Point defect incorporation during diamond chemical vapor deposition

Abstract

The incorporation of vacancies, H atoms, and sp2 bond defects into single-crystal homoepitaxial (100) (2×1)- and (111)-oriented chemical-vapor-deposited diamond was simulated by atomic-scale kinetic Monte Carlo. Simulations were performed for substrate temperatures from 600 to 1200 °C with 0.4% CH4 in the feed gas, and for 0.4-7% CH4 feeds with a substrate temperature of 800 °C. The concentrations of incorporated H atoms increased with increasing substrate temperature and feed gas composition, and sp2 bond trapping increased with increasing feed gas composition. Vacancy concentrations were low under all conditions. The ratio of growth rate to H atom concentration was highest around 800-900 °C, and the growth rate to sp2 ratio was maximum around 1% CH4, suggesting that these conditions are ideal for economical diamond growth under simulated conditions.