摘要
本文用微波等离子化学气相沉积系统（MPCVD）在单晶硅衬底上制备多晶金刚石薄膜，反应气体为CH4和H2。利用扫描电镜（SEM）和Raman光谱研究了CH4流量和反应时间对多晶金刚石薄膜形貌和碳结构的影响。结果表明：随着CH4流量的增加，金刚石的成核密度增加，并出现二次形核，金刚石颗粒从单晶逐渐转变为多晶结构。多晶金刚石薄膜的生长过程为：生长初期在单晶硅衬底上形成非晶碳层，金刚石在非晶碳层上成核长大，并伴随着二次成核，最终形成多晶金刚石膜。
Polycrystal diamond flim is prepared on the monocrystal silicon substrate by means of MPCVD. The reaeant gas is CH4 and H2. The influence of CH4 flow and reaction time on the polycrystal diamond film appearance and the carbon structure is studied by means of SEM and Raman. The results shows： with CH4 flow increasing, the diamond nucleationdensity is increased and the second time nucleation appears so that the diamond grains are gradually transfered from the monocrystal structure to the polycrystal structure. The growth process for polycrystal diamond flim is ： at the beginning period of growth, the amorphous carbon layer is formed on the monocrystal silicon substrate and the diamond is nucleating and growing on the amorphous carbon layer, and with the second time nucleation, the polycrystal diamond film is finally formed.
