Characterization of Ni/i-AlGaN/GaN Schottky Samples Fabricated after H_3PO_4-Etching

摘要

Electrical properties of bare i-AlGaN/GaN and Ni/i-AlGaN/GaN Schottky samples with various thickness of the AlGaN layer, prepared by wet-etching in a hot-H_3PO_4 solution, were systematically investigated by Hall effect, I-V and C-V measurements. For the bare samples, the thinner the AlGaN layer, the lower 2DEG density according to the theoretical curve with a constant surface barrier height. For Schottky samples, both forward and reverse currents increase with decreasing the AlGaN layer, and the behavior can be explained by combined leakage currents due to leaky patches and simple tunneling through the barrier. OV measurements supported fairly uniform etching of the AlGaN layer except crystal defects.