JPH06140349A - Jig for semiconductor heat treatment - Google Patents

Abstract

PURPOSE:To prevent the impurity diffusion from silicon carbide by forming a CVD coating film so that no thermal stress causing breakage is not applied to the surface of a jig for semiconductor heat treatment made of silicon carbide. CONSTITUTION:On the surface of a jig 1 for semiconductor heat treatment made of silicon carbide, a CVD coating film 2 finely partitioned as tiles is formed. As the material for the CVD coating film, there are polysilicon film and SiC film for example. In addition, the film thickness is made sufficient so as to prevent diffusion of metal impurities. By finely partitioning the CVD coating film, the function of suppressing the metal impurity diffusion from the silicon carbide is maintained and the effect of preventing breakage due to a thermal stress is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor heat treatment jig, and more particularly to a surface structure of a jig made of silicon carbide.

[0002]

2. Description of the Related Art Heat treatment jigs such as furnace core tubes, indenting furnaces for semiconductor processes such as boats, and oxidizing furnaces are often made of quartz glass due to the required purity. Recently, instead of this, a material made of silicon carbide, which is superior in heat resistance, has been adopted.

In particular, in order to prevent scattering of impurities contained in silicon carbide, a heat treatment jig having a CVD coating film formed on the surface of silicon carbide has been newly adopted. FIG. 3 is a partial sectional view of a conventional semiconductor heat treatment jig. In the figure, 1 is silicon carbide and 2 is a CVD coating film.

[0004]

By the way, the jig for heat treatment in which the CVD coating film is formed on the surface of silicon carbide is used in a high temperature furnace (1000 ° C. to 1400 ° C.) utilizing its heat resistance. Therefore, there is a drawback that the thermal stress between the silicon carbide and the CVD coating film of the surface layer easily leads to damage.

Further, if the CVD coating film is thinned to reduce the thermal stress, there is a drawback that metal contamination of the semiconductor material from impurities contained in silicon carbide cannot be suppressed.

[0006]

According to the present invention, in a semiconductor heat treatment jig, a CVD coating film is formed on the surface of silicon carbide, and the CVD coating film is divided into small areas, and the portion is formed into a film. Is characterized in that a thin groove is formed.

[0007]

According to the above structure, the C formed on the surface of the jig
The VD coating film functions as a mask material that prevents metal impurities contained in silicon carbide from diffusing into the semiconductor material during heat treatment of the semiconductor material. Further, even if a thermal stress acts between the silicon carbide and the CVD coating film during the heat treatment of the semiconductor material, the CVD coating film is partially divided, so that the large stress that causes the damage does not occur and the damage does not occur.

Further, although a thin portion (groove) of the CVD coating film is formed, the area of the groove portion is very small compared to the entire coating area, so that the function of the metal impurity as a mask material is not impaired.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1A is a partial sectional view of a heat treatment jig for semiconductor diffusion according to an embodiment of the present invention. FIG. 1B is an enlarged view of part 4 of FIG. Reference numeral 1 is silicon carbide, and 2 is a CVD coating film formed by being finely divided. As a CVD coating film, a polySi film S
An iC film or the like can be used. According to this example, since the CVD coating film formed on the surface of silicon carbide is finely divided like a tile, even if stress is generated due to thermal stress with silicon carbide, it becomes a partial stress, which causes damage. There is an advantage that it is difficult to connect. In addition, it is possible to form a thick CVD coating film, which has an advantage that diffusion of impurities from silicon carbide can be easily suppressed. Regarding the manufacturing method, the following method can be given as an example. First, a CVD coating film is first formed on the entire surface of the jig. Next, the cover film is attached only to the portion where the coating film remains on the CVD coating film. Then, etching is performed to thin the CVD coating film in the groove. Finally, the cover film is removed.

[0011]

[Embodiment 2] FIG. 2A is a longitudinal sectional view of a second embodiment of the present invention. FIG. 2B is an enlarged view of the four parts. 1
Is a silicon carbide, and 2 is a CVD coating film finely divided by V-shaped grooves. As the CVD coating film, a polySi film, a SiC film, or the like can be used. According to this embodiment, since the CVD coating film formed on the surface of silicon carbide is finely divided by the V-shaped groove, even if stress is generated by the silicon carbide and thermal stress, it becomes a partial stress and breaks. There is an advantage that it is difficult to connect to. In addition, the V-shaped groove has a small exposed area of silicon carbide, which is advantageous in that the scattering of impurities can be easily minimized.

The following method may be mentioned as an example of manufacturing. First, a CVD coating film is first formed on the entire surface of the jig. Next, CV with a V-shaped cutter
The D coating film is cut to form a V-shaped groove.

[0013]

As described above, according to the present invention, a CVD coating film is partially formed on the surface of a jig so that the damage can be reduced due to thermal stress, and a thicker CVD coating is available. By using the film, the amount of heavy metals such as iron, nickel, chromium, and copper that contaminate the semiconductor material can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a semiconductor heat treatment jig according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a semiconductor heat treatment jig according to another embodiment of the present invention.

FIG. 3 is a partial sectional view of a conventional semiconductor heat treatment jig.

[Explanation of symbols]

 1 Silicon Carbide 2 CVD Coating Film 3 Grooves in CVD Coating Film

Claims (4)

[Claims] 1. A jig for semiconductor heat treatment made of silicon carbide, wherein a CVD coating film is formed on the surface of silicon carbide, and a groove portion for dividing into a small area is formed on the CVD coating film. Jig for semiconductor heat treatment. 2. The jig for semiconductor heat treatment according to claim 1, wherein the groove has a thin CVD coating film. 3. The jig for semiconductor heat treatment according to claim 1, wherein the groove is formed in a substantially cross-sectional direction. 4. The jig for semiconductor heat treatment according to claim 1, wherein the groove is formed in a V-shaped cross section.