Preparation technology of diamond film by MPCVD method

With 3 kW/2 450 MHz microwave plasma chemical vapor deposition (MPCVD) system, the growth process of micron diamond film was studied by single factor experimental method with monocrystalline silicon as the substrate. The effects of substrate temperature, cavity pressure and methane volume concentration on the diamond film forming process were investigated and the optimal growth process of micron diamond film was obtained. The results show that the growth rate of diamond film is positively correlated with substrate temperature, cavity pressure and methane volume concentration. There is the best critical value of substrate temperature and cavity pressure for the quality of diamond film. The too high methane volume concentration is not conducive to the formation of diamond phase. The optimum parameters of diamond film growth are determined as follows. The power is 2 200 W, substrate temperature is 850 ℃, cavity pressure is 14 kPa, and methane volume concentration is 2.5%. In this case, growth rate of diamond film is 1.706 μm/h, and diamond phase content is 87.92%.