Diamond synthesis from CH sub(4)-H sub(2)-O sub(2) reaction gas using microwave plasma CVD

Synthesis of diamond using mode-translation type microwave plasma CVD from a CH sub(4)-H sub(2)-O sub(2) reaction gas system was investigated. Diamond could not be synthesized by addition of O sub(2) at low CH sub(4) flow rate. On the other hand, diamond could be synthesized by addition of small amounts of O sub(2) at high CH sub(4) flow rate. The area of film formation was extended by addition of O sub(2) at high CH sub(4) flow rate. Moreover, the quality of diamond produced using the CH sub(4)-H sub(2)-O sub(2) reaction gas system was almost the same as that obtained using the CH sub(4)-H sub(2) reaction gas system and the diamond deposition rate was increased by addition of small amounts of O sub(2) at high CH sub(4) flow rate. In conclusion, the deposition rate and quality of diamond were improved by addition of small amounts of O sub(2) at high CH sub(4)flow rate in this system.