JPH0450185A - Glassy carbon-coated product - Google Patents

Abstract

PURPOSE:To obtain a glassy carbon-coated product having great dusting preventive effects by coating an inorganic substrate with glassy carbon and then specifying the regular reflectance thereof. CONSTITUTION:The aforementioned product is obtained by coating an inorganic substrate with glassy carbon. The regular reflectance thereof is 2-19%. In the aforementioned coated product, if the regular reflectance is <2%, preventive effects on dusting are small. On the other hand, the reflectance exceeds 19%, peeling of the glassy carbon coating layer readily occurs. The reason why the regular reflectance on the surface of the glassy carbon-coated product is closely related with the dusting amount is considered as follows. The regular reflectance is a measure indicating the smoothness of surface conditions. The dusting properties, i.e., eliminating properties of constituent particles and adhesion and the eliminating properties of adhered particles are strongly affected by the smoothness of the surface conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a glassy carbon-coated article that is highly effective in preventing dust generation.

(Prior art) By coating an inorganic substrate, such as a graphite substrate, with glassy carbon, it is possible to prevent dust generation from the substrate, moisture absorption or gas adsorption, prevention of impurity contamination, and improvement of biocompatibility in biorepair materials. Furthermore, it is used in industrial applications because it has effects such as imparting gas impermeability.

For example (Japanese Patent Publication No. 52-39684, Japanese Unexamined Patent Publication No. 62-1988)
207785, JP 62-252394, JP 62-270489, JP 63-54
(See Publication No. 729).

Among the above effects, the dust generation prevention effect is attracting attention because it directly contributes to improving the performance and reducing the defective rate of various semiconductor-related products, for example, and the development of glassy carbon-coated articles that have a greater dust generation prevention effect is in progress. desired.

(Problems to be Solved by the Invention) An object of the present invention is to provide a glassy carbon-coated article that has a large dust generation prevention effect.

(Means for Solving the Problem) In order to achieve the above object, the present inventors conducted various studies on the relationship between the surface coating state and the dust generation mechanism, and found that the specular reflectance of the surface of a glassy carbon coated article and the dust generation mechanism were It was discovered that there is a close relationship between the amount generated and the present invention was completed.

That is, the present invention is a glassy carbon-coated article in which an inorganic substrate is coated with glassy carbon, and the specular reflectance thereof is 2 to 19%.

The present invention will be explained in more detail below.

The materials of the inorganic substrate used in the present invention include graphite,
Any type of material such as alumina, silicon carbide, silicon nitride, aluminum nitride, mullite, etc. can be used, and therefore, a typical graphite substrate in this field will be described below as an example.

A graphite substrate is generally an aggregate of graphite particles having a particle size of several hundred μm or less. Dust is particles that are detached from these constituent particles or particles attached to the constituent particles from the outside due to mechanical, thermal, or electrical shocks. Therefore, in order to prevent the generation of this dust, it is necessary to prevent the constituent particles and attached particles from detaching, and one example of a method for preventing this is to coat the surface of the substrate with glassy carbon.

In the present invention, the surface regular reflectance of the glassy carbon-coated article is set to 2 to 19%. If the regular reflectance is less than 2%, the effect of preventing dust generation is small (on the other hand, if it exceeds 19%, the glassy carbon coating layer is likely to peel off).

The reason why there is a close relationship between the specular reflectance of the surface of a glassy carbon-coated article and the amount of dust generated is that the specular reflectance is a measure of the smoothness of the surface condition, and it is also a measure of the dust generation, that is, the shedding of constituent particles. We believe that this is because the releasability and adhesion and releasability of adhered particles are strongly influenced by the smoothness of the surface condition.

When the surface of the substrate is rough, the surface is covered with particles that are easily detached, and dust is likely to be generated. Even if this is coated with glassy carbon, particles are detached with the coating layer still attached and dust is generated. Further, if the surface after coating is rough, for example, when a mechanical impact is applied, the convex portions of minute irregularities on the surface will be chipped and dust will be generated. The rough surface referred to here means that it can be seen under a microscope or SEM.
This refers to a state in which the morphology of the constituent particles of the substrate can be observed on the surface after glassy carbon coating. In this state, most of the light incident on the surface of the glassy carbon coated article is absorbed by the substrate. The minute irregularities on the surface, which are traces of the constituent particles, cause diffuse reflection. On the other hand, when the surface is smooth, the above problem does not occur and the amount of dust generated is significantly reduced. In this state, a part of the light incident on the surface of the glassy carbon coated article is reflected specularly. I come to do it.

For the above reasons, in the present invention, the specular reflectance of the glassy carbon coated article is set to 2 to 19%, and in order to manufacture a glassy carbon coated article having such a specular reflectance, After smoothing the surface of the substrate, a glassy carbon coating may be applied.

Conventional polishing methods using puffs, pads, brushes, sandpaper, etc. are sufficient for smoothing the surface of the substrate, but if puffs or pads are used, the particles removed by polishing may enter the pores of the substrate. This has the advantage of increasing gas impermeability after coating with glassy carbon. Note that the regular reflectance of the base is the same as the regular reflectance due to the glassy carbon coating.
It is desirable to determine the polishing conditions in consideration of the knob, and the polishing conditions and coating layer thickness are appropriately determined in consideration of the type of substrate to be used and the shape, particle size, particle size distribution, etc. of the constituent particles.

The inorganic substrate may be coated with glassy carbon by coating the surface of the substrate with a solution of a thermal decomposition product of an organic polymer dissolved in a solvent, followed by baking in an inert or vacuum environment. Examples of organic polymers include vinyl chloride resin,
Examples include polyvinyl alcohol, oil-soluble phenol resin, alkylphenol resin, chlorinated paraffin, chlorinated polypropylene, vinyl acetate resin, polycarbonate resin, and among the above, vinyl chloride resin is particularly preferred from the viewpoint of impurities.

(Example) Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

1-3 6 1-2 The surface of isotropic graphite with a bulk specific gravity of 1.85 and a surface specular reflectance of 0.2% is coated with an industrial pad (Scotch ply) 74
48) to give a surface specular reflectance of 8%.

On the other hand, polyvinyl chloride was thermally decomposed at 390°C in nitrogen to obtain a tar-like carbon precursor, this carbon precursor was dissolved in trichlene, and after coating it on the above isotropic graphite, it was placed in a vacuum atmosphere. Baked at 1200″C, specular reflectance is 9%, 15
%, 19%, and 20% glassy carbon coated articles, respectively.

4-5, 3-4 The surface of extruded graphite material with a surface specular reflectance of 0.1% and a bulk specific gravity of 1.60 is coated with an industrial pad (Scotchbrai) 74
4B) to give a surface specular reflectance of 1%.

The surface of this extruded graphite material was coated with glassy carbon in the same manner as in Examples 1 to 4, and the specular reflectance was 1.8% and 2%.
, 5% glassy carbon coated articles were prepared, respectively.

The specular reflectance and dust amount of the glassy carbon coated articles obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were measured, and the results are shown in Table 1.
The results were obtained. The physical property values listed in Table 1 were measured by the following method.

(1) Specular reflectance (%) 3 using glossy needle GM-060 (manufactured by Minolta Camera Co., Ltd.)
Measures the regular reflectance of 0° incident light.

(2) Dust amount (pieces/crA-min) glass cell (1
Place the sample (7 x 7 x 7, 3 pieces) in a 5φ x 30 #),
Vibration was applied at an amplitude of 0.05 f 160 Hz, and the number of particles larger than 0.3 μm was measured with a particle counter.

(Effects of the Invention) Since the glassy carbon-coated article of the present invention has a large dust generation prevention effect, it greatly contributes to improving the performance of, for example, semiconductor-related products manufactured using the same, and reducing the defective rate.

The glassy carbon-coated article of the present invention is used in a wide range of industrial fields such as chemicals, semiconductors, nuclear power, and aerospace. Specific examples include various susceptors, diodes,
transistor.

Various jigs used for assembly of semiconductor electronic parts such as IC, chemical processing manufacturing, inspection, etc.;
Crucibles used for evaporation, reduction purification, etc., various parts used in equipment that melts semiconductor raw materials at high temperatures and performs various processes such as single crystallization and purification of semiconductors, boats used in liquid phase epitaxial growth processes, and various reactions. Such as pipes.

Patent applicant: Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A glassy carbon-coated article comprising an inorganic substrate coated with glassy carbon and having a specular reflectance of 2 to 19%.