溅射气压和衬底温度对Si_(1-x)Ge_x薄膜结构和光吸收性能的影响

Effects of Sputtering Pressure and Substrate Temperature on Structure and Optical Absorption Properties of Si_(1-x)Ge_x Thin Films

采用射频磁控溅射法沉积了Si1-xGex薄膜,研究了溅射气压、衬底温度对薄膜结构、厚度、表面形貌、表面成分及光吸收性能的影响。结果表明:薄膜均为微晶结构且相组成不随溅射气压和衬底温度的改变而改变;随着溅射气压升高,薄膜结晶性能降低,升高衬底温度使其结晶性能提高;随气压或温度的升高,薄膜厚度均先增大后减小,在1.0Pa或400℃达到最大值;随温度的升高,薄膜表面团簇现象消失并变得平整致密,气压为8.0Pa时,表面有孔洞和沟道;随气压升高,薄膜中锗含量降低,光吸收强度减小,光学带隙增大;衬底温度的变化对光学带隙影响不大。

Si1-xGex thin film was deposited by radio frequency magnetron sputtering method.The effects of sputtering pressure and substrate temperature on the structure,thickness,surface morphology,composition and optical absorption properties of the films were studied.The results show that phase composition of the film was microcrystalline structure,and it would not change with change of the sputtering pressure and substrate temperature.Crystal properties lowered with increase of the pressure,and improved with increase of the temperature.Thin film thickness first increases and then decreases with increase the pressure or temperature,and reached the maximum at 1.0 Pa or 400 ℃.Cluster disappeared and the thin film surface became smooth with increase of the temperature,but the surface had holes and channel when the pressure was 8.0 Pa.Ge content in thin film decreased with increase of pressure,and optical absorption intensities decreased,while the optical bandgap increased;the substrate temperature had little effect on the optical bandgap of film.