微晶硅薄膜的表面粗糙度及其生长机制的X射线掠角反射研究

Studies on surface roughness and growth mechanisms of microcrystalline silicon films by grazing incidence X-ray reflectivity

采用等离子体增强化学气相沉积技术沉积一系列处于不同生长阶段的微晶硅薄膜.通过同步辐射X射线掠角反射技术研究微晶硅薄膜的表面粗糙度随时间等的演化,探讨微晶硅薄膜的生长动力学过程及其生长机制.研究结果表明,在衬底温度为200℃,电极间距为2cm,沉积气压为6.66×102Pa,射频功率密度为0.22W/cm2,氢稀释度分别为99%和98%的沉积条件下,在玻璃衬底上生长的微晶硅薄膜生长指数β分别为0.21±0.01和0.24±0.01.根据KPZ模型,微晶硅薄膜的生长机制为有限扩散生长.

The microcrystalline silicon films at different growth stages were deposited by plasma-enhanced chemical vapor deposition （PECVD）. The reflectivity of grazing incidence X-ray from synchrotron radiation has been applied to investigate the evolution of surface roughness of these thin films. By study of surface morphology of micmcrystalline silicon （μc-Si ： H）, we understand their growth kinetics and growth mechanism. The results show that the growth exponent β is 0.21 ± 0.01 and 0.24 ± 0.01 for μc-Si： H films deposited on glass substrate at fixed substrate temperature, Under the following condition of electrode distance, pressure, rf power density, H2 dilutied at 200 ℃ to be 2 cm, 6.66 ×10^2 Pa and 0.22 W/cm^2, 99% and 98%, respectively. According to the KPZ model in the PECVD case the growth mechanism of the μc-Si：H films is a finite diffusion growth.