STUDY ON P-TYPE SURFACE CONDUCTIVITY OF CVD PLASMA DIAMOND

1.对现有的用于弹性反冲探测的高分辨率卢瑟福背散射系统进行了改进。在靶体和磁光谱仪之间安装了一个静电四极透镜，用于校正所谓的运动展宽。为了在氢深度剖面中获得高深度分辨率，这种校正是必不可少的。在分析磁铁和位置灵敏探测器之间还安装了静电偏转器，以抑制散射探针离子。为了从暗噪声中提取信号，研制了一种多参数数据采集系统。利用研制的高分辨率ERD系统，研究了CVD金刚石膜氢轮廓的深度分辨率和检测下限。结果表明，该方法的深度分辨率为0.2 nm，检测下限约为0.5at.%。用高分辨率ERD测量了CVD金刚石膜中氢的深度分布。氢气分布在表面有一个尖锐的峰。峰有一条小尾巴朝向更大的深度，表明一些氢原子被结合在次表层区域。未掺杂和B掺杂的金刚石薄膜的氢分布没有差别。在酸性溶液中去除表面氢后，用800℃的氢等离子体对金刚石进行二次氢化。二次氢化金刚石膜表现出与原生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.