Understanding the chemistry of low temperature diamond growth: an investigation into the interaction of chlorine and atomic hydrogen at CVD diamond surfaces

The interaction of chlorine with CVD diamond surfaces has been studied using Auger and photoelectron spectroscopy techniques, with reference to the development of low temperature growth models for diamond using halogen-based precursors. Chlorine is found to adsorb on the clean CVD surface with a sticking probability of ~0.001 at 300 K, although this can be enhanced by prehydrogenation of the surface and by raising the substrate temperature. Adsorbed chlorine desorbs from the surface over a wide temperature range below 500°C, and is also very efficiently etched away by atomic hydrogen. Chlorine has therefore little tendency to poison the growth surface, and thus is capable of acting as a catalyst for low temperature growth. (C) 2000 Elsevier Science S.A. All rights reserved