Evaluation of Stacked Nanowires Transistors for CMOS: Performance and Technology Opportunities

Stacked-NW FETs pave the way for significant increase in device effective width over FinFET and FDSOI. An increase of performance and/or a decrease of device footprint is expected by using thin and wide NW channels also known as nanosheets or nanoplates. This paper points out Gate Last integration issues of stacked-NWs. Two solutions labeled as NW First and NW Last are presented featuring internal spacer formation. A demonstration of self-aligned gate and spacers is proposed, involving Hydrogen Silsesquioxane (HSQ) lithography through silicon channels.