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

fYear

1998

fDate

5-8 Oct. 1998

Firstpage

141

Lastpage

142

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;

fLanguage

English

Publisher

ieee

Conference_Titel

SOI Conference, 1998. Proceedings., 1998 IEEE International

Conference_Location

Stuart, FL, USA

ISSN

1078-621X

Print_ISBN

0-7803-4500-2

Type

conf

DOI

10.1109/SOI.1998.723151

Filename

723151