Etch characteristics of Si_(1-x)Ge_x films in HNO_3:H_2O:HF  

作　　者：XUE ZhongYing WEI Xing LIU LinJie CHEN Da ZHANG Bo ZHANG Miao WANG Xi 

机构地区：[1]State Key Laboratory of Functional Material for lnformatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China [3]Lanzhou University, Lanzhou 730000, China

出　　处：《Science China(Technological Sciences)》2011年第10期2802-2807,共6页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 61006088);the National Basic Research Program of China (973 Program) (Grant No. 2010CB832906);the Natural Sci-ence Foundation of Shanghai (Grant No. 10ZR1436100)

摘　　要：The etch characteristics of Si_1-xGex films in HNO3:H2O:HF were examined. The etch rate ratio (etch selectivity) between Si_1-xGex and Si escalated with the growth of HNO3 concentration at low concentration level, and when the HNO3 concentration exceeded a critical level the etch selectivity descended with higher HNO3 concentration. The dependence of etch selectivity on the HNO3 concentration was due to the higher critical HNO3 concentration for etching Si than that for etching Si1-xGex. Since the Ge-Ge bond energy was weaker than that of Si-Si and Si-Ge, the Ge atoms were oxidized preferentially once the HNO3 composition exceeded the critical concentration of etching Si1-xGex,which was manifested by the XPS spectra of Si1-xGex etched in HNO3:H2O:HF. When the HNO3 volume rose to another critical value, the significant growth of the Si etch rate low-ered the etch selectivity. Although both the etch rates of Si1-xGex and Si dropped with lower HF concentration, the etch rate ra-tio of Si1-xGex to Si boosted remarkably due to the water-soluble characteristics of GeO2.

关 键 词：Si_（1-x）Ge_x etch rate SELECTIVITY HNO_3 HF 

分 类 号：TN405.98[电子电信—微电子学与固体电子学] X513[环境科学与工程—环境工程]