15 nm diameter InAs nanowire MOSFETs

InAs is an attractive channel material for III-V nanowire MOSFETs and early prototype high performance nanowire transistors have been demonstrated
¹
. As the gate length is reduced, the nanowire diameter must be scaled quite aggressively in order to suppress short-channel effects
²
. However, a reduction in transconductance (g
_m
) and drive current (I
_ON
) could be expected due to increased surface scattering for thin wires. We present data for the device properties of thin InAs nanowires, with diameters in the 15 nm range, and investigate possible improvements of the performance focusing on transistor applications. In order to boost I
_ON
, the source and drain resistance need to be reduced. Several doping sources were therefore evaluated in the study, among them selenium (Se), tin (Sn) and sulphur (S) to form n-i-n structures. We report very high current densities, up to 33 MA/cm
²
, comparable to modern HEMTs
³
, and a normalized transconductance of 1.8 S/mm for a nanowire with an intrinsic segment of nominally 150 nm and a diameter of 15 nm.