A new liner stressor (GeTe) featuring stress enhancement due to very large phase-change induced volume contraction for p-channel FinFETs

We report the first demonstration of a novel GeTe liner stressor which exhibits very large volume contraction during phase-change, and its integration in p-channel FinFETs for strain engineering. Conformally grown GeTe liner with different thicknesses was formed on FinFETs with ultra-scaled gate length L_G down to ~3 nm. When GeTe changes phase from amorphous (α-GeTe) to crystalline state (c-GeTe), GeTe liner contracts and compresses the Si source/drain region in the fin, leading to very high channel stress. Significant drive current I_Dsat enhancement of 69% and 106% were observed for FinFETs with 30 nm and 50 nm c-GeTe liner stressor over the control devices, respectively.