A Top-Gate Gan Nanowire Metal-Semiconductor Field Effect Transistor With Improved Channel Electrostatic Control

A uniformly n-type doped GaN: Si nanowire (NW), with a diameter of d = 90 nm and a length of 1.2 mu m, is processed into a metal-semiconductor field effect transistor (MESFET) with a semicylindrical top Ti/Au Schottky gate. The FET is in a normally-ON mode, with the threshold at -0.7V and transconductance of gm similar to 2 mu S (the transconductance normalized with NW diameter g(m)/d> 22 mS/mm). It enters the saturation mode at V-DS similar to 4.5 V, with the maximum measured drain current IDS = 5.0 mu A and the current density exceeding J(DS)> 78 kA/cm(2). (C) 2016 AIP Publishing LLC.