电子助进化学气相沉积金刚石中发射光谱的蒙特卡罗模拟

Monte Carlo simulation of optical emission spectra in electron assisted chemical vapor deposition of diamond

采用蒙特卡罗方法 ,对源料气体为CH4 H2 混合气的电子助进化学气相沉积 (EACVD)中的氢原子 (H)、碳原子(C)以及CH基团的发射过程进行了模拟 .研究了CH4 浓度、反应室气压和衬底偏压等工艺参数对发射光谱及成膜的影响 .研究发现 ,CH基团可能是有利于金刚石薄膜生长的活性基团 ,而碳原子不是 ;偏压的升高可提高电子平均温度及衬底表面附近氢原子的相对浓度 ;通过氢原子谱线可测定电子平均温度并找到最佳成膜实验条件 .该结果对EACVD生长金刚石薄膜过程中实时监测电子平均温度 ,有效控制工艺条件 ,生长出高质量的金刚石薄膜具有重要的意义 .

The optical emission spectra of atomic hydrogen, atomic carbon and radical CH in electron assisted chemical vapor deposition (EACVD) were studied by using the Monte Carlo simulation when CH4/H-2 gas mixture was used as the input gases. Effects of the experimental parameters on emission spectra and synthesis of diamond films were investigated. The results obtained suggested that the CH radicals should be considered as a precursor species for diamond deposition but atomic carbon C is not. The diamond growth rate may be enhanced by the substrate bias due to the changes of atomic hydrogen concentration and the increase of mean electron temperature. A method of determining the mean temperature of electron was gained by using atomic hydrogen emission fine, and the optimum experimental condition for diamond deposition was also obtained. These results are of great importance for depositing high-quality diamond films by controlling the conditions of technology efficiently.