Numerical simulation and experimental study of a novel high-power microwave plasma CVD reactor for diamond films deposition

According to the demand of high-power MPCVD device, a novel model of high-power MPCVD reactor for diamond films deposition was introduced. HFSS was preliminary used for size optimization in all parts of the device. COMSOL was used to simulate the electric filed and the plasma distribution when the gas was dissociated under high pressure and power, COMSOL was also used to verify the in and out way of the gas. The new reactor with the proposed geometry was constructed. The experiment of large-area diamond film was deposited under high pressure and power with the new reactor. The simulated and experimental results show that the reactor exhibit excellent focusing capability after the structure optimization. Meanwhile the electric field strength is larger than the similar unit reported by others. The plasma and reactant gas were evenly distributed only on the substrate. The plasma is isolated with the quartz window by the middle cavity, which effectively protects the quartz window from the etching of plasma. By using our new reactor, the deposition of high quality and large-area diamond films with high growth rate under high power and gas pressure can be obtained. ©, 2015, Rengong Jingti Xuebao/Journal of Synthetic Crystals. All right reserved.