沉积温度对微晶硅薄膜结构特性的影响

采用PECVD技术，在玻璃衬底上沉积μc-Si:H薄膜. 用拉曼光谱、SEM和UV分光光度计对不同沉积温度下沉积的薄膜的结构特性进行分析. 研究发现：沉积温度较低时，随着沉积温度的升高，薄膜的晶化率增加；当沉积温度超过某一温度值时，随着温度的进一步升高，薄膜的晶化率降低. 这时，表面反应由表面扩散限制转变为流量控制. 该温度值随着硅烷含量的降低而降低. 关键词： 氢化微晶硅薄膜 拉曼散射谱 晶化率 UV分光光度计

The influence of deposition temperature on the structure of microcrystalline silicon film

Undoped hydrogenated silicon films have been prepared from a gas mixture of silane and hydrogen, at deposition temperature varying from 200—450℃ in an ultrahigh vacuum system using RFPECVD technique. Raman scattering, SEM and UV spectrophotometer are used to analyse the structure changes of microcrystalline silicon films throughout the deposition temperature range. Results show that at lower deposition temperature, the crystalline volume fraction of μc-Si:H films increased with the increasing of deposition temperature. Exceeding a certain temperature, the crystalline volume fraction decreased with further increasing of deposition temperature. This is attributed to a change in the dominant film growth process from surface-diffusion-limited at low deposition temperatures to flux-limited at higher deposition temperatures.