The formation and characterization of electrical contacts (Schottky and Ohmic) on gallium nitride nanowires

Abstract

We report on the fabrication and characterization of Ti/Au Ohmic contacts to unintentionally doped gallium nitride (n-GaN) nanowires. The specific contact resistance and resistivity were determined to be similar to 1.1 x 10(-5) +/- 5 x 10(-6) Omega cm(2) and similar to 6.9 x 10(-3) +/- 3 x 10(-4) Omega cm, respectively, with a diameter of similar to 140 nm using a transmission line model (TLM). We also present the electrical characterizations of metal/GaN nano-Schottky diodes with four Schottky metals (Al, Ti, Cr and Au) on unintentionally doped GaN nanowires using current-voltage (I-V) characteristics at room temperature. We observed the abnormal electrical characteristics of GaN nano-Schottky diodes for each Schottky metal.