摘要
采用热丝化学气相沉积技术制备了一系列处于不同生长阶段的薄膜样品 ,用原子力显微镜系统地研究生长在单晶硅衬底和玻璃衬底上薄膜表面形貌的演化 .按照分形理论分析得到 :在玻璃衬底上的硅薄膜以零扩散随机生长模式生长 ;而在单晶硅衬底上 ,薄膜早期以有限扩散生长模式生长 ,当膜厚超过某一临界厚度时转变为零扩散随机生长模式 .岛面密度与膜厚的依赖关系表明 ,在临界厚度时硅衬底和玻璃衬底上的岛面密度均出现了极大值 .Raman谱的测量证实 ,玻璃衬底上薄膜临界厚度与非晶 微晶相变之间存在密切的关系 .不同的衬底材料直接影响反应基元的表面扩散能力 ,从而造成薄膜早期生长模式的差异 .
Microcrystalline silicon thin films at different growth stages were prepared by hot wire chemical vapor deposition. Atomic force microscopy has been applied to investigate the evolution of surface topography of these films. According to the fractal analysis I it was found that, the growth of Si film deposited on glass substrate is the zero-diffused stochastic deposition; while for the film on Si substrate, it is the finite diffused deposition on the initial growth stage, and transforms to the zero-diffused stochastic deposition when the film thickness reaches a certain value. The film thickness dependence of island density shows that a maximum of island density appears at the critical film thickness for both substrates. The data of Raman spectra approve that, on the glass substrate, the a-Si: H/mu c-Si:H transition is related to the critical film thickness. Different substrate materials directly affect the surface diffusion ability of radicals, resulting in the difference of growth modes on the earlier growth stage.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第4期1890-1894,共5页
Acta Physica Sinica
基金
国家重点基础研究发展规划 (批准号 :G2 0 0 0 0 2 82 0 8)
中国科学院研究生院院长基金 (批准号 :yzjj2 0 0 3 0 2_y10 2 6)资助的课题~~
关键词
生长机制
微晶硅薄膜
表面形貌
热丝化学气相沉积
growth mechanism
microcrystalline silicon thin film
surface morphology
hot wire chemical vapor deposition
