High Performance 4.5-nm-Thick Compressively-Strained Ge-on-Insulator pMOSFETs Fabricated by Ge Condensation with Optimized Temperature Control

We report high performance extremely-thin-body (ETB) Ge-on-Insulator (GOI) pMOSFETs fabricated by a new Ge condensation process with minimized temperature cycles and slow cooling-down rate. This new condensation process effectively suppresses strain relaxation during Ge condensation and creates high compressive strain. By combining the highly-strained GOI substrates with a digital etching process, we successfully realized 4.5-nm-thick strained-GOI pMOSFETs with excellent GOI thickness uniformity. The MOSFETs exhibit highest hole mobility of 138 cm(2)/Vs in GOI thickness less than 5 nm and the hole mobility enhancement of 2.0 over that of best performance GOI pMOSFETs in this thickness range.