Preparation of diamond/silicon carbide films with gradient composition

Diamond/SiC compositional gradient films were deposited by the microwave plasma CVD, using a gas mixture of hydrogen, methane and tetramethylsilane (TMS). Single crystalline silicon wafers, pretreated with nano-diamond particles before deposition, were used as substrates. The films were characterized by scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and energy-dispersive x-ray analysis (EDX). The results show that the content of diamond and silicon carbide in the films changes with TMS flow rates, and diamond/silicon carbide films with gradient composition and smooth transition can be obtained by adjusting the TMS flow rate during deposition process.