一氧化碳合成金刚石薄膜的形貌和结构分析

利用微波等离子体化学气相沉积(MPCVD)技术，采用偏压增加成核(BEN)、两步生长的方法在一氧化碳(CO)和氢气(H₂)的环境下制备了金刚石薄膜. 利用扫描电子显微镜(SEM)、Raman光谱仪和透射电子显微镜(TEM)对金刚石薄膜的形貌和结构进行了分析. 研究发现金刚石晶粒在第一步成核及生长的过程中产生了层错和孪晶，而在第二步的生长过程中产生的层错和孪晶很少，最终形成的金刚石晶粒外表面比较光滑，包含有近五次对称或者平行的片状的孪晶，并可以观察到少量的位错. 而在样品的边缘由于等离子体的不均匀产生了比样品中心成核密度低的区域. 在这个区域中，发现了一个新的非金刚石的碳结构.

Morphology and structure of the diamond film synthesized from carbon monoxide gas

Diamond film was deposited in CO and H₂ gas mixture by microwave plasma assisted chemical vapor deposition (MPCVD). Bias enhanced nucleation and two-step growth method were employed. Scanning electron microscopy (SEM), Raman spectroscopy and transmission electron microscopy (TEM) were used to characterize the film. It was found that twins and stacking faults were mainly produced at the stages of nucleation and growth. In the second growth stage, the production of defects in the film was reduced considerably, resulting in the final smooth-faceted diamond grains with five-fold symmetry or parallel twins with a small amount of stacking faults. At the edge of the sample, there was a region with low nucleation density, which might be the result of non-uniform plasma existing there. Meanwhile, a non-diamond structure of carbon was found in the edge region.