on the surface of the substrate by discharging (that is, 100 × 10 ³ times). Here, the energy per shot (corresponding to the charging energy stored in the capacitor 22 and calculated by the following equation: E = 1/2 CV ² ; using the capacitance C and the charging voltage V of the capacitor 22) Was adjusted to the above value by adjusting the applied voltage (V) from the DC power supply 24. Further, the discharge interval (discharge timing) was controlled by the timing of the minute discharge from the igniter 26. That is, by performing discharge from the igniter 26 at intervals of 0.25 seconds, the subsequent main discharge (discharge of charges stored in the capacitor 22) was generated at intervals of 4 Hz.

(Preparation of sample A2)
In the production of the sample A1, after the air in the chamber 3 is exhausted, water vapor is supplied into the chamber 3 (that is, H ₂ O is added), thereby reducing the internal pressure (atmospheric gas pressure) of the chamber 3 before starting the discharge. It adjusted to 1 * 10 < ^-4 > Torr. Other points were the same as the preparation of Sample A1, and a fluorine-containing carbonaceous film sample A2 was prepared. The supply of the steam was produced by supplying substantially gas consisting of H _{2 O} was carried out by introducing the H _{2 O} supply pipe 326 into the chamber 3 (steam into the chamber 3 after air discharge Same for other samples). Thus, the H ₂ O partial pressure of the atmospheric gas adjusted by substantially supplying only the H ₂ O gas into the chamber 3 after air discharge is at least the total pressure of the atmospheric gas (ie, the internal pressure of the chamber). 90% or more, typically approximately 100%.

(Preparation of sample A3)
In the production of the sample A1, after the air in the chamber 3 was discharged, the atmospheric gas pressure was adjusted to 2.5 × 10 ⁻⁴ Torr by supplying (adding) water vapor into the chamber 3. In other respects, a fluorine-containing carbonaceous film sample A3 was prepared in the same manner as in the preparation of Sample A1.

About these samples A1-A3, the hardness was measured using the nanoindentation method about the film | membrane formed in the center part (position 20 mm from an upper side, 20 mm from a left side) of each board | substrate. The obtained results are shown in Table 1 together with an outline of the production conditions for each sample. For samples prepared in an atmospheric gas prepared by adding H ₂ O, the internal pressure of the chamber (atmospheric gas pressure) before the start of discharge is shown in parentheses.

As shown in Table 1, among the fluorine-containing carbonaceous film samples A1 to A3 formed by depositing source gas plasma accelerated toward the substrate by electromagnetic force on the substrate, H ₂ O was intentionally used. Samples 2 and 3 deposited while colliding the plasma against the deposition surface in an atmospheric gas prepared by adding to the sample are clearly higher in hardness than sample A1 without intentional addition of H ₂ O. Met. More specifically, the hardness of samples A2 and A3 was improved by 20% or more (about 20% to 50%) compared to sample A1. Further, in the range of the atmospheric gas conditions employed in the samples A1 to A3, as the amount of H ₂ O gas contained in the atmospheric gas (that is, the amount of H ₂ O added to the chamber) increases, the film having higher hardness. There was a tendency to form (CF material).

When the Raman spectra of samples A1 to A3 were measured, all were characteristic of DLC, that is, a broad peak (D peak) near 1350 cm ⁻¹ (D band) and a broad peak near 1550 cm ⁻¹ (G band). A spectrum in which a large peak (G peak) was superimposed was observed. Further, from the results of X-ray electron spectroscopy analysis, it was confirmed that samples A1 to A3 all contain fluorine (F) in addition to carbon (C) (that is, a DLC film containing fluorine).

<Experimental example 2>
(Preparation of samples A4 and A5)
In the production of the sample A1, the shot interval was changed to 8 Hz and 16 Hz. In other respects, fluorine-containing carbonaceous film samples A4 and A5 were produced in the same manner as in the production of sample A1.

(Production of samples A6 to A8)
Above in the preparation of the samples A5 (shot interval 16 Hz), after discharging the air in the chamber 3, by supplying steam into the chamber 3, 1 × ¹⁰ -4 Torr atmospheric gas pressure, 5.5 × 10 ^- Adjusted to ⁴ Torr and 10 × 10 ⁻⁴ Torr. In other respects, fluorine-containing carbonaceous film samples A6, A7 and A8 were produced in the same manner as in the production of sample A1.

  For these samples A4 to A8, the hardness was measured in the same manner as described above. The results are shown in Table 2 together with an outline of the production conditions for each sample. This table also shows the results of sample A1 for comparison.

As can be seen from the comparison between samples A1, A4, and A5 produced by depositing the raw material gas in the atmosphere gas prepared without intentionally adding H ₂ O, the shot interval in order to increase the film formation rate The film hardness tends to decrease when the length is shortened (the shot frequency is increased). In particular, the film hardness is remarkably lowered in the sample A5 in which the shot interval is 16 Hz.

On the other hand, samples A6 to A8 in which the source gas is deposited in the atmospheric gas intentionally added with H ₂ O have the same shot interval (16 Hz) as sample A5, but have a hardness higher than that of sample A5. Greatly improved over 2.5 times. In Samples A7 and A8 in which the amount of H ₂ O added was larger, a more remarkable film hardness improvement effect was realized as compared with Sample A6. By increasing the shot frequency (frequency) in this way, the film formation rate in the production of the sample A1 was 191 nm / hour, whereas the film formation rate of the sample A7 was 913 nm / hour, and in the sample A8, 954 nm / hour. Thus, a film formation rate of 4.8 to 5.0 times that of Sample A1 was realized. Particularly in the manufacture of sample A7, a film having a hardness superior to that of sample A1 (more specifically, a hardness improved by 40% or more than that of sample A1) can be formed at a significantly higher film formation rate than that of sample A1. did it. The film formation rate is the same as the portion where the fluorine-containing carbonaceous film is formed by performing film formation with a mask tape applied to a part of the substrate in advance and peeling the mask tape after film formation. A level difference was created between the area where the substrate surface was not exposed (the area where the substrate surface was exposed), and the height of the level difference was calculated by measuring with a stylus type level gauge or roughness meter.

When XPS (X-ray Photoelectron Spectroscopy) was performed on samples A5 and A7 and the C1s spectrum was observed, a peak indicating the presence of a C—F bond in A7 as compared to A5 (for example, the binding energy of CF ₂ and CF) The height of the peak corresponding to is clearly lower. This result supports the above-mentioned assumption that a part of F atoms is removed from the deposition surface by depositing a source gas accelerated in an atmosphere to which H ₂ O has been added (which can also function as acceleration particles). Is.

<Experimental example 3>
(Preparation of sample A9)
In the production of the sample A1, the energy per shot was changed to 1.5 J, and the number of shots was adjusted so that the total energy was 100 kJ (same as A1). Further, the distance between the electrodes 12 and 14 was changed to 24 mm. In other respects, a fluorine-containing carbonaceous film sample A9 was prepared in the same manner as in the preparation of Sample A1.

(Preparation of sample A10)
In the production of the sample A1, after the air in the chamber 3 was discharged, water vapor was supplied into the chamber 3 to adjust the atmospheric gas pressure to 9 × 10 ⁻⁴ Torr. In addition, the energy per shot was changed to 1.8 J, and the number of shots was adjusted so that the total energy was 100 kJ. Furthermore, the shot interval was changed to 16 Hz.
In other respects, a fluorine-containing carbonaceous film sample A10 was prepared in the same manner as in the preparation of Sample A1.

  For these samples A9 and A10, the hardness was measured in the same manner as described above. The results are shown in Table 3 together with an outline of the production conditions for each sample. This table also shows the results of sample A1 for comparison.

As shown in Table 3, in Sample A9 in which the energy per shot was increased in order to increase the film formation rate, the film hardness was greatly reduced as compared with Sample A1. Thus, in the conventional method of depositing the source gas in the atmosphere gas prepared without intentionally adding H ₂ O, as can be seen from the comparison of the samples A1, A4, A5 and A9, the shot frequency The hardness of the sample obtained by either the method of increasing the film thickness or the method of increasing the energy per shot decreases, and it is impossible to achieve both the improvement of the film formation rate and the maintenance or improvement of the hardness.

On the other hand, in the sample A10 in which the source gas is deposited in the atmospheric gas intentionally added with H ₂ O, the energy per shot is 1.8 times that of A1, and the shot frequency is 4 times. Despite this, a film hardness superior to sample A1 (approximately twice) was realized. The film formation rate of Sample A10 was 1838 nm / hour, which was almost 10 times that of Sample A1. Thus, in the manufacture of sample A10, a film having a hardness that is clearly higher than that of sample A1 could be formed at a significantly higher film formation rate than that of sample A1.

<Experimental example 4>
(Preparation of sample A11)
In the production of Sample A1, the energy per shot was changed to 1.5 J, and the number of shots was adjusted so that the total energy was 100 kJ. Further, the shot interval was changed to 8 Hz, and the interval between the electrodes 12 and 14 was changed to 10 mm. Other points were the same as the preparation of Sample A1, and a fluorine-containing carbonaceous film sample A11 was prepared.

(Preparation of sample A12)
In the production of the sample A11, after the air in the chamber 3 was discharged, water vapor was supplied into the chamber 3 to adjust the atmospheric gas pressure to 5.0 × 10 ⁻⁴ Torr. In other respects, a fluorine-containing carbonaceous film sample A12 was prepared in the same manner as in the preparation of Sample A11.

  For these samples A11 and A12, the hardness was measured in the same manner as described above. The results are shown in Table 4 together with an outline of the production conditions for each sample.

In this experimental example, compared to the sample A11 was prepared by depositing a raw material gas in an atmospheric gas that has been prepared without the intentional addition of H 2 _O, atmospheric gas intentionally added of H 2 _O In Sample A12 in which the source gas was deposited, it was confirmed that the film hardness was significantly improved (about twice).

The Raman spectra of samples A11 and A12 were measured. The obtained spectrum is shown in FIG. 3 for sample A11 and in FIG. 4 for sample A12. As can be seen from these figures, in each of the samples A11 and A12, a spectrum in which the D peak and the G peak are superimposed (a Raman spectrum characteristic of DLC) was observed. This spectrum was decomposed into a D peak and a G peak, and the intensity of the D peak (ID) and the intensity of the G peak (IG) were calculated by subtracting the intensity of the background. The background (dotted line in FIG. 3, 4), the inclination of the flat portion of the Raman spectra near the Raman shift ^{1600cm -1 ~1800cm} -1 was determined by extrapolation. Then, the background intensity at the intermediate position (Raman shift) between the position of the D peak and the position of the G peak is IB (see FIGS. 3 and 4), and the value of IG / IB is calculated. In 3), IG / IB = 1.53, and in sample A12 (FIG. 4), IG / IB = 2.26. When the proportion of sp ³ bonds contained in the DLC film increases, the value of IG / IB increases and the film hardness tends to increase. Therefore, the value of IG / IB coincides with the fact that sample A12 has higher hardness than sample A11. Further, since the proportion of sp ³ bonds tends to decrease as the amount of fluorine contained in the DLC film increases, the value of IG / IB is determined by depositing an accelerated source gas in an atmosphere added with H ₂ O. This confirms the above assumption that a part of F atoms is removed from the deposition surface.

<Experimental example 5>
(Preparation of sample B1)
A CF material was manufactured by processing the surface of the material 70 (PTFE was used here) using the CF material manufacturing apparatus 2 having the configuration shown in FIG. The distance h3 between the electrodes 72 and 74 was 35 mm. After the atmospheric pressure in the chamber 4 is reduced to an internal pressure of 5 Pa (approximately 3.8 × 10 ⁻² Torr) or less by operating the vacuum pump 36 connected to the chamber and discharging the air in the chamber 4 The gas substantially consisting of H ₂ O was supplied to the chamber 4 to adjust the internal pressure of the chamber 4 to 12 to 13 Pa (about 0.1 Torr). By applying an electric power of 30 W to the RF power source 76 and applying an RF bias between the electrodes 72 and 74, at least a part of H ₂ O in the atmospheric gas was turned into plasma. The plasma gas particles (water plasma) were accelerated toward the electrode 72 (that is, toward the surface of the material 70), and the particles collided with the surface of the material 70 to be ion bombarded. The RF bias application time (processing time) was 15 seconds. In this way, a CF material sample B1 (surface-treated PTFE) was produced.

(Preparation of sample B2)
In the production of the sample A1, the gas supplied after the air in the chamber 4 was discharged was changed to dry argon gas. Thereby, the inside of the chamber 4 was adjusted to an atmosphere gas (total pressure: 12 to 13 Pa) environment containing approximately 5 Pa of H ₂ O gas in argon gas. In other respects, a CF material sample B2 was produced in the same manner as in the production of sample B1.

(Preparation of sample B3)
In the apparatus 2 shown in FIG. 5, the material 70 to be processed is disposed not on the electrode 72 but on the electrode 74. With this arrangement change, the acceleration direction of the water plasma with respect to the material 70 to be processed is opposite to that at the time of creating the sample B1 (the direction away from the surface of the material 70). As a result, the ion bombardment applied to the surface of the material to be processed 70 was significantly weakened compared to the sample B1. In other respects, a CF material sample B3 was produced in the same manner as in the production of sample B1.

The IR spectra of the surfaces of the samples B1 to B3 thus obtained were measured. As a control, the IR spectrum of the surface of PTFE (sample B0) before the above treatment was measured. Those IR spectra are shown in FIG. 6 by enlarging the wave number region in which absorption specific to PTFE is observed. As can be seen from this figure, in the sample B1 manufactured by colliding the plasma accelerated toward the surface of the material 70 to be processed in the atmospheric gas to which H ₂ O has been added, the sample B1 is caused by C—F bonding. The absorption is significantly weaker than that of sample B0. This spectrum data supports that the C—F bond on the surface of the material to be treated is effectively cut by the surface treatment and F atoms are removed from the surface. On the other hand, sample B2 treated in an atmospheric gas with a partial pressure of H ₂ O of less than 50% had less treatment effect (for example, F atom removal effect) than sample B1. In sample B3 in which the plasma acceleration direction was away from the substrate surface, the processing effect was further reduced.

1, 2: CF material manufacturing equipment 3, 4: Vacuum chamber (chamber)
10: Discharge means 12, 14: Electrode (raw material holder)
15: Igniter power supply 16: Igniter 17: High-voltage pulse generation source 18: Limiting resistor 20: Voltage application means 22: Capacitor 24: DC power supply 30: Atmospheric adjustment means 32: H ₂ O supply unit 322: H ₂ O tank 324: H ₂ O gas generation section 326: H ₂ O supply pipe 34: gas discharge pipe 36: vacuum pump 50: source gas source (solid resin material)
60: Substrate (base material)
62: Base material holder 70: Material to be treated 72, 74: Electrode 76: High frequency power source

Claims (7)

A method for producing a carbon material containing fluorine,
The following steps:
(A) A step of depositing a source gas containing fluorine and carbon on a substrate from a gas phase to form a deposit containing fluorine and carbon, wherein at least a part of the period in which the source gas is deposited Then, in a predetermined atmosphere gas, the source gas is deposited while colliding gas particles accelerated toward the substrate against the deposition surface; and
(B) A step of subjecting the surface of a material to be treated containing fluorine and carbon to a collision with gas particles accelerated toward the surface in a predetermined atmosphere gas;
Including at least one of
Here, the predetermined atmospheric gas has the following conditions:
(1) an atmospheric gas prepared by adding H ₂ O; and
(2) an atmospheric gas mainly composed of H ₂ O;
A method for producing a fluorine-containing carbon material, which is a gas satisfying at least one of the above. _2. The method according to claim 1, wherein the predetermined atmospheric gas is prepared by reducing the pressure in the chamber used in the step (A) or the step (B) and then supplying H ₂ O into the chamber. .   The method according to claim 1 or 2, wherein the accelerated gas particles are those obtained by accelerating charged particles by electromagnetic force.   The method according to any one of claims 1 to 3, wherein the source gas in the step (A) is obtained by sublimating a solid organic material containing fluorine.   The source gas in the step (A) is obtained by forming plasma from the material by applying discharge energy to a solid organic material containing fluorine. The method described in 1.   The method according to any one of claims 1 to 5, wherein the deposit in the step (A) is a diamond-like carbon film.   The method according to claim 1, wherein the fluorine content on the surface of the material to be treated is reduced by the step (B).

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