Diffusion Effect between Schottky Metals and AlGaN/GaN Heterostructure during High Temperature Annealing Process

Abstract

AbstractWe have investigated the change of the Schottky contact surface and the interface between Schottky metals and AlGaN/GaN heterostructure after the annealing process for 35 min at 300 °C. The secondary ion mass spectroscopy (SIMS) and the scanning electron microscopy (SEM) show that the Schottky metals and AlGaN/GaN heterostructure interacted actively during the annealing process. The atoms in Schottky contact and AlGaN/GaN heterostructure diffused interactively and the surface roughness of Schottky contact was increased. After the annealing process for fabricated AlGaN/GaN High-Electron-Mobility Transistor (HEMT), the threshold voltage was shifted by +0.2 V and the leakage current was decreased by 40 %.