Evaluation methodology for current collapse phenomenon of GaN HEMTs

Methods of both evaluation and analysis of current collapse (C/C) in GaN HEMTs are discussed. Recently, guidelines to the methods of evaluation of C/C in comparing device characteristics have been required as the increase in on-resistance resulting from C/C depends significantly on stress conditions and the applied method. Therefore, as a guideline, we propose the DC voltage stress and inductance load switching stress for the evaluation.

I. Introduction

By taking advantage of its low-loss high-speed switching, the GaN power device is a promising candidate for achieving high efficiency and/or downsizing of the system. This device, however, has a serious issue in that the on-resistance increases because of the current-collapse phenomenon under switching operations causing an increase in device loss and temperature [1]. As a reliability issue, the evaluation of is important.