圆柱形和椭球形谐振腔式MPCVD装置中微波等离子体分布特征的数值模拟与比较

Simulation and Comparison of Microwave Plasma in Cylindrical and Ellipsoidal Microwave Plasma Chemical Vapor Deposition Cavity

在使用简化的等离子体放电模型的基础上,模拟了圆柱形和椭球形谐振腔式微波等离子体金刚石膜沉积设备中,不同金刚石膜生长条件下微波等离子体的分布状态。对不同的微波输入功率、不同气体压力条件下,两种谐振腔式设备中形成的等离子体分布的变化规律进行了模拟。模拟结果表明,椭球形谐振腔的质量因子要高于圆柱形谐振腔;并且,椭球形谐振腔更适合用于高功率、高压力的金刚石膜沉积环境。这意味着,使用椭球形谐振腔,可获得更高的金刚石膜生长速率。

By using a tractable plasma description, distribution of H2 microwave plasma under various operating conditions for deposition of diamond films in a cylindrical and an ellipsoidal microwaw, plasma chemical vapor deposition cavity has been simulated. Especially, dependence of plasma distribution in the two kinds of cavities on the microwave input power and gas pressure has been studied. The simulation results show that the quality factor of ellipsoidal cavity is higher than that of the cylindrical cavity, and diamond films could be deposited with higher input power and at higher pressure in the ellipsoidal cavity system. This means that a higher growth rate of diamond films could be realized with an ellipsoidal cavity apparatus.