Diamond synthesizing apparatus.

摘要

A diamond synthesizing apparatus comprises a reaction tube for internally making reaction for vapor-phase synthesizing diamond, and plasma generation means for generating prescribed microwave plasma in this reaction tube. The reaction tube is coupled with a gas reservoir, which defines a circulation system with the reaction tube. The circulation system comprises means for evacuating its interior. This circulation system further comprises means for circulating raw material gas, which is a compound containing carbon, in a sealed state, and raw material gas supply means for intermittently or continuously supplying the raw material gas into the circulation system. According to this diamond synthesizing apparatus, it is possible to suppress pressure fluctuation and composition fluctuation following reaction and gas addition to the minimum and to vapor-phase synthesize diamond in extremely restricted ranges of gas composition and pressure. Further, consumption of the raw material gas is extremely reduced and gas concentration in the reaction tube is extremely slowly and smoothly changed in gas supply, whereby it is possible to suppress influence exerted by the changes in gas concentration to the film quality.