Reliability of GaN HEMTs: Current degradation in GaN/AlGaN/AlN/GaN HEMT

Electrical reliability of the AlGaN/GaN material system in both the on and off state regimes is a fundamental problem to be solved before the widespread use of this technology. The two major reliability concerns in this technology is electric field induced strain degradation also known as electromechanical coupling and current collapse mechanism. In the present work, an electro thermal particle based device simulator has been developed to address these two issues. It consists of a Monte Carlo-Poisson solver that is self-consistently coupled with a thermal solver for both the acoustic and the optical phonon baths. This simulator has been used to understand the physics behind these mechanisms that lead to reliability concerns.