目的 研究高质量单晶金刚石外延生长工艺。方法 使用X射线白光形貌束分析了等离子体表面刻蚀处理前后单晶金刚石位错密度的变化，随后使用等离子体刻蚀预处理工艺，通过改变沉积温度研究了其对金刚石质量的影响。为了表征温度对单晶金刚石质量的影响程度，使用拉曼光谱和X射线衍射摇摆曲线等方法分析了单晶金刚石质量以及位错密度的变化情况，进而确定沉积高质量单晶金刚石最佳的沉积温度。结果 X射线白光形貌束结果显示，未进行氢氧等离子体表面刻蚀的籽晶生长之后，由于表面微加工、抛光引入的位错或者微裂纹，导致生长层位错增多；同时，氢氧等离子体表面刻蚀实验结果显示，刻蚀时间并非越长越好；使用刻蚀处理过的单晶金刚石籽晶进行不同温度外延生长实验，籽晶刻蚀后生长的金刚石拉曼峰位均在1332.5 cm?1附近，半高宽为2~3 cm?1之间。在900 ℃沉积之后，X射线摇摆曲线半高宽仅为0.009。结论 使用氢氧微波等离子体刻蚀单晶金刚石，800 ℃刻蚀40 min，可以基本消除因微加工或者抛光引入的位错或者缺陷。经过刻蚀处理的籽晶在900 ℃制备出的单晶金刚石质量最高，位错最少，可以满足高质量单晶金刚石的制备。

The work aims to study the growth technology of high quality single crystal diamond. X-ray white light topography was used to analyze the change of dislocation density in single crystal diamond on the diamond surface before and after etching processing. Then plasma etching pretreatment technology was adopted to study the effects on crystal diamond by changing the deposition temperature. To characterize the influence of temperature on quality of single crystal diamond, Raman spectra and X-ray rocking curves were used to analyze the change of quality and dislocation density of single crystal diamond and determine the best temperature to deposit the high-quality single crystal diamond. X-ray topography images showed that diamond seeds without surface etching by hydrogen and oxygen plasma had more dislocation density in epitaxial layer due to dislocation or micro cracks caused by surface machining or polishing. Meanwhile, the results of surface etching experiments by hydrogen and oxygen plasma showed that longer etching time was not good all the time. When the single crystal diamond seeds after the etching were tested for epitaxial growth at different temperature, the Raman peaks of single crystal diamond grown after etching were all approximately 1332.5 cm?1 and FWHM (Full width half maximum) were all in the range of 2~3 cm?1. After deposition at 900 ℃, FWHM of X-ray rocking curves was as little as 0.009. Etching single crystal diamond by hydrogen and oxygen microwave plasma for 40 min at 800 ℃ could almost eliminate the dislocation or defects introduced by micromachining or polishing. The single crystal diamond prepared by seeds etched at 900 ℃ had the highest quality and the least dislocation and can meet the preparation requirements on high-quality single crystal diamond.