Cryogenic operation of Ω-gate p-type SiGe-on-insulator nanowire MOSFETs

This work evaluates the operation of p-type Si
_0.7
Ge
_0.3
-on-insulator (SGOI) nanowires from room temperature down to 5.2K. Electrical characteristics are shown for long channel devices comparing narrow Ω-gate to quasi-planar MOSFETs (wide fin width). Results show oscillations in both transconductance and gate to channel capacitance curves for temperatures smaller than 50K and fin width of 20nm due to quantum confinement effects. Improvement on the effective mobility for SGOI in comparison to SOI nanowires is still observed for devices with fin width scaled down to 20nm. Similar phonon-limited mobility contribution dependence on temperature is obtained for both narrow SGOI and SOI nanowires.