纳米硅薄膜结构特性研究

Study on Structural Properties of Nanocrystalline Silicon Films

在电容式耦合等离子体化学气相沉积系统中，使用高氢稀释硅烷为反应气体制备出了晶粒尺寸为２～１０ｎｍ的纳米微晶相结构的硅薄膜，使用高分辨电子显微镜（ＨＲＥＭ），Ｘ射线衍射谱（ＸＲＤ），Ｘ射线光电子能谱（ＸＰＳ）和红外光谱（ＩＲ）等结构分析手段检测了其结构特征．结果表明，纳米硅薄膜的晶格结构为畸变的金刚石结构．Ｘ射线衍射谱表明除了Ｓｉ（１１１）的２θ＝２８．５°和Ｓｉ（２２０）的２θ＝４７．３°处的衍射峰外，在２θ＝３２．５°处存在着一个强的异常峰．ＨＲＥＭ结果表明存在新的Ｓｉ结晶学结构与ＸＲＤ异常峰相关联．研究结果还表明随着功率增加，Ｓｉ薄膜网络结构的晶态成分增加．

Abstract Nanocrystalline silicon(nc-Si: H) films with an average grain size ranging from 2nm to 10nm were prepared by a plasma glow discharge CVD method. X-ray diffraction,High Resolution Electron Microscopy (HREM) were used to elucidate the structural nature in the nanocrystalline silicon films. The results show that the crystal lattice of the nanocrystalline silicon is a deformed diamond lattice. In the observed X-ray diffraction,there is an anomalous peak at 2θ=32. 5°of St besides the normal peaks at 2θ=28. 5°of Si(111) and 2θ=47. 3°of Si(220). The results of HREM show that a new crystallographic structure of silicon is found. The crystalline fraction of the network structure of silicon films increases with the increasing of RF power.EEACC: 0520, 2520F