STUDY ON P-TYPE SURFACE CONDUCTIVITY OF CVD PLASMA DIAMOND

1. 对现有的高分辨率卢瑟福后向散射系统进行了改进，用于弹性后坐力探测。在目标和磁谱仪之间安装了一个静电四极透镜来修正所谓的运动展宽。这种校正对于在氢气深度剖面中获得高深度分辨率至关重要。在分析磁铁和位置敏感探测器之间还安装了一个静电偏转板，以抑制分散的探针离子。设计了一种多参数数据采集系统，用于从暗噪声中提取信号。利用研制的高分辨率ERD系统，研究了CVD金刚石薄膜中氢剖面的深度分辨率和检出限。结果表明，深度分辨率为0.2 nm，检出限约为0.5 at。%。采用高分辨率ERD测量了CVD金刚石膜中的氢深度分布。氢谱在表面有一个尖峰。这个峰有一个小的尾部，朝向更大的深度，表明一些氢原子被纳入了地下区域。未掺杂和掺杂b的金刚石薄膜的氢谱没有差异。用酸溶液除去表面氢后，用氢等离子体在800℃下对金刚石进行再氢化处理。再氢化后的金刚石膜表现出与生长后的金刚石膜几乎相同的轮廓。

1. We have modified existing highresolution Rutherford backscattering system for elastic recoil detection (ERD). An electro-static quadrupole lens was installed between the target and the magnetic spectrometer for correction of so-called kinematic broadening. This correction is essential to get high depth resolution in hydrogen depth profiling. An electrostatic deflector was also installed between the analyzing magnet and a position sensitive detector to reject scattered probe ions. A multi-parameter data acquisition system was developed to select signals from dark noise. Using the developed high-resolution ERD system, the depth resolution and the detection limit for hydrogen profiling in CVD diamond films were examined. It was shown that the depth resolution of 0.2 nm and the detection limit of about 0.5 at.% were achieved.2. The hydrogen depth profiles in CVD diamond films were measured with high-resolution ERD. The hydrogen profile showed a sharp peak at the surface. The peak had a small tail toward larger depth, showing that some hydrogen atoms are incorporated in the subsurface region. There was no difference in the hydrogen profile between the undoped and B-doped diamond films. After surface hydrogen was removed by an acid solution, the diamond was rehydrogenated by a hydrogen plasma at 800℃. The rehydrogenated diamond film shows almost the same profile as the as-grown film.