【摘要】 采用微波等离子体化学气相沉积(MPCVD)技术,在甲烷和氢气的混合气体中,通过掺入微量氮气的方法,合成了掺氮金刚石薄膜.利用扫描电子显微镜、拉曼光谱和透射电子显微镜对薄膜的形貌和结构进行了表征.研究结果表明:处于基片中心位置的薄膜具有比较高的成核密度,成核密度高达4.8×108cm-2,并且具有〈001〉的择优取向,晶粒呈立方金刚石特征,但沿{111}晶面生长时存在大量层错.处于基片边缘的薄膜成核密度较低,晶粒为6H型多型金刚石结构,而且多型金刚石的出现,导致金刚石孪晶关系的变化.此外,根据薄膜的生长速率,探讨了MPCVD过程中掺氮对薄膜生长行为的影响.更多还原

【Abstract】 Diamond film was deposited in CH4 and H-2 gas mixture with a small amount of N-2 by microwave plasma assisted chemical vapor deposition(MPCVD).Scanning electron microscopy,Raman spectroscopy and transmission electron microscopy were applied to characterize the film.The results showed that the growth of grains are different the central region and the edge.In the central region,diamond grains nucleated with a density as high as 4.8×108 cm-2 and were preferential in 〈001〉 orientation.The inner grains formed an area without stacking faults,which was surrounded by a rim with a high density of stacking faults.A growth model was suggested to interpret the morphological feature and the behavior of preferential growth.At the edge,the grains were identified to be 6H polytypes of diamond and a new twin relationship of grains was found.Besides,the effect of the N dopant on the growth behavior of the diamond film deposited by MPCVD was discussed in connection with the growth rate of the film.更多还原