Optimization and performance of Al_2O_3/GaN metal-oxide-semiconductor structures

摘要

We investigate electrical properties of Ni/Al_2O_3/GaN metal-oxide-semiconductor (MOS) structures having different pre-treatment of GaN surface by O_2, Ar and NH_3, combined with various temperature of annealing. MOS and reference Ni/GaN Schottky contact are characterized using current-voltage and capacitance-voltage methods. MOS structures compared with the Schottky contact ones show leakage current reduction for all types of processing, from 3 to 5 orders of magnitude in reverse direct. We observed substantial influence of the pre-treatment on electrical parameters of MOS structures.