VHF-PECVD法制备μc-SiGe薄膜的研究

Preparation of μc-SiGe thin films by VHF-PECVD

分别以Si2H6和GeH4及SiH4和GeH4两种组合气体为源气体,用甚高频等离子增强化学气相沉积(VHF-PECVD)制备μc-SiGe薄膜,用Raman散射光谱和原子力显微镜(AFM)对薄膜的结构进行研究。结果表明:与SiH4和GeH4制备的薄膜系列相比,Si2H6和GeH4制备的薄膜中Ge的融入速率相对较慢;用Si2H6和GeH4制备的μc-SiGe薄膜,随着GeH4浓度的增加,薄膜结构始终保持一定的有序度;随着H2稀释率、辉光功率的增大,薄膜结构趋于有序。

A series of μc-SiGe thin films are prepared with Si 2H 6＋GeH 4 and SiH 4＋GeH 4 as source gases respectively by very-high frequency plasma enhanced chemical vapor deposition（VHF-PECVD） technique.Structure of films is analyzed by micro-Raman spectroscopy and atomic force microscopy（AFM）.The experimental results show that the films deposited with Si 2H 6＋GeH 4 present a slower Ge incorporation rate in the films than those deposited with SiH 4＋GeH 4,and also the structure shows almost no order deteriorating with the increasing of Ge content.The structure of the films changes from amorphous state to microcrystalline state with the increasing of H 2 dilution and plasma power.