Fabrication of strained Ge film using a thin SiGe virtual substrate  

作　　者：郭磊 赵硕 王敬 刘志弘 许军 

机构地区：[1]Tsinghua National Laboratory for Information Science and Technology,Institute of Microelectronics,Tsinghua University

出　　处：《Journal of Semiconductors》2009年第9期16-20,共5页半导体学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Nos.60636010,60820106001)

摘　　要：This paper describes a method using both reduced pressure chemical vapor deposition （RPCVD） and ultrahigh vacuum chemical vapor deposition （UHVCVD） to grow a thin compressively strained Ge film. As the first step, low temperature RPCVD was used to grow a fully relaxed SiGe virtual substrate layer at 500 ℃ with a thickness of 135 nm, surface roughness of 0.3 nm, and Ge content of 77%. Then, low temperature UHVCVD was used to grow a high quality strained pure Ge film on the SiGe virtual substrate at 300 ℃ with a thickness of 9 nm, surface roughness of 0.4 nm, and threading dislocation density of - 10^5 cm^-2. Finally, a very thin strained Si layer of 1.5-2 nm thickness was grown on the Ge layer at 550 ℃ for the purpose of passivation and protection. The whole epitaxial layer thickness is less than 150 nm. Due to the low growth temperature, the two-dimensional layer-by-layer growth mode dominates during the epitaxial process, which is a key factor for the growth of high quality strained Ge films.This paper describes a method using both reduced pressure chemical vapor deposition （RPCVD） and ultrahigh vacuum chemical vapor deposition （UHVCVD） to grow a thin compressively strained Ge film. As the first step, low temperature RPCVD was used to grow a fully relaxed SiGe virtual substrate layer at 500 ℃ with a thickness of 135 nm, surface roughness of 0.3 nm, and Ge content of 77%. Then, low temperature UHVCVD was used to grow a high quality strained pure Ge film on the SiGe virtual substrate at 300 ℃ with a thickness of 9 nm, surface roughness of 0.4 nm, and threading dislocation density of - 10^5 cm^-2. Finally, a very thin strained Si layer of 1.5-2 nm thickness was grown on the Ge layer at 550 ℃ for the purpose of passivation and protection. The whole epitaxial layer thickness is less than 150 nm. Due to the low growth temperature, the two-dimensional layer-by-layer growth mode dominates during the epitaxial process, which is a key factor for the growth of high quality strained Ge films.

关 键 词：strained Ge SiGe virtual substrate RPCVD UHVCVD 

分 类 号：TN304[电子电信—物理电子学]