Diamond-vapour interface and processes proceeding on it during growth of diamond crystals II. Diamond (011) face

Abstract

Results of a thermodynamic analysis of processes proceeding on the vapour-diamond (001) interface in hydrogen and hydrocarbon-hydrogen gas environments are presented. The calculations were performed under the assumption that hydrogen addition reactions dominate because they are much faster than hydrogen abstraction and graphite etching reactions. It is shown that atomic hydrogen, H, plays a crucial role in the diamond CVD processes, which consists of preventing the formation of sp 2-hybridized carbon structures and promoting the formation of sp 3-hybridized carbon structures. In the presence of a super-equilibrium concentration of H, the formation of graphite cannot successfully compete with that of diamond. The analysis shows, in accord with recently published experimental results, that both the diamond film phase purity and the growth rate should increase with increasing concentration of H. The analysis also suggests that various structural defects can be created relatively easily in diamond films deposited on the (011) face, and thus, contrary to expectations, the production of epitaxial (011) films of high structural perfection may be difficult.