Orientational Dependence in Device Performances of InAs and Si Nanowire MOSFETs Under Ballistic Transport

We evaluate drive currents and consumption powers of InAs and Si nanowire metal-oxide-semiconductor field-effect transistors (MOSFETs) with various crystal orientations, by using a ballistic MOSFET model coupled with tight-binding band structure calculation. We demonstrate that performance dependence on the wire orientation is not significant in InAs NWFETs compared to Si NWFETs, due to an isotropic nature of the Gamma valley, and furthermore, a lower power switching is expected in InAs NWFETs even if the gate oxide thickness reduces down to a quantum capacitance limit. The present results suggest that InAs NWFETs have the advantage over the Si counterpart in terms of lower power operation and flexibility in layout design of integrated circuits.