Process for the vapor phase synthesis of diamond and highly crystalline diamond

摘要

High quality diamond excellent in crystalline property as well as transparency, can be synthesized at a high growth speed by a process which comprises using, as a raw material gas, a mixed gas of hydrogen gas A, an inert gas B, a carbon atom-containing gas C and an oxygen atom- containing inorganic gas D in such a proportion as satisfying the following relationship by mole ratio:PP0.001B/(A+ B+C+ D). ltoreq.0.95PP0.001C/(A+B+C+D)0. 1P P0.0005 D/C10PPexcept that the carbon atom- containing gas C and the oxygen atom-containing inorganic gas D, cannot simultaneously be the same gas feeding the mixed gas into a reactor in which plasma is then formed by applying a DC or AC electric field at a pressure of 10 to 760 torr and thereby depositing and forming diamond on a substrate arranged in the reactor.