RF-PECVD法制备a-Si1-x Cx:H薄膜的光学性能研究

摘要

以SiH4和CH4为源气体,采用射频等离子增强化学气相沉积(RF-PECVD)方法,通过改变CH4/SiH4流量比和射频功率制备非化学计量比氢化非晶碳化硅(a-Si1-x Cx:H)薄膜.采用傅里叶转换红外光谱(FTIR)和紫外-可见(UV-Vis)光谱等测试手段,对薄膜的成键情况及其对光学带隙的影响进行了研究分析.结果表明,Si-C键的强度和光学带隙随着CH4/SiH4 流量比的增加而增大;但是,随着射频功率的增加,a-Si1-x C4:H薄膜的光学带隙反而略有减小.%Non-stoichiometry hydrogenated amorphous silicon carbide( a-Si1-xCx :H)thin films were deposited by radio frequency plasma enhanced chemical vapor deposition(RF-PECVD) using SiH4 and CH4 as source gases at different CH4/SiH4 flow ratios and radio-frequency powers,respectively. The chemical bonding modes among component atoms in the films and its impact on the optical band gap were investigated by Fourier transform infrared spectroscopy (FTIR) and Ultraviolet-Visible (UV-Vis) spectroscopy. The results indicate that, the strength of Si-C bond and the optical band gap of the a-Si1-x Cx :H thin films grow with the increase of CH4/SiH4 flow ratios. However, with the increase of radio-frequency power,the optical band gap of the a-Si1-xCx :H thin films decreases slightly.