Ge-SixGe1-x core-shell nanowire tunneling field-effect transistors

We report the fabrication and experimental investigation of Ge-Si
_x
Ge
_1-x
core-shell nanowire (NW) tunneling field effect transistors (TFETs). Low energy ion implantation was used to highly dope the NW TFET source (S) and drain (D). The NW TFETs show ON-state currents of up to I
_ON
~ 5 μA/μm, and the ambipolar behavior is suppressed by achieving asymmetric doping concentrations at S/D. Furthermore, the NW TFET subthreshold slope (SS) shows little temperature dependence down to 77K, consistent with band-to-band tunneling (BTBT) being the dominant carrier injection mechanism.