Investigation on mechanisms of current saturation in gateless AlGaN/GaN heterostructure device

Abstract

The current saturation in a gateless AlGaN/GaN heterostructure device is investigated in this letter. Analysis of the micro-Raman spectroscopy results indicated that the self-heating effect could be eliminated by the 10 μs pulse measurement. Based on the proposed multi-probe gateless AlGaN/GaN heterostructure device, the uniform channel depletion is experimentally verified even in the case of current saturation. The pre-stress measurement and transient current measurement results suggest that the surface traps with an extracted surface trap energy level of 0.13 eV are uniformly charged along the channel. Furthermore, a forward electron injection explanation is proposed and confirmed by TCAD simulation.