Gate-All-Around n-MOSFETs With Uniaxial Tensile Strain-Induced Performance Enhancement Scalable to Sub-10-nm Nanowire Diameter

Abstract

The effects of high-level uniaxial tensile strain on the performance of gate-all-around (GAA) Si n-MOSFETs are investigated for nanowire (NW) diameters down to 8 nm. Suspended strained-Si NWs with ~2-GPa uniaxial tension were realized by nanopatterning-induced unilateral relaxation of ultrathin-body 30% strained-Si-directly-on-insulator substrates. Based on these NWs, GAA strained-Si n-MOSFETs were fabricated with a Si thickness of ~8 nm and NW widths in the range of 50 nm down to 8 nm. The GAA strained-Si MOSFETs show excellent subthreshold swing and cutoff behavior, and approximately two times current drive and intrinsic transconductance enhancement compared to similar unstrained Si devices.