| 摘要 |
PROBLEM TO BE SOLVED: To obtain high purity and highly corrosion resistant silicon carbide by specifying the peak intensity ratio in the X-ray powder method to be not less than a specified value and controlling the specific resistance to be a particular value. SOLUTION: This silicon carbide has a peak intensity ratio Id1/Id2 of not less than 0.005, wherein the Id1 is the intensity of the peak when 2θ is about 34 deg. and the Id2 is the intensity of the peak when 2θ is about 36 deg., and a specific resistance of 103 to 106 Ω.cm. The silicon carbide is obtained by forming β-type silicon carbide on the surface of a base body by a CVD method and then removing the base body and heat treating the obtained β-type silicon carbide at 1,500 to 2,300 deg.C. Phase transition from the β-type to α-type in the silicon carbide is controlled to obtain the silicon carbide having a desired specific resistance and low specific resistance dispersion by the heat treatment mentioned above. It is preferable that the heat treatment is carried out at a pressure of 0.1 to 2.0 atm (absolute pressure) under an inert atmosphere such as argon or helium for 5 to 10 h and the heated silicon carbide is cooled at a cooling rate of 5 to 10 deg.C/min. In the case the silicon carbide is used as a member of a plasma treatment device, it exhibits durability to gaseous plasma while hardly containing semiconductor wafers. |
