JPH06306619A - Coating film forming device - Google Patents

Abstract

PURPOSE:To form a coating film having high adhesion on a wide range of materials to be coated by specifying the relation of the diameters of the ion beam draw-out holes with the interval between draw-out grid electrodes. CONSTITUTION:The set of grid electrodes 4 consisting of the plural grid electrodes 5 to 7 arranged so as to be superposed on each other is placed between the treating chamber 1 and the vacuum plasma chamber 2. Then the ion beam draw-out voltage is applied between the grid electrodes 5 and 7 from the power source 8 and the suppressor voltage is applied between the grid electrodes 6 and 7 from the power source 9. Each of the grid electrodes 5 to 7 is provided with one hole at the center and plural holes at the circumference. At this time, the ratio (p/d, aspect ratio) of the diameter of the hole at the center (p) and the distance (d) between the adjacent two grid electrodes is set at <=1 and the ratio (p/d) of the diameter of the holes on the outer circumference (p) and the distance (d) between the adjacent two grid electrodes is set at >1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus for forming a film having excellent adhesion.

[0002]

2. Description of the Related Art Generally, when a member is made highly functional by coating the surface with a film, it is required that the material to be treated as an underlayer and the film have excellent adhesion. Therefore, in industrial use, various methods have been conventionally applied to the pretreatment of the material to be treated, the process conditions and the like by a wet process such as plating or a dry process such as vapor deposition.

The problem of the adhesion between the material to be treated and the film is
It is also greatly affected by the combination of both. For example, taking a carbon film, particularly a film having a structure of diamond and diamond-like carbon as an example, a technique capable of obtaining a certain degree of adhesion when the material to be treated is a silicon-based material has been realized in CVD or the like. However, if the material to be treated is a cemented carbide such as tungsten carbide, its adhesion is poor,
Furthermore, practically good adhesion has not been obtained for iron-based materials.

As a method for solving the problem that the adhesion is poor depending on the type of the material to be treated, it is conceivable to modify the surface of the material to be treated to a material having good adhesion to the film to be formed. . Taking diamonds and diamond-like carbon coatings as examples again, proposals have been made to obtain high adhesion with various materials to be treated based on this idea. For example, Japanese Patent Application Laid-Open No. 62-10300 proposes a member having an improved adhesion by sandwiching an intermediate layer of a metal and its carbide or nitride between a material to be treated and a carbon film. However, the above-mentioned method has many demerits such that there is room for further improvement in the adhesion between the intermediate layer and the film, and the number of steps for forming the intermediate layer increases.

On the other hand, Japanese Unexamined Patent Publication (Kokai) No. 58-153774 discloses a method of simultaneously using film formation and ion implantation, and Japanese Unexamined Patent Publication (Kokai) No. 59-93348 discloses a method of ion beam evaporation and ion implantation. A method that uses the injection method in combination is disclosed in Japanese Patent Application Laid-Open No. Hei 2
No. 250967 discloses a material of the periodic table IVa.
Methods of implanting Group III, Va or VIa elements to further coat the film are disclosed.

However, in all of these methods using ion beams, the film forming apparatus and the ion beam generating apparatus are different from each other, so that the apparatus as a whole becomes large and the initial capital investment and running cost increase. As a result, although some improvement in adhesion can be obtained, the manufacturing cost is increased.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and its main purpose is to perform film formation and ion beam generation by one apparatus. Accordingly, it is an object of the present invention to provide a film forming apparatus capable of forming a film having high adhesion to a wide variety of materials to be processed without increasing the manufacturing cost.

[0008]

According to the present invention, the above object is to provide a vacuum arc discharge electrode for melting and evaporating a film forming material so as to form a film on the surface of a substrate held in a processing chamber. A vacuum plasma chamber for confining the plasma generated by the discharge, a hole provided so as to overlap between the vacuum plasma chamber and the processing chamber, and a hole for taking out the plasma into the processing chamber. In a film forming apparatus having a set of grid electrodes composed of a plurality of grid electrodes and a power supply for applying a voltage to each of the electrodes, the set of grid electrodes includes a hole diameter p and a space between the grid electrodes. It is achieved by providing a film forming apparatus characterized by having a first hole having a ratio p / d with respect to the distance d of more than 1 and a second hole having the ratio p / d of not more than 1. It

It is needless to say that the plasma described here may contain, in addition to ions, electrons, and neutral atoms, molten particles of a cathode material which is generally known to be generated in a vacuum arc discharge. Absent.

[0010]

The vacuum arc discharge ionizes the constituent atoms of the cathode material evaporated in a portion called a cathode spot near the cathode to form plasma. Ions that generate an ion beam by exposing the material to be treated directly to this plasma as a medium for film formation or by arranging a set of grid electrodes applied with a negative voltage to the plasma in close contact with the plasma It has been used as a source plasma.

However, although the vacuum arc ion source technique and the arc film forming technique use the same plasma generation method called vacuum arc discharge, they have been developed as mutually different techniques. That is, in the vacuum arc film forming apparatus shown in FIG. 3, in order to cause the generated plasma itself to act on the surface of the material 11 to be processed, plasma is generated with the electrode 22 inside the processing chamber 21 and the material to be processed is exposed therein. This is a film forming technology that is included in the range of vacuum vapor deposition and ion plating because of its structure. Also, as shown in FIG.
The vacuum arc ion source device includes a processing chamber 31 for the material 11 to be processed.
And a vacuum plasma chamber 32 in which a vacuum arc discharge electrode 33 is provided to generate vacuum arc plasma, and a plurality of vacuum plasma chambers 32 are provided between the processing chamber 31 and the vacuum plasma chamber 32 so as to overlap each other. A grid electrode set 34 composed of grid electrodes is arranged, and a beam extraction voltage and a suppressor voltage are applied by power sources 38 and 39. In such a vacuum arc ion source device, in order to confine the generated plasma in the space inside the ion source to operate, the material to be processed is processed in a state in which the processing chamber and the plasma reaction chamber are separated. These technologies had different ideas.

In the film forming apparatus according to the present invention, a hole for contacting vacuum arc plasma to take out plasma is provided in a set of ion beam extraction grid electrodes, and a vacuum arc medium such as internal plasma is ejected through this hole and introduced into the processing chamber. Then, the material to be treated is irradiated. Here, the ion beam extraction hole having an aspect ratio of 1 or less and the plasma extraction hole having an aspect ratio of more than 1 coexist in the grid electrode in contact with the plasma, so that the plasma generated by the apparatus and the ion beam are generated in the material to be treated. And are simultaneously irradiated to form a film. However, although the ion beam extraction is performed to some extent from the hole for taking out the plasma, the plasma ejection hole may also have the function of the ion beam extraction hole.

Usually, when operating an ion source for extracting an ion beam from plasma, p / d is called an aspect ratio, where p is the diameter of the ion beam extraction hole and d is the distance between the extraction grid electrodes. Since the ion beam current that can be extracted from this ion beam extraction hole increases in proportion to the square of the aspect ratio, it is desirable to design an ion beam extraction structure having a maximum aspect ratio while maintaining a good plasma state. However, taking a large aspect ratio means that the hole diameter becomes large with respect to the electrode interval.If the aspect ratio is too large, the potential difference between the edge of the hole and the central portion increases, and good ion beam extraction can be performed. In order to eliminate it, the aspect ratio is usually designed to be 1 or less. On the other hand, in the device of the present invention, in order to take out plasma, a hole having an aspect ratio of more than 1 is provided so that the plasma is ejected from this hole, the structure is simplified, the device cost is reduced, and the reliability is improved. In addition, it is possible to obtain a film with higher adhesion.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

The vacuum arc film forming apparatus of the present invention comprises a processing chamber 1 for forming a carbon film 12 on the surface of a substrate 11 as a material to be processed, and a vacuum plasma chamber 2 for generating a vacuum arc plasma. Have Vacuum plasma chamber 2
Is provided with a vacuum arc discharge electrode 3. Further, between the processing chamber 1 and the vacuum plasma chamber 2, a grid electrode set 4 including a plurality of grid electrodes 5 to 7 provided so as to overlap each other is provided. This grid electrode 5
The beam extraction voltage is applied between the grid electrode 7 and the grid electrode 7 by the power supply 8, and the suppressor voltage is applied between the grid electrode 6 and the grid electrode 7 by the power supply 9. There is.

Each grid electrode 5 of the grid electrode set 4
In FIG. 7, as shown in FIG. 2 (a), one first hole 4 a is provided at the center, six holes are provided on the circumference of 15 mm from the center, and 12 holes are provided on the circumference of 25 mm from the center. A second hole 4b is opened. Here, as shown in FIG. 2B, the distance d between the grid electrodes 5 to 7 is 10 mm, and the diameter p of the first holes 4a is 20 mm, as shown in FIG. In addition, the diameter p of the second hole 4b is 6 mm. That is, the ratio (aspect ratio) p / d of the diameter p of the first hole 4a and the distance d between the grid electrodes is 1 or less (0.
6), the diameter p of the second hole 4b and the distance d between each grid electrode
The ratio (aspect ratio) p / d exceeds 1 (2.0)
It is like this.

As film forming conditions, a carbon steel sample (carbon concentration = 1% by weight) was used for the substrate 11, the degree of vacuum was 10 ⁻³ Pa or less, and the vacuum arc current was in the range of 100 A to 200 A. Moreover, 40 kV was applied as an accelerating voltage to the ion beam extraction grid electrode set 4. In addition, the vacuum plasma chamber 2 as the vacuum arc plasma generation unit is connected to the substrate 1
The distance to 1 was about 30 cm.

When treated for 25 minutes under the above conditions, 80
A carbon film 12 of 0 angstrom was obtained. on the other hand,
As a comparative material, a carbon film having almost the same film thickness was formed in a film forming time in about 4 minutes using a vacuum vapor deposition apparatus. Table 1 shows the results of the scratch test using carbon steel balls by these methods, that is, the case where the carbon film formation according to the present invention and the carbon ion beam irradiation are simultaneously performed, and the case where the film is formed only by vapor deposition.

[0019]

[Table 1]

As a result of evaluating the formed film, the film formed by the conventional apparatus was immediately peeled off by one sliding even at the lightest load of 0.2 N. The film formed by the device did not peel at all even after sliding 10 times under a high load of 1N.

[0021]

As is apparent from the above description, according to the present invention, a hole for contacting the vacuum arc plasma to take out plasma is provided in the set of ion beam extraction grid electrodes, and the vacuum arc medium such as plasma inside is provided. The particles are ejected through the holes to be introduced into the processing chamber to irradiate the material to be processed, and the ion beam extraction holes having an aspect ratio of 1 or less and the plasma extraction holes having an aspect ratio of more than 1 coexist on the grid electrode in contact with the plasma. By simultaneously irradiating the material to be treated with the plasma and the ion beam generated by the device to form a film, the structure is significantly simplified, the device cost is reduced, and the reliability is improved. However, it is possible to obtain a film with higher adhesiveness, which is more than enough to compensate for the demerit of lowering the processing speed. .

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an apparatus showing one embodiment of the present invention.

2A and 2B are enlarged views of a grid electrode, in which FIG. 2A is a front view, a cross-sectional view when the aspect ratio is 1 or less, and FIG. 2B is a cross-sectional view when the aspect ratio exceeds 1.

FIG. 3 is a schematic diagram showing a configuration of a conventional vacuum arc film forming apparatus.

FIG. 4 is a schematic diagram showing a configuration of a conventional vacuum arc ion beam irradiation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 processing chamber 2 vacuum plasma chamber 3 vacuum arc discharge electrode 4 grid electrode set 4a 1st hole 4b 2nd hole 5-7 grid electrode 8, 9 power supply 11 substrate 12 coating carbon 21 processing chamber 22 electrode 31 processing chamber 32 Vacuum plasma chamber 33 Vacuum arc discharge electrode 34 Grid electrode set 38, 39 Power supply

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[Procedure amendment]

[Submission date] October 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an apparatus showing one embodiment of the present invention.

FIG. 2 is an enlarged view of a grid electrode, (a) is a front view.
Figure, (b) is a sectional view when the aspect ratio is 1 or less,
(C) shows a cross-sectional view when the aspect ratio exceeds 1.
You

FIG. 3 is a schematic diagram showing a configuration of a conventional vacuum arc film forming apparatus.

FIG. 4 is a schematic diagram showing a configuration of a conventional vacuum arc ion beam irradiation device.

[Explanation of Codes] 1 processing chamber 2 vacuum plasma chamber 3 vacuum arc discharge electrode 4 grid electrode set 4a first hole 4b second hole 5-7 grid electrode 8, 9 power supply 11 substrate 12 coating carbon 21 processing chamber 22 Electrode 31 Processing chamber 32 Vacuum plasma chamber 33 Vacuum arc discharge electrode 34 Grid electrode set 38, 39 Power supply

Claims (1)

[Claims] 1. A vacuum arc discharge electrode for melting and evaporating a film forming material to form a film on the surface of a substrate held in a processing chamber, and a vacuum plasma chamber for confining plasma generated by the discharge. A set of grid electrodes that are provided so as to overlap between the vacuum plasma chamber and the processing chamber and that are provided with holes for taking out the plasma into the processing chamber;
In a film forming apparatus having a power source for applying a voltage to each of the electrodes, the set of grid electrodes has a ratio p / d of a hole diameter p and a distance d between the grid electrodes of more than 1. A film forming apparatus having a first hole and a second hole having the ratio p / d of 1 or less.