Growth of diamond by sequential deposition and etching process using hot filament CVD

High quality diamond films with enhanced growth rates have been grown by a sequential deposition and etching process using the hot filament CVD method. A computer is used to control the switching between a cycle of high methane-content gas mixture diluted with hydrogen, which is used for high growth rate deposition, and the other cycle of hydrogen gas only, which is used for non-diamond etching, in order to achieve high growth rate diamond deposition without sacrificing diamond quality. According to SEM and Raman spectroscopy, high quality diamond films are obtained by use of a suitable ratio of the deposition time to the etching time and a short cycling period (10 s), which is necessary to remove undesirable non-diamond components in time to grow high quality diamond. The growth rate is several times higher than that of diamond film with a similar quality deposited by the continuous diamond deposition condition using the hot filament CVD method.