Diamond deposition at low temperature by using CH4/H2 gas mixture

The smooth (111) oriented diamond film with the grain size of 100-200 nm has been deposited from CH4/H-2 source gas at substrate temperature of approximately 500 degreesC by using electron-assisted chemical vapor deposition (EACVD) technique. The mechanism of diamond growth at low temperature is investigated in this paper. A quantitative estimation of minimum temperature for diamond deposition is performed through the relationship between the substrate temperature and the energy carried by the carbonaceous fragment., Diamond growth at low temperature in EACVD is simulated by Monte-Carlo method. The spatial distribution of H atoms and CH, radicals is obtained and the mobility energy of CH3 fragment under the typical experiment conditions is also calculated to estimate the deposition temperature. The results from Monte-Carlo simulation are in good agreement with those from EACVD experiment. (C) 2002 Elsevier Science B.V. All rights reserved.