Investigation of indium tin oxide/zinc oxide multilayer ohmic contacts to <i>n</i>-type GaN isotype conjunction

Abstract

The ohmic performance of the ITO/ZnO multilayer deposited on n-type GaN layer was investigated. The best thermal annealing condition achieved for ohmic contact was 5 min at 500 °C, in hydrogen ambient. The measured specific contact resistance was 3×10−4 Ω cm2. Ohmic formation mechanisms would be attributed to the ITO/n-ZnO/n-GaN isotype conjunction and the reduction conduction band offset due to the quantum confinement effects in the thin ZnO layer.