Fabrication of Strained Silicon on Insulator (SSOI) by Direct Wafer Bonding Using Thin Relaxed SiGe Film as Virtual Substrate

Abstract

ABSTRACTNMOS devices have been successfully fabricated on SSOI wafers. The SSOI wafer fabrication is by direct wafer bonding and wafer transfer by splitting of the strained Si on thin SiGe virtual substrate to an oxidized wafer. The thin SiGe virtual substrate is fabricated by strained SiGe deposition, H2+ implantation, and SiGe lattice relaxation anneal. This relaxation process creates a confined defect zone at the SiGe to Si substrate interface that ensures low defect strained Si growth. 10 μm by 10 μm NMOS SSOI devices show an improvement of 100% in drive current and 115% in transconductance. A near ideal subthreshold swing was observed on NMOS devices with channel length as short as 0.1 μm.