THE GROWTH OF (100) ORIENTATED DIAMOND FILMS

Quasi-equilibrium calculations were performed on the C-H and C-H-O systems to calculate the thermodynamic stability of diamond and graphite phases under CVD conditions. Exclusive diamond growth is dependent, in part, on the increased thermodynamic stability of H-terminated crystallographic surfaces. This feature was included in the methodology by estimating the surface enthalpies by group additivity methods. The lower boundary in the Bachmann ternary diagram which defines the demarcation line between the growth and non-growth regions was calculated. The gradient of the line is a strong function of the degree of stabilization of the H-terminated diamond surfaces. Using mixtures of CH4-CO-H-2 of compositions close to the CO line of the phase diagram, (100) faceted films were grown by microwave assisted CVD at rates of 1.5-2.0 mum h-1.