JP4807290B2 - Film forming method and film forming member - Google Patents

Description

  The present invention relates to a film forming method on a surface of a substrate and a film forming member having a film formed on the surface of the substrate, and relates to a film forming method having excellent adhesion and a film forming member.

  Conventionally, a film is sometimes formed on the surface of a member in order to improve the wear resistance of the member and reduce the friction coefficient. In recent years, an amorphous carbon film (so-called DLC film) has attracted attention as such a film because it has both the characteristics of being harder than other materials and the characteristic of acting as solid lubrication. ing.

  The amorphous carbon film is generally formed by arc ion plating (hereinafter referred to as AIP) or sputtering. However, the non-disappearing carbon film sometimes accumulates compressive residual stress in the film formation, has low adhesion to the base material, and in some cases, the film may peel from the base material.

  In order to solve such problems, a film that serves as an intermediate layer for improving the adhesion between the film and the substrate may be formed between the amorphous carbon film and the substrate. . As the material of the coating film serving as the intermediate layer, a metal material that easily forms a carbide with carbon between the base material and the base material is often selected. For example, a sliding member has been proposed in which a chromium layer, a chromium gradient layer, a DLC hardness gradient layer, and a hard DLC layer are formed in this order on the surface of a substrate as the intermediate layer (see, for example, Patent Document 1).

  Since such a sliding member can improve the wear resistance of the sliding member and reduce the friction coefficient by forming a DLC film on the surface, it has a layer containing chromium as an intermediate layer. Adhesion between the substrate and the film can be ensured.

JP 2004-10923 A

  However, even in the case where the intermediate layer is formed, in an environment such as high surface pressure sliding, the level of adhesion with the base material is low, and there are many phenomena of peeling due to durability evaluation and the like. ing. Further, the form of peeling of the film includes peeling between the base material and the intermediate layer and peeling between the intermediate layer and the amorphous carbon film, and it is necessary to suppress both of these peelings.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to ensure adhesion with a substrate and also ensure adhesion with an amorphous carbon film, An object of the present invention is to provide a film forming method and a film forming member on which the film is formed.

  In order to solve the above-mentioned problems, the inventors have conducted intensive studies, and as a result, it has been found that these forms of peeling are caused by the method for forming the intermediate layer and the amorphous carbon film. The inventor considered that it is important to satisfy the following two requirements for the film acting as the intermediate layer in order to eliminate the peeling of the two forms. First, in order to prevent peeling between the base material and the intermediate layer, the first requirement is to form a film that acts as the intermediate layer so as to have a throwing action on the base material. The second requirement is to further improve the wettability of the film acting as the intermediate layer with respect to the amorphous carbon film in order to prevent peeling between the intermediate layer and the amorphous carbon film. And the new knowledge that the film-forming method by AIP is effective as a film-forming method which satisfy | fills said two requirements was acquired.

  The present invention is based on the above-mentioned new knowledge of the inventor, and the film forming method according to the present invention is such that the metal of the metal target is ionized by arc discharge and a bias voltage is applied to the substrate. A method of forming a film comprising at least a step of depositing the ionized metal on the surface of the base material to form a film made of the metal, wherein in the film forming step of the metal film, The magnitude of the bias voltage at the start of the film is set to at least 500 V, the magnitude of the bias voltage at the end of the film formation is set to at least 100 V, and the bias voltage is measured from the start of the film formation to the end of the film formation. The metal film is formed while the size of the film is gradually decreased.

  According to the present invention, a metal film is formed by arc-type ion plating so that the magnitude of the bias voltage at the start of film formation is at least 500 V or more, whereby the metal ions of the metal target are interfaced (of the substrate). Since the kinetic energy is applied to the metal ions (the energy for causing the metal ions to collide with the surface of the base material is increased), the metal film can provide an anchoring effect on the base material. As a result, it becomes possible to improve the adhesion between the metal film and the substrate. In addition, the crystal structure of the metal film on the surface of the base material and in the vicinity thereof (sites in contact with the base material and in the vicinity of the film thickness direction) extends in a direction perpendicular to the surface of the base material. A columnar crystal structure (columnar structure in which the axis is perpendicular to the surface of the substrate). Furthermore, such an ion bombardment of metal ions can remove the oxide film on the surface of the substrate and activate the surface. In addition, when the magnitude of the bias voltage at the start of the film formation is less than 500 V, the anchoring effect cannot be obtained, and the substrate and the film are easily peeled off. The upper limit value of the bias voltage is not more than a value (1000 V) at which a film can be formed.

  Furthermore, in the film forming method according to the present invention, by setting the magnitude of the bias voltage at the end of the film formation to at least 100 V or less, the surface of the metal film and its vicinity are parallel to the substrate surface. It has a columnar crystal structure extending in the direction (a columnar structure in which the axis is parallel to the surface of the substrate), and the wettability of the surface of the metal film can be improved. As a result, even when a film (for example, an amorphous carbon film) is further formed on the surface of the metal film, the adhesion with the metal film can be improved. In addition, when the magnitude of the bias voltage at the end of the film formation exceeds 100 V, the wettability decreases, and the metal film and the further film covering the surface are easily peeled off.

  Further, since the metal film is formed while decreasing the magnitude of the bias voltage from the start of the film formation to the end of the film formation, the portion in contact with the surface of the base material and its portion In the vicinity, the columnar crystal structure extends in a direction perpendicular to the surface of the base material, and moves toward the surface along the thickness direction (film thickness direction) of the metal film. As a result, the axis of the columnar structure is inclined, and the columnar crystal structure extends in a direction parallel to the surface of the base material at and near the surface of the metal film. As a result, the strength of the metal is stabilized. Note that examples of a method of decreasing the bias voltage in an inclined manner include a method of decreasing the bias voltage by continuously inclining, and a method of decreasing the bias voltage by inclining in steps.

  The film forming method according to the present invention further includes a step of forming an amorphous carbon film containing the metal of the metal target on the surface of the metal film, and the metal target includes a group 4A element, The metal film is formed using one or more metal targets selected from Group 5A elements, Group 6A elements, Group 3B elements, and Si, and the amorphous carbon film is formed using the metal target. In a state where a hydrocarbon gas is further supplied between the base metal and the base material, the target metal and the hydrocarbon gas hydrocarbon are ionized and a bias voltage is applied to the base material. preferable.

  According to the present invention, since the metal described above has high oxide forming ability and carbide forming ability, the adhesion between the substrate and the amorphous carbon film can be improved by using a target made of such a metal. it can. Among the metals, more preferable metal elements are one or more metal elements selected from Ta, Ti, Cr, Al, Mg, W, V, Nb, and Mo. Among these, Ta, Ti Cr is particularly preferable.

  In addition, the amorphous carbon film does not use a solid carbon target, only a metal target is disposed, the metal target is sublimated by arc discharge, and the carbonization of the metal and the introduced hydrocarbon gas is ionized. Since it is formed, a metal composite amorphous carbon film can be obtained. Furthermore, in the conventional sputtering method, a solid carbon target, which is a carbon evaporation source, and a metal target, which is a metal evaporation source, are used in combination with conventional sputtering, whereas in the present invention, only a metal target is subjected to arc discharge. Is different in that ion plating (arc-type ion plating (AIP) method) is performed. Therefore, when the film is formed by the film forming method according to the present invention, the friction coefficient of the amorphous carbon film is reduced, and the metal is reduced. The adhesion with the film can be improved, the wear resistance can be improved, and the film formation time can be shortened.

  The hydrocarbon gas referred to in the present invention is preferably one or more chain hydrocarbon compounds selected from alkane compounds, alkene compounds, and alkyne compounds. Among them, 1 selected from methane, ethylene, and acetylene. More than species are preferred.

  In the film forming method according to the present invention, the metal film is more preferably formed such that the thickness of the metal film is at least 20 nm or more. By making the film 20 nm or more, adhesion between the metal film and the substrate can be ensured. That is, when the film is less than 20 nm, the film is easily peeled from the substrate. The thickness of the metal film is more preferably 100 nm or less. Even if it exceeds 100 nm, no further effect of adhesion can be expected, which is not economical.

  In the film forming method of the present invention, the ratio of carbon in the amorphous carbon film is increased by increasing the concentration of the hydrocarbon gas in the film forming step of the amorphous carbon film. More preferably, the thickness is increased in a gradient along the thickness direction toward the surface of the amorphous carbon film. According to the present invention, since the proportion of carbon element on the surface of the amorphous carbon film increases, a film excellent in wear resistance and low friction can be formed.

  Further, in addition to the method for forming the amorphous carbon film, the film forming method according to the present invention may be configured such that the bias voltage at the start of film formation of the amorphous carbon film is set to the film formation end of the metal film. More preferably, it is the same size as the bias voltage at the time. According to the present invention, by matching the bias voltage, the crystal structure of the surface of the metal film and the form of the crystal structure formed on the surface of the metal film are both parallel to the surface of the substrate. Since it is possible to form a columnar crystal structure extending in the direction, the interfaces with high wettability are in close contact with each other, so that misfit between the metal film and the amorphous carbon film is suppressed, and these adhesions are reduced. Further improvement can be achieved. Further, a film forming method for increasing the proportion of carbon in the amorphous carbon film in a gradient along the thickness direction of the amorphous carbon film, that is, a metal of a metal target in the amorphous carbon film. The composition of the metal structure at the interface is made closer by performing a film forming method in which the ratio of is increased in a gradient along the thickness direction toward the interface between the amorphous carbon film and the metal film. Can be further matched. Thereby, the adhesiveness of an amorphous carbon film and a metal film can further be improved.

  In the film forming method according to the present invention, it is more preferable to form the amorphous carbon film while increasing the magnitude of the bias voltage. According to the present invention, the compressive residual stress inside the amorphous carbon film can be relaxed, and the adhesion between the amorphous carbon film and the metal film can be secured. And the member which formed the film | membrane formed into a film by such a film-forming method on the base material is suitable as a sliding member.

  Furthermore, the suitable film formation member manufactured by the film-forming method of the film concerning the present invention is also indicated as the present invention. The film-forming member according to the present invention is a film-forming member in which at least a metal film is formed on the surface of a base material, and the metal film is formed at the contact portion with the surface of the base material and in the vicinity thereof. A columnar crystal structure extending in a direction perpendicular to the surface is formed, and a columnar crystal structure extending in a direction parallel to the substrate surface is formed at and near the surface of the metal film. It is characterized by being.

  According to the present invention, the film-forming member forms a columnar crystal structure extending in a direction perpendicular to the surface of the substrate at and near the contact portion with the surface of the substrate. The columnar crystal structure provides an anchoring action with the base material. As a result, the metal film is difficult to peel from the substrate. Further, the film forming member forms a columnar crystal structure extending in a direction parallel to the surface of the substrate at and near the surface of the metal film, and the surface on which the columnar crystal structure is formed is Improves wettability. As a result, the adhesion of the film covering the metal film surface can be improved.

  Further, in the film forming member according to the present invention, the metal of the metal film is one or more metals selected from a group 4A element, a group 5A element, a group 6A element, a group 3B element, and Si, It is preferable that an amorphous carbon film containing the metal of the metal film is further formed on the surface of the film. Since the metal shown above has high oxide forming ability and carbide forming ability, the adhesion between the base material and the amorphous carbon film can be enhanced by using a target made of such a metal.

  In the film forming member according to the present invention, the thickness of the metal film is more preferably at least 20 nm, and the amorphous carbon film is along a thickness direction toward the surface of the amorphous carbon film. Thus, it is more preferable that the proportion of carbon increases in a gradient manner.

  In the film forming member according to the present invention, the amorphous carbon film on the surface of the metal film and in the vicinity thereof preferably has a columnar crystal structure extending in a direction parallel to the substrate surface. According to the present invention, since the surfaces of a highly wettable metal film and an amorphous carbon film are in close contact with each other, the adhesion between the metal film and the amorphous carbon film can be further improved.

  According to the present invention, it is possible to increase the adhesion between the metal film and the substrate, and to improve the wettability of the surface of the metal film. Even when a film is further formed, a metal film capable of improving the adhesion between the metal film and the further film can be obtained.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic view of a film forming apparatus suitable for forming a metal film according to the present embodiment and an amorphous carbon film on the surface of the metal film, and FIG. It is a figure for demonstrating the suitable manufacturing method of an amorphous carbon membrane | film | coat. FIG. 3 is a schematic diagram of the metal structure in the cross section of the metal film according to the present embodiment.

  As shown in FIG. 1, the film forming apparatus is an apparatus for arc type ion plating (AIP), in which a plurality of metal targets are arranged in a vacuum chamber (vacuum container) exhausted by a vacuum pump. The base material on which the film is to be formed is arranged on a central rotary table so that a bias voltage can be applied to a metal target described later. On the other hand, a metal target material (cathode) and an anode are arranged in a vacuum chamber so that an arc current can be passed in order to sublimate and ionize the metal of the metal target material, which is the material of the metal film, by arc discharge. Yes. Moreover, Cr, Ti, Ta, etc. are selected as a metal target used as a cathode. On the other hand, an inert gas for discharge such as nitrogen and argon is introduced into the vacuum vessel from the nozzle and exhausted after the treatment, and hydrocarbon gas, which is a process gas other than the discharge gas, is also introduced from the nozzle. , Exhausted after processing.

  Using such an apparatus shown in FIG. 1, while supplying an inert gas for discharge to the vacuum chamber, a metal target material (conductive metal) is used as a cathode, and arc discharge is generated between the anode and the anode. With this energy, the metal of the metal target material is sublimated and ionized, and a negative bias voltage is applied to the base material to attach the ions to the base material, thereby forming a metal film. For example, in the case of a typical TiN film, the TiN film can be formed on the surface of the substrate by using Ti as the material and introducing nitrogen into the gas.

  In this embodiment, when an amorphous carbon film is further formed on the surface of the metal film, a hydrocarbon gas is further supplied between the metal target and the base material without using a carbon material as a target material. In this state, the target metal and hydrocarbon gas hydrocarbons are ionized and a bias voltage is applied to the substrate to form an amorphous carbon film.

  In this embodiment, using such an apparatus, film formation is performed on the surface of the substrate as shown in FIG. More specifically, first, the magnitude of the bias voltage applied to the substrate at the start of metal film deposition (initial stage of film deposition) is set to at least 500 V (800 V in FIG. 2), and the metal of the metal target is arced. While ionizing by discharge, the ionized metal is adhered to the surface of the base material by the bias voltage (the metal layer deposition initial stage in FIG. 2). Then, while gradually decreasing the magnitude of the bias voltage, the magnitude of the bias voltage at the end of the film formation (film formation end) is set to at least 100 V or less (50 V in FIG. 2), and the ionized metal is continued. And attach.

  Thus, as shown in FIG. 3, the surface of the base material 70 becomes a surface having a throwing effect on the complicated unevenness, and further, the surface of the base material 70 and the vicinity thereof (the part in contact with the base material and In the vicinity of the film thickness direction, a columnar crystal structure 21 having an anchoring action extending in a direction perpendicular to the surface of the substrate 70 (the axis is perpendicular to the surface of the substrate 70). A columnar structure 21) is formed. Further, on the surface of the metal film 20 and in the vicinity thereof, there is a columnar crystal structure 22 (columnar structure 22 in which the axis is parallel to the surface of the substrate 70) extending in a direction parallel to the substrate surface. Thus, the wettability of the surface of the metal film 20 can be improved.

  Further, after forming a metal film (after forming the metal layer), as shown in FIG. 2, an amorphous carbon film (metal composite DLC gradient structure) is further formed on the surface of the metal film (metal layer). Specifically, in a state where a hydrocarbon gas is further supplied between the metal target and the base material, the target metal and the hydrocarbon gas hydrocarbon are ionized by arc discharge, and the base material is An amorphous carbon film is formed by applying a bias voltage. However, the bias voltage at the start of film formation of the amorphous carbon film is the same as the bias voltage at the end of film formation of the metal film. Thus, both the crystal structure of the surface of the metal film and the form of the crystal structure of the amorphous carbon film formed on the surface of the metal film are both relative to the surface of the base material. Since a columnar crystal structure extending in the parallel direction can be formed, the interfaces with high wettability are in close contact with each other, so that the adhesion between the metal film and the amorphous carbon film can be further improved.

Further, when the amorphous carbon film is formed, the concentration of the carbon in the amorphous carbon film is reduced by increasing the concentration of the hydrocarbon-based hydrogen gas (for example, C ₂ H ₂ gas). The amorphous carbon film is formed while increasing the thickness along the thickness direction toward the surface of the crystalline carbon film and decreasing the magnitude of the bias voltage. Thus, as shown in FIG. 2, a sliding member in which a metal layer (metal film) and a layer having a metal composite DLC gradient structure (amorphous carbon film) are sequentially formed on the surface of the substrate. A suitable film forming member can be obtained.

  The amorphous carbon film thus formed can further improve the adhesion with the metal film. Furthermore, since the surface of the amorphous carbon film contains a large proportion of carbon element, the wear resistance is improved and the friction coefficient is reduced.

Examples according to this embodiment will be described below.
Example 1
<Film forming member>
The test piece shown below was created as a film forming member according to the embodiment. As a base material, a chromium molybdenum steel (JIS standard: SCM415 equivalent) having a Vickers hardness of Hv800, which has been quenched and tempered with a diameter of 28 mm and a thickness of 3 mm, was prepared. Was polished so that the center line average roughness was 0.007 μm. Then, a titanium target is prepared as a metal target, the magnitude of the bias voltage at the start of film formation (initial stage of film formation) is 800 V, the magnitude of the bias voltage at the end of film formation (end of film formation) is 50 V, From the beginning of film formation to the end of film formation, while gradually decreasing the magnitude of the bias voltage, the metal of the titanium target is ionized by arc discharge and ionized titanium is attached to the circular surface by the bias voltage. A metal film made of titanium was formed. At this stage, the surface texture observation and wettability test described later were performed.

Next, in a state where acetylene gas (C ₂ H ₂ ) gas is further supplied as a hydrocarbon gas between the titanium target and the substrate, titanium of the titanium target and hydrocarbon of hydrocarbon gas (specifically, carbon) As shown in FIG. 2, the acetylene gas is gradually increased from 0 to 300 scm, the bias voltage is increased to 50 V to 300 V at the time of film formation, and the titanium element is increased. Along with the film thickness direction toward the surface of the amorphous carbon film, the contained ratio forms a film of an amorphous carbon film in which a titanium alloy that changes in a gradient from 100% by mass to 20% by mass is combined, A test piece was produced.

<Microscope observation>
In order to observe the cross section of the film of the test piece, the test piece was cut, and the cross section was observed with a TEM (transmission electron microscope). The result is shown in FIG. Further, before the formation of the amorphous carbon film, the surface of the metal film when the film formation of the titanium metal film was completed was observed with an AFM (atomic force microscope). The result is shown in FIG.

<Wettability test>
As shown in FIG. 6, (a) pure water, (b) formamine, and (c) ethylene glycol are dropped on the surface of a substrate (solid) on which a metal film is formed, and the contact angles of these liquids are measured. From the contact angle, the size of the adhesion work was calculated as an index of surface adhesion. The result is shown in FIG.

<Adhesion test>
Test by scratch method: The adhesion of the film was measured. Specifically, using a diamond indenter with a radius of 0.2 μm, the indenter was moved relative to the thin film surface at a load speed of 100 N / min while moving the indenter at 10 mm / min. The load was measured as the adhesion of the thin film. The result is shown in FIG.

  Test by Rockwell method: HRc method (Rockwell hardness measurement method) indenter (diamond indenter with a tip radius of curvature of 0.2 mm and a cone angle of 120 °) is pushed into the coating surface with a load of 150 kg. The adhesion (peelability) of the film was confirmed. The result is shown in FIG.

<Friction and wear test>
Using the ball-on-disk test apparatus shown in FIG. Specifically, the test piece on which the film was formed was rotated at a rotation speed of 500 rpm, and a high carbon chromium bearing steel (JIS standard: SUJ2) having a diameter of 6.35 mm was pressed at 10 N to measure the rotational resistance of the test piece. Thus, the friction coefficient was calculated, the wear depth of the film was measured, and the wear depth was defined as the wear amount. The result is shown in FIG.

(Comparative Example 1)
The same base material as Example 1 was prepared. The difference from Example 1 is that a metal film and an amorphous carbon film are formed by sputtering, and the furnace pressure is 0.3 Pa between the base material and the titanium target made of titanium. In this state, the film forming temperature (specifically, the temperature of the substrate) is maintained at 150 ° C., and the bias is adjusted to 800 V between the titanium target and the substrate. While applying voltage, plasma was generated and the surface of the substrate was sputtered to form a metal film. Furthermore, a titanium target and a carbon target are prepared, and under the above conditions, a titanium-carbon composite layer in which the proportion of titanium decreases along the thickness direction is formed. Further, an amorphous carbon film (Ti composite) in which titanium is composited is formed. DLC layer) was formed. Then, under the same conditions as in Example 1, a microscopic observation, an adhesion test, and a friction test were performed. The results are shown in FIG. 4 (b), FIG. 5 (b), and FIG.

(Comparative Example 2)
In the same manner as in Example 1, a film was formed by the AIP method. The difference from the first embodiment is that the magnitude of the bias voltage at the time of forming the metal film is constant at 800V. Then, as in Example 1, microscopic observation and wettability test were performed. The results are shown in FIG. 5 (c) and FIG.

(Result 1: Microscopic observation)
From FIG. 4A, the base material of Example 1 and the titanium layer (Ti layer) which is a metal layer (metal film) are intricate uneven surfaces. Further, the metal layer has a columnar metal crystal having a width of 40 nm to 50 nm and a length of 200 mm to 400 nm extending in a direction perpendicular to the surface of the base material at and near the portion in contact with the surface of the base material. Was formed. Furthermore, as shown to Fig.5 (a), in the surface of the metal membrane | film | coat (metal layer) of Example 1, and its vicinity, width 40nm-50nm extended in the parallel direction with respect to the base-material surface, length 200mm- A columnar crystal structure of 400 nm was formed.

  The metal layer in contact with the surface of the base material of Comparative Example 1 and the vicinity thereof, and further, the surface of the metal layer (metal film) and the vicinity thereof have columnar shapes extending in a direction parallel to the base material surface. A columnar crystal structure having a crystal structure was confirmed.

  Further, a columnar crystal structure extending in a direction perpendicular to the surface of the base material at and near the portion in contact with the surface of the base material of Comparative Example 2 and the surface of the metal layer (metal film) and the vicinity thereof. A columnar crystal structure having In addition, as for the surface roughness of Example 1 and Comparative Examples 1 and 2, the center line average roughness Ra was about 1.0 nm.

(Result 2: wettability test)
As shown in FIG. 6, the adhesion work on the surface of the metal film of Example 1 was larger than that of Comparative Example 2 regardless of which liquid was used.

(Result 3: Adhesion test)
As shown in FIG. 7, in Example 1, the load by the scratch method was as high as 40 N compared to Comparative Example 1 (Comparative Example 1 was 20 N), and in the HRc method, only the film of Comparative Example 1 was peeled off. From this result, it was found that the film of Example 1 was superior in adhesion.

(Result 4: Friction and wear test)
The friction coefficients of Example 1 and Comparative Example 1 were comparable, and the wear amount of Example 1 was smaller than that of Comparative Example 1. The film formation time of the film of Example 1 was about 4 times shorter than that of Comparative Example 1.

(Discussion)
As a result, the base material and the metal layer of Example 1 have an intricate uneven surface at the interface, and the metal layer portion in contact with the surface of the base material and the vicinity thereof are on the base material surface. On the other hand, it is considered that the anchoring effect was obtained between the base material and the metal layer by forming the columnar metal crystal extending in the vertical direction. Thereby, as shown in the result 3, it is considered that the adhesiveness of the film in Example 1 was higher than that in Comparative Example 1. In the initial stage of film formation in Example 1, Ti atoms are ionized by AIP, and the bias voltage is larger than the bias voltage at the time of general film formation, so the force to attract atoms is strong. As a result, the energy when colliding with the base material is large, so that the interface between the base material and the metal layer becomes an uneven surface, and columnar metal crystals extending in the direction perpendicular to the base material surface are formed. It is estimated to be.

  Further, from the result 1, the surface of the metal film (metal layer) of Example 1 and the vicinity thereof have a columnar crystal structure extending in a direction parallel to the substrate surface, and such a crystal structure The surface made of is considered to have a large adhesion work and high wettability. On the other hand, the metal film of Comparative Example 2 has a columnar crystal structure extending in the direction perpendicular to the substrate surface along the film thickness direction. It is thought that the size of work is small and the wettability is also low. Due to such characteristics, it is considered that the adhesiveness between the metal film (metal layer) and the amorphous carbon film is higher in Example 1 than in Comparative Example 2. At the end of film formation in Example 1, Ti atoms are ionized by AIP, but the bias voltage is small, so the force for attracting atoms is weak. Thereby, since the energy at the time of colliding with a base material is small, it is estimated that the columnar metal crystal extended in the parallel direction with respect to the base-material surface was formed.

(Examples 2 and 3)
In the same manner as in Example 1, a metal layer (metal film) and a metal composite DLC layer (amorphous carbon film) were formed on the surface of the substrate. The difference from Example 1 is that the magnitude of the bias voltage at the start (initial stage) of the metal film is 500V. In Example 3, the film was formed under the same conditions as in Example 2. And with respect to the film | membrane of Example 2, 3, 100 kg and 150 kg of load were added by the HRc method among the adhesiveness tests of Example 1, and peeling of the film | membrane was confirmed. The results are shown in Table 1.

(Comparative Examples 3 and 4)
In the same manner as in Example 1, a metal layer (metal film) and a metal composite DLC layer (amorphous carbon film) were formed on the surface of the substrate. Comparative Example 3 is different from Example 1 in that the magnitude of the bias voltage at the start (initial stage) of forming the metal film is 250V. Comparative Example 4 differs from Example 1 in that the magnitude of the bias voltage at the start of metal film deposition (initial stage) was 250 V, and the proportion of titanium along the thickness direction was 20 mass. %, The amorphous carbon film was formed. And the adhesion test similar to Example 2 was done with respect to the film of Comparative Examples 2 and 3. The results are shown in Table 1.

(Result 5 and discussion)
Although the films of Examples 2 and 3 did not peel, the films of Comparative Examples 3 and 4 peeled from the interface between the base material and the metal film. From these results, in Examples 2 and 3, the bias voltage at the start of deposition of the metal film (initial) was larger than that in Comparative Examples 3 and 4, and thus the above-described casting was performed at the interface between the base material and the metal film. As a result, it is considered that the films of Examples 2 and 3 did not peel off. From this, in order to obtain the throwing effect, as in Examples 2 and 3, the magnitude of the bias voltage at the start (initial) of the metal film formation needs to be at least 500 V or more. Moreover, it is thought that even if it changes a metal composition ratio like the comparative example 4, it has little influence on the adhesiveness in the interface of a base material and a metal film.

(Examples 4 to 6)
In the same manner as in Example 2, a metal layer (metal film) and a metal composite DLC layer (amorphous carbon film) were formed on the surface of the substrate. Examples 4 to 6 differ from Example 2 in that the magnitude of the bias voltage at the end of film formation (final stage) was set to 25 V, 50 V, and 100 V in order, and the amorphous carbon film That is, the magnitude of the bias voltage at the start of film formation (initial) is set to 25 V, 50 V, and 100 V in sequence. Example 6 is further different from Example 2 in that the amorphous carbon film is formed with the proportion of titanium along the thickness direction being constant at 20% by mass. And the adhesiveness test similar to Example 2 was done with respect to the film | membrane of Examples 4-6. The results are shown in Table 2.

(Comparative Example 5)
In the same manner as in Example 4, a metal layer (metal film) and a metal composite DLC layer (amorphous carbon film) were formed on the surface of the substrate. The comparative example 4 is different from the example 4 in that the magnitude of the bias voltage at the end of the metal film formation (end) is 500V. And the adhesion test similar to Example 4 was done with respect to the film of Comparative Example 5. The results are shown in Table 2.

(Result 6 and discussion)
Although the films of Examples 4 to 6 did not peel, the film of Comparative Example 5 peeled from the interface between the metal film and the amorphous carbon film. From these results, in Examples 4 to 6, the bias voltage at the end of film formation (terminal) of the metal film was smaller than those in Comparative Examples 3 and 4, thereby improving the wettability of the surface of the metal film. It is considered that the adhesion between the metal film and the amorphous carbon film is improved. For these reasons, it is considered that the films of Examples 4 to 6 did not peel off. From this, in order to obtain the wettability, as in Examples 4 to 6, the magnitude of the bias voltage at the end of film formation (final stage) needs to be 100 V or less. In addition, as in Example 6, even if the metal composition ratio is changed, it is considered that the influence on the adhesion between the metal film and the amorphous carbon film is small.

(Examples 7 and 8)
In the same manner as in Example 2, a metal layer (metal film) and a metal composite DLC layer (amorphous carbon film) were formed on the surface of the substrate. The film forming conditions of Example 7 are the same as those of Example 2, and Example 8 is different from Example 2 in that the thickness of the metal film is 50 nm. And the adhesion test similar to Example 2 was done with respect to the films of Examples 7 and 8. The results are shown in Table 2.

(Comparative Examples 6-9)
In the same manner as in Example 7, a metal layer (metal film) and a metal composite DLC layer (amorphous carbon film) were formed on the surface of the substrate. Comparative Example 6-9 differs from Example 7 in that the thickness of the metal film is 5 nm. The comparative example 7 is further different in that the magnitude of the bias voltage at the start of film formation of the amorphous carbon film (initial stage) is 300V. The comparative example 8 is different in that the magnitude of the bias voltage at the start (initial stage) of forming the metal film is 250V. In Comparative Example 9, the magnitude of the bias voltage at the start of metal film deposition (initial) was 250 V, and the magnitude of the bias voltage at the start of amorphous carbon film deposition (initial). Is different from that of 300V. And the test similar to Example 4 was done. The results are shown in Table 3.

(Result 7 and discussion)
Although the films of Examples 7 and 8 did not peel, the films of Comparative Examples 6 to 9 peeled from the interface between the base material and the metal film. However, the film of Comparative Example 6 was not peeled at 100 kg depending on the measurement location. In Comparative Examples 7 and 9, there were also those that peeled off from the interface between the metal film and the amorphous carbon film. From these results, it is considered that in Examples 7 and 8, the film thickness was larger than those in Comparative Examples 6 to 9, and thus the adhesion between the base material and the metal film was surely improved. For these reasons, it is considered that the films of Examples 7 and 8 did not peel off. From this, it is considered that the film thickness is preferably 20 nm or more as in Examples 7 and 8. In addition, as in Comparative Examples 7 and 9, some peeled from the interface between the metal film and the amorphous carbon film because of the large bias voltage at the start of the film formation of the amorphous carbon film (initial). Since the bias voltage was larger than the bias voltage at the end of the metal film deposition (final stage), a crystal structure different from the structure of the metal film interface with high wettability appeared at the interface of the amorphous carbon film. It is considered that the adhesion between the interfaces was lowered.

1 is a schematic view of a film forming apparatus suitable for forming a metal film according to the present embodiment and an amorphous carbon film on the surface of the metal film. The figure for demonstrating the suitable manufacturing method of the metal membrane | film | coat and amorphous carbon membrane which concern on this embodiment. The schematic diagram of the metal structure in the cross section of the metal film which concerns on this embodiment. The photograph figure observed from TEM (transmission electron microscope) of Example 1 and Comparative Example 1. FIG. The photograph figure which observed the metal film surface of Example 1 and Comparative Examples 1 and 2 with AFM (atomic force microscope). The figure which showed the result of the wettability test of Example 1 and Comparative Example 2. The figure which showed the result of the adhesiveness test of Example 1 and the comparative example 1, and the friction abrasion test. The figure for demonstrating a friction abrasion test.

Explanation of symbols

20: Metal film, 21: Columnar crystal structure extending in a direction perpendicular to the surface of the base material, 22: Columnar crystal structure extending in a direction parallel to the surface of the base material, 70: Base material

Claims (11)

At least a step of ionizing the metal of the metal target by arc discharge and applying a bias voltage to the base material to attach the ionized metal to the surface of the base material to form a film made of the metal. A method of forming a coating film including:
In the metal film formation step, the magnitude of the bias voltage at the start of the film formation is at least 500 V or more, the magnitude of the bias voltage at the end of the film formation is at least 100 V or less, and the film formation is started. the layers up to end, have rows deposition of the metal coating while inclined to reduce the magnitude of the bias voltage from,
A method of forming a film, further comprising the step of forming an amorphous carbon film containing the metal of the metal target on the surface of the metal film . As before Symbol metal target, perform deposition of the metal coating with 4A group element, 5A group elements, 6A Group elements, 3B group elements, and at least one metal target is selected from Si,
The amorphous carbon film is formed by ionizing the metal of the target and the hydrocarbon gas in a state where a hydrocarbon gas is further supplied between the metal target and the base material, and The method for forming a film according to claim 1, wherein the method is performed by applying a bias voltage to the substrate.   The film forming method according to claim 2, wherein the metal film is formed so that the thickness of the metal film is at least 20 nm or more.   In the film forming step of the amorphous carbon film, by increasing the concentration of the hydrocarbon-based hydrogen gas, the ratio of carbon in the amorphous carbon film is increased in the thickness direction toward the surface of the amorphous carbon film. The method of forming a film according to claim 1, wherein the film is increased in a slanting manner along the line.   5. The film forming method according to claim 1, wherein the amorphous carbon film is formed while increasing the magnitude of the bias voltage. 6. The method of forming a film according to claim 5, wherein a bias voltage at the start of film formation of the amorphous carbon film is the same as a bias voltage at the end of film formation of the metal film. The sliding member which formed the film | membrane formed into a film by the film-forming method in any one of Claims 1-6 on the surface of the base material. A film forming member having at least a metal film formed on the surface of a substrate,
The metal film forms a columnar crystal structure extending in a direction perpendicular to the surface of the base material at and near the contact portion with the surface of the base material,
At the surface of the metal film and in the vicinity thereof, a columnar crystal structure extending in a direction parallel to the substrate surface is formed ,
A film-forming member , wherein an amorphous carbon film containing the metal of the metal film is further formed on the surface of the metal film . Metal of the metal coating, 4A group elements, 5A Group elements, 6A Group elements, 3B group elements, and film forming member according to claim 8, characterized in that the Si is one or more metals selected . The film forming member according to claim 8 or 9 , wherein the thickness of the metal film is at least 20 nm or more. The amorphous carbon film along the thickness direction toward the surface of the amorphous carbon film, inclined manner according to claim 8, characterized in that the proportion of carbon is increased Film forming member.

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