类金刚石薄膜的慢正电子分析

采用射频－直流等离子化学气相沉积法制备类金刚石薄膜，用慢正电子湮灭技术研究了类金刚石薄膜中缺陷的深度分布，并系统研究了工艺参数对类金刚石薄膜中缺陷浓度的影响．实验结果表明，单晶Si衬底具有很高的缺陷浓度，类金刚石薄膜中的缺陷浓度较低．且缺陷均匀分布，薄膜表面存在一缺陷浓度较高的薄层，而膜一基之间存在一很宽的界面层，界面层内缺陷浓度随离衬底表面距离的增加而线性降低，到达薄膜心部后，缺陷浓度趋于稳定．类金刚石薄膜的缺陷浓度和膜－基界面层宽度都随负偏压的升高呈先降低、后增加再降低的变化趋势．薄膜中的缺陷浓度随混合气体中C₂H₂含量的升高而单调增大，但C₂H₂含量对界面层宽度没有影响．

Diamond-Like Carbon Films by Low Energy Positron Beam

Diamond-Like Carbon films were deposited on Si substrate from the mixture of C2H2 and Ar by r.f.-d.c. plasma enhanced chemical vapor deposition. The influence of deposition process on the density and distribution of void in Diamond-Like Carbon films was systematically studied by low energy positron beam. The results indicate that the density of void in Si substrate is the highest.A constant distribution of void was observed through the films, the density of void is lower, but the density of void in the surface layer is higher. The density of void starts to increase neal the interface and finally reaches the value of Si substrate. With the increasing of bias, the density of void in the films and the depth of interface decrease at first, then increase, and then decrease. The density of void in the films increases monotonous with the increasing of C2H2 percentage in the feed gas.