纳米片状金刚石膜的生长过程

Growth process of nanoflake diamond film

采用微波等离子化学气相沉积系统(MPCVD)在镀钛的单晶硅衬底上制备纳米金刚石薄膜。反应气体为CH4和H2,其流量比为1∶1,微波功率为1 800 W,反应气压为10 kPa。利用扫描电镜(SEM)和Raman光谱分析薄膜的形貌和碳结构。结果表明,纳米金刚石薄膜呈现片状的组织特征,其生长过程为:生长初期在单晶硅衬底上形成由纳米碳颗粒组成的球状碳团簇;随着沉积时间的增加,碳团簇逐渐增大,纳米碳颗粒定向排列或自组装,最终形成片状纳米金刚石膜。

Nanodiamond films were prepared by microwave plasma chemical vapor deposition system（MPCVD） on Ti-coated silicon substrate.The source gases were CH4 and H2,their flow rate was 1∶1.The microwave power was 1 800 W and the reaction pressure was 10 kPa.The microstructure and surface morphology of deposited films were characterized by Raman spectroscope and scanning electron microscope.The results showed that the nanodiamond film was flake textured.The growth process of the nanoflake diamond film could be briefly described as follows： initially spherical clusters composed of nanodiamond particles were formed on substrate,then the flaky texture appeared due to the direction arrangement or self-assembly of nanodiamond particles with the growth of clusters,finally formed the nanoflake diamond film.