Diamond film formation using RF plasma CVD assisted by water vapor enhanced hydrogen radical source

Abstract

Summary form only given. Reports on the developement of a unique plasma CVD method, "plasma CVD assisted by remote radical source", which is a novel technique to control plasma by changing densities of specific radicals while keeping the electron temperature and electron density almost constant in the plasma. This system consists of three parts, a magnet-active parallel plate RF (13.56 MHz) plasma reactor, a compact microwave (2.45 GHz) discharge region for a source of H radicals, and a CO/sub 2/ laser for the substrate heating. In this system, hydrocarbon gases are mainly excited by the parallel plate RF plasma, and we expect the effective generation of neutral radicals such as CH/sub 3/. By using remote microwave H/sub 2/ plasma, a large amount of H radicals are generated and carried into the RF plasma region. For the formation of diamond, CH/sub 3/OH and H/sub 2/ were used as the source gas mixture. By using this system diamond thin film was successfully synthesized. In addition, the effect of H/sub 2/O addition to the microwave H/sub 2/ plasma as the H radical source on the diamond film formation was investigated. It was found that the addition of an appropriate amount of H/sub 2/O to the microwave H/sub 2/ plasma enhanced etching of non-diamond phase and selective growth of diamond in the RF plasma at relatively low substrate temperature below 500 /spl deg/C.