MPCVD制备大颗粒金刚石形貌的研究  

Study on Morphology of Large-sized Diamond Synthesized by MPCVD

作　　者：吕继磊[1] 满卫东[1] 朱金凤[1] 涂昕[1] 

机构地区：[1]武汉工程大学湖北省等离子体化学与新材料重点实验室,湖北武汉430073

出　　处：《硬质合金》2012年第2期72-79,共8页Cemented Carbides

基　　金：湖北省自然科学基金11104211

摘　　要：利用自制5 kW微波等离子体化学气相沉积(MPCVD)装置,沉积得到了晶粒尺寸达到500μm的大颗粒金刚石。采用抛光后的硅作为基底,CH4和H2为气源,分别研究了基片边缘与中心区域沉积的大颗粒金刚石的表面形貌。通过SEM表征了金刚石的表面形貌,发现基片边缘由于产生放电现象加速了金刚石的沉积,而晶粒之间相互挤压导致了孪晶的产生,影响其生长质量。相反由于中心区域形核密度低,使得晶粒在优先生长的模型下抑制了小晶粒的生长,从而提供更多的能量促进大晶粒的生长,在本实验条件下(100)晶面得到了长大,并获得了表面平整、晶体形貌良好的大颗粒金刚石。最后介绍了国内外合成大颗粒金刚石的研究进展,并对其研究方向做出了展望。Large-sized diamond up to 500 μm was deposited by a home-made microwave plasma assisted CVD reac- tor （2.45 GHz, 5 kW, water-cooled stainless steel chamber）. Polished Si was choosen as the substrate and CH4 and H2were introduced into the experiment. The growth mechanisms of large-sized diamonds deposited on the edge and the center of the substrate were studied respectively. The surface morphology of the grown diamond was characterized by scanning electron microscopy （SEM）. The results show that diamond deposited on the edge of the substrate has a fast growth speed due to the electric discharge phenomena. However, the grain interactions would lead to twinning, which affacts the crystal growth quality. On the contrary, the growth of small grains would be inhibited due to the low nucleation density at the cen- tral area, thus providing more energy to promote grain growth. Under this experimental conditions, （100） surface has been grown up and a high quality large-sized diamond has been deposited on the center of the substrate based on the prior growth model. Finally. the recent nrogress and nrosrpect of large-sized diamond are introduced.

关 键 词：大颗粒 微波等离子体 化学气相沉积 表面形貌 

分 类 号：TQ164[化学工程—高温制品工业]