Effect of Ozone Cleaning and Annealing on Ti∕Al∕Pt∕Au Ohmic Contacts on GaN Nanowires

Abstract

We report studies on the effect of UV∕ozone cleaning on n-type GaN nanowires prior to ohmic contact deposition and the effect of annealing temperature on the total resistance of the contacted nanowires. The UV∕ozone cleaning for periods of reduced surface carbon and oxygen contamination, as determined by Auger electron spectroscopy measurements and led to a specific contact resistivity of after annealing in the range . After subtraction of this contact resistivity from the total resistance of the nanowires, it was found that the ozone treatment reduced the apparent resistivity from . These results show the importance of surface cleaning in extracting the transport properties of GaN nanowires.