Claims
- 1. A method of manufacturing a resistance body for an electric resistor, said resistance body consisting of p-type doped pyrolytic polycrystalline cubic silicon carbide, said method consisting essentially of passing a mixture of a gaseous silicon compound, a gaseous carbon compound or a gaseous silicon carbon compound and a gaseous compound of a doping element, said doping element being only a p-type doping element, along a support heated to the pyrolysis temperatures of said gaseous compounds to thereby cause pyrolysis of said gaseous compounds and cause deposition on said support only of a compact coating of p-doped polycrystalline cubic silicon carbide on said support.
- 2. A method as claimed in claim 1, characterized in that a conducting or non-conducting wire or tape-shaped support is used.
- 3. A method as claimed in claim 2, characterized in that a wire consisting of an element of the group consisting of tungsten, carbon and molybdenum is used as a support.
- 4. A method as claimed in claim 3, characterized in that a compound of boron is used as a compound of a doping element.
- 5. A method as claimed in claim 3, characterized in that a compound of aluminum is used as a compound of a doping element.
- 6. A method as claimed in claim 4, characterized in that the compound of boron at a pyrolysis temperature between about 1200.degree. and about 1350.degree. C. is used in a concentration in the range between 5.10.sup.-3 % by volume and 7.10.sup.-1 % by volume of the pyrolysis gas.
- 7. A method as claimed in claim 4 characterized in that the compound of boron at a pyrolysis temperature between about 1350.degree. C. and about 1500.degree. C. is used in a concentration in the range between 2 10.sup.-3 % by volume to 5.10.sup.-2 % by volume of the pyrolysis gas.
- 8. A method as claimed in claim 5, characterized in that the compound of aluminum at a pyrolysis temperature of between about 1200.degree. and 1500.degree. C. is used in a concentration in the range between 0.003% by volume and 0 0.03% by volume of the pyrolysis gas.
Parent Case Info
This is a division of application Ser. No. 615,695, filed Sept. 22, 1975 now U.S. Pat. No. 4,086,559.
This application is a continuation-in-part of copending U.S. patent application Ser. No. 504,912, filed Sept. 11, 1974 and now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
3157541 |
Heywang et al. |
Nov 1964 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
615695 |
Sep 1975 |
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