Large area deposition of 〈100〉-textured diamond films by a 60-kW microwave plasma CVD reactor

Abstract

Diamond films were deposited on silicon wafers of 25–152 mm in diameter by a 60-kW 915-MHz plasma CVD system with a input power of 15–60 kW at a gas pressure of 11.3–17.7 kPa using H2CH4 or H2CH4CO2 gas mixtures. Growth orientation of the diamond films and α parameters for the different growth conditions have been investigated in order to control the morphology of the diamond films of 152 mm in diameter. It was clearly seen that the α parameters for the 60-kW system were greater than those for conventional microwave plasma CVD systems in the substrate temperature–CH4 concentration plane. This means that the contour of the α parameter shifts to the higher substrate temperature and the lower CH4 concentration, as compared with the results of the conventional CVD systems. It was also found that the parameter range of diamond growth by the 60-kW reactor is broader than that of the conventional CVD systems. Based on the present study, 〈100〉-textured diamond films were successfully grown almost uniformly on the entire surface of a 152-mmφ Si substrate by choosing appropriate process conditions.