本工作采用蒙特卡罗(Monte Carlo)方法,对以CH4/H2为源气体的电子助进化学气相沉积(EACVD)金刚石薄膜的气相动力学过程进行了模拟。提出了衬底温度的空间梯度变化模型,研究了衬底温度对EACVD气相过程中的电子群行为以及H2和CH4分解过程的影响。结果表明:电子平均温度随着衬底温度的升高而升高;当气压较低时,分解得到的成膜关键粒子H、CH3数量随衬底温度的增大而减少;而当气压较高时,H、CH3数目随衬底温度的增大而增大;衬底温度主要改变了衬底表面附近的化学反应动力学过程,从而对薄膜质量产生了决定性的影响。
The gas phase kinetics process of the diamond film grown by electron-assisted chemical vapor deposition (EACVD) using CH4/H2 mixture was studied by Monte Carlo simulation method. The effect of substrate temperature on the behavior of electrons and dissociation process of H2 and CH4 in EACVD were investigated. The results show that the average energy of electrons increases with increasing of substrate temperature. The number of the key radicals H, CH3 decreases with increasing of substrate temperature in the lower gas pressure range, while it increases in the higher gas pressure range. The substrate temperature just affects the gas phase reaction process near the substrate, which suggests that the strong dependence on substrate temperature of the quality of diamond film is attributed to the change of phase process near the substrate brought by substrate temperature.