Claims
- 1. A process tube for fabricating a semiconductor device, said tube comprising a core of material selected from the group consisting of: sintered silicon carbide and silicon-impregnated sintered silicon carbide, at least the inner surface of said core having a layer of non-porous silicon carbide deposited thereon.
- 2. The process tube according to claim 1, wherein the silicon carbide layer is formed by chemical vapor deposition.
- 3. The process tube of claim 1, wherein the silicon carbide layer is 5.mu. to 1.mu. thick.
- 4. The process tube of claim 1, wherein the silicon carbide layer is 80.mu. to 300.mu. thick.
- 5. The process tube of claim 1, wherein the tube has the entire inner and outer surfaces coated with the silicon carbide layer.
- 6. The process tube of claim 5, wherein an insulation film is coated on the silicon carbide layer of the outer tube surface.
- 7. The process tube of claim 6, wherein the insulation film is formed of a material selected from the group consisting of alumina, silicon nitride, silicon dioxide and zircon.
- 8. In a process tube for fabricating semiconductor devices, the improvement comprising: a central core for said tube wherein said core is a material selected from the group consisting of: sintered silicon carbide and silicon-impregnated sintered silicon carbide, said tube further including means for reducing the passage of impurities from the exterior of said tube through said core, said reducing means comprising a layer of nonporous silicon carbide deposited on at least the inner surface of said tube.
- 9. The process tube of claim 8 wherein said layer is deposited by chemical vapor deposition.
- 10. The process tube of claim 9 wherein said layer is 5.mu. to 1.mu. thick.
- 11. The process tube of claim 9 wherein said layer is 80.mu. to 300.mu. thick.
Priority Claims (1)
Number |
Date |
Country |
Kind |
50-153378 |
Dec 1975 |
JPX |
|
Parent Case Info
This is a continuation of Ser. No. 935,959, filed Aug. 23, 1978, now abandoned, which is a continuation of Ser. No. 753,446, filed Dec. 22, 1976, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (7)
Number |
Date |
Country |
887037 |
Jan 1962 |
GBX |
970456 |
Sep 1964 |
GBX |
1004257 |
Sep 1965 |
GBX |
1224146 |
Mar 1971 |
GBX |
1306988 |
Feb 1973 |
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GBX |
1425965 |
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GBX |
Continuations (2)
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Number |
Date |
Country |
Parent |
935959 |
Aug 1978 |
|
Parent |
753446 |
Dec 1976 |
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