High rate diamond deposition using a microwave discharge

Summary form only given. Presently, plasma assisted synthesis of diamond films often employs a microwave discharge/reactor for the source of the radical species. Typical deposition takes place using varying CH/sub 4//H/sub 2//CO/sub n/ gas mixtures over a 20-100 Torr pressure regime and with a CW, 2.45 GHz input power of less than 3 kW. While excellent diamond films are synthesized under these conditions, the linear deposition rates are usually limited to only a few /spl mu/m/hr. Since diamond synthesis costs are still high, it is desirable to deposit high quality diamond films with higher deposition rates. One method to increase the diamond deposition rate is to increase the deposition pressure and discharge absorbed power density. This paper will present the results of an experimental investigation exploring microwave plasma synthesis at the 100-200 Torr pressure and 2.5-6 kW input power regimes. This work, which builds upon earlier reported work (Kuo et al., 1992, Kahler, 1997), utilizes a microwave reactor developed for operation at higher pressure/power regimes.