高温高压与CVD金刚石单晶衬底质量对比研究

本文通过高分辨X射线衍射(HRXRD)、激光拉曼光谱(Raman)、晶格畸变检测等测试分析方法对多组高温高压(HTHP) Ⅰb、HTHP Ⅱa和化学气相沉积(CVD)型(100)面金刚石单晶样品进行对比研究。HRXRD和Raman的检测结果均表明HTHP Ⅱa型金刚石单晶的结晶质量接近天然金刚石,其XRD摇摆曲线半峰全宽和Raman半峰全宽分别为0.015°~0.018° 和1.45~1.85 cm^-1。晶格畸变检测仪的检测结果表明,HTHP Ⅱa型金刚石单晶的应力分布主要有两种:一种几乎无明显应力分布,另一种沿<110>方向呈对称的放射状分布,其他区域无晶格畸变。HTHP Ⅰb和CVD型金刚石单晶应力分布均相对分散,晶格畸变复杂,与其HRXRD和Raman的检测结果相符。进一步利用等离子体刻蚀法对三种类型金刚石单晶(100)面位错缺陷进行对比分析,结果表明,HTHP Ⅱa型金刚石位错密度为三者中最低,仅为1×10³ cm^-2。本研究为制备高质量大尺寸CVD金刚石单晶的衬底选择提供了实验依据。

Comparative Study on the Quality of HTHP and CVD Single Crystal Diamond Substrates

The comparative study of high temperature and high pressure (HTHP) and chemical vapor deposition (CVD) single crystal diamonds was carried out. HTHP Ⅰb, HTHP Ⅱa, and CVD (100) single crystal diamonds were investigated by HRXRD, Raman and lattice distortion detector. The results of HRXRD and Raman demonstrate that the crystal quality of HTHP Ⅱa single crystal diamond is close to that of natural diamond. The full width at half maximum of rocking curve and Raman are respectively 0.015° to 0.018° and 1.45 cm^-1 to 1.85 cm^-1. The optical birefringence images measured by lattice distortion detector show that there are two kinds of stress-induced birefringence distribution in HTHP Ⅱa single crystal diamond, one is not obvious, the other is symmetrically radiated along the direction of <110>, and there is no lattice distortion in other regions. The strain structures of HTHP Ⅰb and CVD (100) single crystal diamond are relatively dispersed with complex lattice distortion. Furthermore, the defects of (100) plane of three types of single crystal diamond were analyzed by plasma etching method. The results show that the dislocation density of HTHP Ⅱa diamond is the lowest among the three types, which is only 1×10³ cm^-2. The research work provides experiment support for selecting the substrate to prepare high-quality and large-size CVD single crystal diamond.