Hole-Induced Threshold Voltage Shift Under Reverse-Bias Stress in E-Mode GaN MIS-FET

Under reverse-bias stress (i.e., OFF-state stress with VGS <; VTH) with high drain voltage, ultraviolet (UV) illumination and larger negative gate bias are found to accelerate the positive shift in threshold voltage (VTH) of enhancement-mode GaN MIS-FETs with fully recessed gate. These results suggest a hole-induced degradation mechanism. In the absence of UV illumination, holes could be generated...