JPH02173269A - Carbon jig for cvd device - Google Patents

Abstract

PURPOSE:To develop a carbon jig excellent in mechanical strength, resistance to chemicals, resistance to oxidation and durability by filling glassy carbon into the opened holes of carbon base material of the carbon jig in a CVD device and thereafter forming a glassy carbon film on the surface thereof. CONSTITUTION:A carbon jig such as a carbon plate and a carbon disk electrode is utilized for a CVD device and has 1.50-1.90g/cm<3> bulk density. The base material 1 of this carbon jig is impregnated with thermosetting resin such as phenolic resin and furan resin and held e.g. at 80 deg.C for one day and made a semicured state. Furthermore the same kind of thermosetting resin is applied thereon and heated at about 200 deg.C to cure resin. Thermosetting resin is converted into glassy carbon by performing heat treatment at 2000 deg.C in the inert atmosphere. Glassy carbon 3 is filled into the opened holes 2 of the carbon base material 1 and a film 4 made of glassy carbon is formed on the surface thereof and thereby the carbon jig is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a carbon jig for CVD equipment, and in particular is used in hot wall type plasma CVD equipment, etc. that forms thin films on silicon wafers for semiconductor devices. The present invention relates to a carbon jig for a CVD apparatus such as a carbon plate or a carbon disk electrode or a connecting member between electrodes.

[Conventional technology]

Conventionally, this type of carbon jig has been used in the process of pulverizing coke to produce a powdered carbon material, adding an appropriate binder to the powdered carbon material and kneading it, and molding a mixed wire material to form a molding element. It was produced through a process of producing a body, firing the molded body, and graphitizing the fired body by heat treatment.

The carbon jig is used as an electrode to perform appropriate heat treatment on the silicon wafer for semiconductor devices when it is inserted into a hot-wall type plasma CVD apparatus. Ta. Therefore, nitrides or oxides are also deposited on the carbon jig, and as the jig is used over and over again, it gradually becomes difficult to generate stable plasma, which in turn makes it difficult to form a uniform CVD film on silicon wafers for semiconductor devices. Therefore, it was necessary to remove the adhered nitrides or oxides, and the carbon jig was periodically cleaned using Freon gas or the like.

With this periodic cleaning, carbon particles tend to fall off from the carbon jig, and there is a risk that they may fall off and adhere to silicon wafers for semiconductor devices during plasma CVD processing. In order to prevent this, a glassy carbon film or a pyrolytic carbon film was formed on the surface of the carbon jig.

In order to solve the above problem, this is a carbon jig in which a coating 12 of glassy carbon or pyrolytic carbon is formed on the surface of a carbon base material U, as shown in FIG. In the figure, 13 is an open hole.

[Problem to be solved by the invention]

However, in the conventional carbon jig for CVD equipment described above, a coating of glassy carbon or pyrolytic carbon is simply placed on the surface of the carbon base material.
The mechanical strength of the coating itself was insufficient, and it did not fully satisfy the requirements for solving the problem. On the other hand, if you try to thicken the film to increase the strength of the film, cracks and peeling will occur in the film due to differences in thermal expansion during the heat treatment process during film formation, resulting in a thick film (5- or more). It was difficult to do so.

Therefore, an object of the present invention is to provide a carbon jig for a CVD device that can increase the thickness of the glassy carbon film to improve mechanical strength and, in turn, significantly improve chemical resistance, oxidation resistance, and life. shall be.

[Means to solve the problem]

In order to solve the above problems, the present invention fills open pores in a carbon base material with glassy carbon, and forms a film of glassy carbon on the surface of this carbon base material.

The bulk density of the carbon base material is 1.50 to 1.90 g/c
It is effective to set it to ffl.

The filling ratio of glassy carbon to the open pores is preferably 60% or more.

The film J¥ of the film is preferably 2 μs to 1 axis.

The open porosity of the coating is preferably 0.1-1.0%.

[For production]

In the above means, the open pores in the carbon substrate are reduced by filling with glassy carbon, and the amount of gas or liquid filled in the carbon substrate is reduced, while the filled glassy carbon is filled with the same kind of coating. Become an anchor.

If the bulk density of the carbon base material is less than [,50 g/cj, the mechanical strength will decrease, but if the bulk density is 1690 g
/ aid, the cost will be high.

If the filling ratio of glassy carbon to the open pores is less than 6096, the coating will crack or peel due to the gas or liquid filled in the carbon base material, and the force for holding the coating will be reduced.

If the film thickness of the film is less than 2 mm, it will not be effective as a film, and if it exceeds 1 thickness, cracks or peeling will occur due to shrinkage during the heat treatment process for film formation.

If the open porosity of the coating is less than 0.1%, the gas or liquid present in the carbon base material will cause cracks and peeling of the coating when the temperature rises and cools during use, resulting in a significant reduction in the life of the coating, which is undesirable. do not have.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

After impregnating various types of carbon base materials with thermosetting resins (such as phenolic resins and furan resins) under reduced pressure, they are kept at 80°C (78°C) for one day to semi-cure, and then the same type of thermosetting resin is added thereto. The surface of the carbon base 1 is coated, and then the thermosetting resin is cured by holding it at a temperature of 200°C for 1 hour, and then heat-treated at a temperature of 2000°C in an inert atmosphere to harden the thermosetting resin. As shown in FIG. 1, the open pores 2 of the carbon base material 1 are filled with glassy carbon 3, and a coating 4 of glassy carbon is formed on the surface of the carbon base material 1. CV
A carbon jig for D1 placement was obtained.

The bulk density, porosity, bending strength, and life of each carbon jig are shown in Table 1, which also includes comparative examples.

Accordingly, the bulk density of the carbon base material is l, 50 to 1.90.
It can be seen that the bending strength and life can be improved by setting the ratio to g/- and the porosity of the coating to 0.1-1.0%.

Then, the filling ratio of glassy carbon to the open pores is:
60% or more is preferable, and the film JV of the film is 2 μs to
The range l11111 was preferred.

In addition, the carbon jigs of the above examples and conventional examples, as well as the untreated carbon jigs that do not form a film, were subjected to an oxidation consumption test (8
When the sample was left in air at a temperature of 00°C), the result was as shown in Figure 2.

Therefore, the product of the present invention has a low weight loss rate even after 60 minutes,
While it can be seen that the oxidation resistance is extremely excellent, the untreated product almost loses its shape after 60 minutes, and the conventional product has a high ff1ffi reduction rate after 30 minutes, indicating that the oxidation resistance is poor. You can see that it will become inferior. This is because the glassy carbon coating was oxidized and deteriorated, and cracks were generated in the coating due to the expansion of gas in the open pores, resulting in peeling and the carbon base material being directly affected by oxidation.

〔Effect of the invention〕

As described above, according to the present invention, the open pores in the carbon base material are reduced by filling with glassy carbon, and the amount of gas or liquid filled in the carbon base material is reduced. Since it serves as an anchor for a similar type of coating, it is possible to increase the thickness of the coating and improve its mechanical strength, which in turn can significantly improve chemical resistance, oxidation resistance, and life.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a carbon jig for a CVD apparatus showing an embodiment of the present invention, Fig. 2 is an explanatory view of the results of an oxidation consumption test, and Fig. 3 is an explanatory view of a conventional carbon jig for a CVD apparatus. It is. ]...Carbon base material 2...Open pores 3...
Glassy carbon 4...Coating Figure 1 Figure 3 Figure 2 Applicant Toshiba Ceramics Corporation Nan 7#/Mui-Iku (column in)

Claims (1)

[Claims] (1) A carbon jig for a CVD apparatus, characterized in that open pores in a carbon base material are filled with glassy carbon, and a film of glassy carbon is formed on the surface of the carbon base material.