EACVD沉积金刚石过程中气相化学研究

利用热阴极直流等离子体化学气相沉积技术分别在ＣＨ４－Ｈ２和Ｃ２Ｈ５ＯＨ－Ｈ２两种不同的工作环境中沉积金刚石膜，同时利用发射光谱对等离子体气相环境进行了原位诊断。在ＣＨ４－Ｈ２和Ｃ２Ｈ５ＯＨ－Ｈ２两种体系中，探测到Ｈ原子和ＣＨ、ＣＨ＾＋、Ｃ２等多种碳氢粒子，发现ＣＨ和ＣＨ＾＋有益于金刚石生长，而Ｃ２是非金刚石相的生长基团。与ＣＨ４－Ｈ２体系所不同的是，在Ｃ２Ｈ５ＯＨ－Ｈ２体系中，还产生了ＣＨＯ、ＣＨ

Gas phase chemistry during electron assisted chemical vapor eposition (EACVD) of dianond films

Diamond films were deposited in electron assisted chemical vapor deposition (EACVD) reactor using two source mixtures of CH4-H2 and C2H5OH-H2, respectively. The plasma gas composition during diamond growing was investigated in situ using optical emission spectroscopy(OES). In two cases of C2H2OH-H2 and CH4-H2 plasma, it was shown that CH and CH were all important precursor species in the diamond deposition reaction while the yields of poor diamond films corresponded to the presence of the C2 emission line. The difference between these two cases was that some oxygen-containing species (CH2O, CHO and O2) were detected in the C2mOH-H2 plasma. The presence of these products may maintain the quality of the deposited diamond films while increasing carbon source concentration, and the growth rate was thus enhanced. These results imply that the increase in the growth rate of diamond film using C2H5OH-H2 mixture is primarily due to a change in gas phase environment.