H2-O2混合气氛刻蚀制备金刚石纳米晶薄膜

提供了在镜面抛光Si衬底上沉积平滑的纳米金刚石（NCD）薄膜的方法。采用微波等离子体化学气相沉积（CVD）系统，利用H2、CH4和O2为前驱气体，在镜面抛光的Si基片上制备了直径为5cm的NCD薄膜，用扫描电镜（SME）和共焦显微拉曼光谱分析其表面形貌和结构特点。分析表明，利用这种方法可以制备出高sp^3含量的NCD薄膜。通过与沉积时间加长而沉积条件相同情况下合成的金刚石微晶薄膜形貌相对比，分析了H2-O2混合气氛刻蚀制备NCD薄膜的机理。分析表明，基底的平滑度对O2的刻蚀作用起到重要的影响；在平滑的基底上，含量较少的O2的刻蚀作用也很明显；随着基底的平滑度下降，混合气氛中O2的刻蚀作用逐渐减弱。

Fabrication of Nano-crystal Diamong Film Etched by Mixture Gases of H2-O2

A plain nano-crystal diamond(NCD) film with diameter of 5 cm has been prepared on commercial mirror-polished Si substrate by microwave plasma chemical vapor deposition(CVD) system in mixture gases of H_2,CH_4 and O_2.According to the observation of SEM picture and micro-Raman spectra the morphology and structure are analyzed.It is found that the film with high concentration of sp~(3+) has uniform crystal particle size,and the average size of diamond particles is about 150 nm.The etching mechanism by the mixture gases of H_2-O_2 is discussed through compared with SEM picture of micro-crystal diamond film deposited in the same condition and longer time.It is shown that the smooth substrate is important for the etching effect of O_2.O_2 with lower content compared with H_2 shows key effect during the beginning period of diamond film deposition.The influence gradually decreases when the grow substrate becomes rough.This work might benefit to the applications of diamond film such as surface acoustic wave device or infrared transmission coating film.