Asymetrically strained high performance Germanium gate-all-around nanowire p-FETs featuring 3.5 nm wire width and contractible phase change liner stressor (Ge2Sb2Te5)

We report the first demonstration of Ge gate-all-around (GAA) nanowire (NW) p-FETs integrated with a contractible liner stressor. High performance GAA NW p-FET featuring the smallest wire width W_NW of ~3.5 nm was fabricated. Peak intrinsic transconductance G_m of 581 μS/μm and SS of 125 mV/dec. were demonstrated. When the Ge NW p-FETs were integrated with the phase change material Ge₂Sb₂Te₅ (GST) as a liner stressor, high asymmetric strain was induced in the channel to boost the hole mobility, leading to ~95% intrinsic G_{m, lin} and ~34% extrinsic G_{m, sat} enhancement. Simulations show good scalability of strain due to GST liner stressor and its great potential for hole mobility enhancement.