X‐ray absorption spectroscopic study on Ti/n‐GaN

Abstract

Formation of low resistance and thermally stable ohmic contacts to GaN is of considerable importance for device applications. Several metallization schemes for ohmic contacts to n‐GaN with low contact resistance have been proposed and investigated by different techniques. We investigate 500 Å Ti/n‐GaN contacts of as‐deposited and rapid furnace annealed at 900 °C for 30 s, using X‐ray diffraction pattern, I–V measurements, and X‐ray absorption near edge spectra at Ti K‐ and L3,2‐edges and elucidate the mechanism responsible for the high ohmic behaviour. These measurements indicate the formation of an interfacial TixN layer and intermetallic alloys of Ti and Ga at the Ti/n‐GaN interface upon high temperature annealing. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)