JP2001073115A - Carbon sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of nodules and prevent abnormal discharge and the reduction of the film forming rate caused by sputtering and to realize carbon sputtering for a long time. SOLUTION: In a device in which, in a vacuum treating chamber 1, the surface of a cathode 3 faced to a substrate 2 is provided with a target 4 of carbon or a composite material of carbon and silicon, the circumference of the target is covered with an earth shield 5, furthermore, the front circumference of the target is surrounded by a deposition preventive board 6, and, by plasma generated in front of the target, the target is sputtered to form a carbon thin film on the substrate, the opening edge parts 7 and 8 and the bent parts 9 and 10 of the earth shield and the deposition preventive board are formed into round shapes 13 and 14, and furthermore, coating layers 11 and 12 large in surface ruggedness such as aluminum thermal spraying layers are formed on the earth shield and the deposition preventive board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for forming a carbon thin film on a substrate using a carbon-based target.

[0002]

2. Description of the Related Art Conventionally, as a device for forming this kind of thin film, a substrate b and a carbon plate mounted on a cathode c are placed in a vacuum processing chamber a evacuated by a vacuum pump as shown in FIG. A target d in the shape of
A power is supplied to the cathode c to generate a plasma discharge between the cathode c and an appropriate anode such as a chamber wall. Ions generated in the plasma are made incident on the target d to be sputtered, and the target b is sputtered. What forms a carbon thin film (DLC: diamond-like carbon) is known.
In order to prevent the target other than the target d from being sputtered, the periphery thereof is covered with a stainless steel earth shield e, and the front periphery is surrounded by a stainless steel cylindrical anti-blocking plate f so that sputtered particles are not diffused. In.

[0003]

In the above-described carbon sputtering apparatus, if sputtering is continued for a long time, nodules (blisters) are generated on the surface of the target d, thereby causing abnormal discharge or reducing the film forming rate. There was an inconvenience of causing adverse effects such as doing so.

An object of the present invention is to suppress the generation of nodules to prevent abnormal discharge and a reduction in film forming rate due to carbon sputtering, thereby enabling long-time carbon sputtering.

[0005]

According to the present invention, a target made of carbon or a composite material of carbon and silicon is provided on a cathode facing a substrate in a vacuum processing chamber. In a device for forming a carbon thin film on the substrate by sputtering the target by plasma generated in front of the target and surrounding the front periphery of the target with a deposition-preventing plate, the opening edges of the earth shield and the deposition-preventing plate and The above object is achieved by forming the bent portion in a round shape and forming a coating layer having a large surface irregularity such as aluminum, an aluminum alloy, and alumina on the earth shield and the shield plate. Preferably, the curvature of the round shape is 0.3 mm or more, and the coating layer may be formed by thermal spraying.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. 2. In FIG. 2, reference numeral 1 denotes a vacuum processing chamber evacuated by a vacuum pump, and 2 denotes a vacuum processing chamber fixed or FIG. 2 shows a substrate held by a movable substrate holding device, and a plate-like carbon or a composite material of carbon and silicon (SiC _X ) is formed on a cathode 3 such as a magnetron cathode provided opposite to the substrate 1. The target 4 was provided by bonding. The periphery of the target 4 is covered with an annular earth shield 5 made of stainless steel for preventing spatters other than the target 4, and the target 4 is prevented from diffusing in a direction other than the substrate 1 by sputtering. The front periphery was covered with a stainless steel cylindrical anti-adhesion plate 6. The deposition-preventing plate 6 was composed of an outer plate 6a and a perforated metal plate 6b along the inside thereof, and a chimney 16 was formed therebetween.

Such a structure is the same as that of the prior art, in which a negative voltage is applied to the cathode 3 from, for example, a DC power source to cause discharge between the cathode 3 and the chamber wall at the ground potential, and the plasma is forwarded to the cathode 4 in front of the target 4. When converged by the magnetic field of 3, the ions generated in the plasma enter the target 4 and sputter it, and the sputtered carbon particles adhere to the surface of the substrate 2 in a thin film. Is reached, nodules (blisters) are generated on the target 4 to cause the above-mentioned inconvenience.
This nodule is generated because a part of the sputtered carbon particles adheres to the earth shield 5 and the deposition-preventing plate 6 to form a carbon film. However, when this carbon film is released, charges concentrate and flow into it, causing abnormal discharge. The abnormal discharge causes the carbon film to peel off and fly in the direction of the target 4, resulting in the formation of nodules. I understood.

In the present invention, in order to eliminate the clarified cause, the outer plate 6a constituting the earth shield 5 and the shield plate 6 is provided.
And each opening edge 7, 8 and bent portion 9, of the perforated metal plate 6b,
10 is formed into round shapes 13 and 14 having no corners, and the earth shield 5, the outer plate 6a of the deposition-preventing plate 6 and the perforated metal plate 6b are coated with a coating layer 11 having a large unevenness on the surface of aluminum, aluminum alloy, alumina or the like. , 12 were formed by thermal spraying. As shown in the partial enlarged view of FIG. 2, each of the opening edges 7 and 8 is rounded and cut, and the bent portions 9 and 10 are bent.
Are preferably formed by bending, and these round shapes preferably have a curvature radius of 0.3 mm or more. By forming this round shape, the stress of the carbon film attached thereto is reduced, and a coating layer of aluminum or the like having a good adhesion of the carbon film is formed, so that it is not easily peeled off from the attached surface. become. Therefore, abnormal discharge is reduced, the carbon film adhered to the surface of the target 4 is also reduced, and the generation of nodules on the target 4 is also reduced. Therefore, the sputtering area is hardly reduced by the nodules, and the film forming speed is hardly reduced. .

In the carbon sputtering apparatus having the structure shown in FIG. 2, the aluminum spraying treatment was applied to the earth shield and the deposition-preventing plate, the sputtering was performed for a long time by DC magnetron sputtering, and the number of times of abnormal discharge was measured. As shown by the curve A in FIG. 3, the number of times the conventional openings and bent portions shown by the curve B in FIG. Further, the state of the target surface after the prolonged sputtering is as shown in FIG. 4A, and nodules C are slightly generated. FIG.
(B) shows the surface state of the target of the conventional example of FIG. 1 for comparison, in which a large amount of nodules is generated. still,
In this case, a power of ² W / cm ² was applied to the carbon target 4, an argon gas was used as a film forming gas, and the pressure in the vacuum processing chamber 1 was set to 2.7 × 10 ⁻¹ Pa.

In the above embodiment, the target 2 is disposed below the substrate 2 and the target 4 is disposed below.
The substrate 2 and the target 4 may be arranged vertically.

[0011]

As described above, according to the present invention, in a carbon sputtering apparatus in which the periphery of a target made of carbon or a composite material of carbon and silicon is covered with an earth shield and the front periphery thereof is surrounded by a deposition-preventing plate. Since the opening edge and the bent portion of the shield and the attachment plate are formed in a round shape, and a coating layer having a large surface irregularity such as an aluminum sprayed layer is formed thereon, generation of nodules is suppressed, and abnormal discharge caused by carbon sputtering. In addition, there is an effect that a reduction in the film formation rate is prevented, carbon sputtering can be performed for a long time, and productivity is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a conventional carbon sputtering apparatus.

FIG. 2 is a cutaway side view showing an embodiment of the present invention.

FIG. 3 is a measurement diagram of the number of abnormal discharges

FIG. 4 is a surface state diagram of a target.

[Explanation of symbols]

1 vacuum processing chamber, 2 substrates, 3 cathodes, 4 targets, 5 earth shields, 6 deposition plates, 7.8 opening edges, 9/10 bends, 11/12 coating layers, 13.14 round shapes,

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[Procedure amendment]

[Submission date] September 9, 1999 (September 9, 1999)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

According to the present invention, a target made of carbon or a composite material of carbon and silicon is provided on a cathode facing a substrate in a vacuum processing chamber. In a device for forming a carbon thin film on the substrate by sputtering the target by plasma generated in front of the target and surrounding the front periphery of the target with a deposition-preventing plate, the opening edges of the earth shield and the deposition-preventing plate and by forming a large coating layer on the front surface irregularities on the earth shield and the deposition preventing plate so as to form a bend in the round, and so as to achieve the above object. Preferably, the curvature of the round shape is 0.3 mm or more, and the coating layer may be formed by thermal spraying.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Michio Ishikawa 523 Yokota, Yamatake-cho, Yamatake-gun, Chiba Prefecture Japan Vacuum Engineering Co., Ltd. Chiba Super Materials Laboratory F-term (reference) 4K029 BA34 CA05 DA10 DC05 DC12 DC15 DC20 DC39 4K031 AA04 AA08 AB07 CB37 CB39 CB43

Claims (3)

[Claims] 1. A target made of carbon or a composite material of carbon and silicon is provided on a cathode opposed to a substrate in a vacuum processing chamber, the periphery of the target is covered with an earth shield, and the front periphery of the target is covered with a deposition preventing plate. In an apparatus for forming a carbon thin film on the substrate by sputtering the target with plasma generated in front of the target and surrounding the target, the opening edges and the bent portions of the earth shield and the deposition preventing plate are formed in a round shape. And a coating layer having a large surface unevenness formed on the earth shield and the deposition-preventing plate. 2. The carbon sputtering apparatus according to claim 1, wherein the radius of curvature of the round shape is 0.3 mm or more. 3. The carbon sputtering apparatus according to claim 1, wherein the coating layer is a layer formed by a thermal spraying method.