| 摘要 |
PURPOSE:To obtain high-purity diamond at a high growth rate, by feeding a hydrogen-containing gas for forming a sheath around a plasma in synthesizing the diamond utilizing a thermal plasma produced in a reaction tube. CONSTITUTION:Air in an apparatus is excluded through a conduit 4 communicating to a pump and decompressed and an inert gas, such as Ar, is introduced through the conduit 4 to provide atmospheric pressure. A conduit 5 is then opened to introduce a gas for generating a plasma from an introduction port 8 and a torch 2 is ignited with a high-frequency igniter to provide a stable arc plasma. When the plasma stable under ordinary pressure is obtained, a hydrogen-containing gas is initially introduced from introduction ports 10 so as to wrap a plasma flame. A carbon source is then introduced from an introduction port 9, exposed to a high temperature in the plasma and vaporized or decomposed to form active species. If a substrate is installed, diamond is produced in the formed of a film on the surface of the substrate. Unless the substrate is installed, the diamond is separated as power in the space and deposited on the inner wall and bottom of a vessel 3. |
