Title :
Defect reduction of bonded SOI wafers by post anneal process in H/sub 2/ ambient
Author :
Tate, N. ; Furihata, J. ; Aga, H. ; Mitani, K.
Author_Institution :
Isobe R&D Center, Shin-Etsu Handotai Co. Ltd., Gunma, Japan
Abstract :
Bonded SOI is known to have at least two kinds of intrinsic defects. One is the "HF defect", most likely caused by "as grown defects" when CZ wafers are used for a top silicon layer. The second is the "Secco (etch) defect", which seems to be due to the final polishing process of SOI fabrication. This defect can be reduced by annealing in inert gas ambient (Aga et al. 1997). If the HF defect is genuinely related to as grown defects in CZ, one way to avoid this defect is to use an epitaxial wafer for the top layer. Another is a high temperature post-anneal after the SOI fabrication process. The latter approach may allow us to use current standard CZ as top Si. A rapid thermal process (RTP) hydrogen (H/sub 2/) anneal was investigated and it was found that anneal temperatures >1150/spl deg/C were effective for reduction of both types of defects.
Keywords :
crystal growth from melt; etching; hydrogen; integrated circuit reliability; integrated circuit yield; polishing; rapid thermal annealing; silicon-on-insulator; wafer bonding; 1150 C; CZ wafer top silicon layer; H/sub 2/; H/sub 2/ RTA; H/sub 2/ anneal ambient; HF defect; SOI fabrication; SOI fabrication process; Secco etch defect; Si; Si-SiO/sub 2/; anneal temperature; as grown defects; bonded SOI intrinsic defects; bonded SOI wafers; defect reduction; epitaxial wafer top layer; final polishing process; high temperature post-anneal; inert gas ambient anneal; post anneal process; rapid thermal process H/sub 2/ anneal; standard CZ top Si; Annealing; Etching; Hafnium; Hydrogen; Wafer bonding;
Conference_Titel :
SOI Conference, 1998. Proceedings., 1998 IEEE International
Conference_Location :
Stuart, FL, USA
Print_ISBN :
0-7803-4500-2
DOI :
10.1109/SOI.1998.723151
