Substrate Bias Effect on Dynamic Characteristics of a Monolithically Integrated GaN Half-Bridge

Abstract

his paper investigates the substrate bias effects on a monolithically integrated half-bridge fabricated using lateral GaN-on-Si technology. The dynamic characteristics, including dynamic Ron degradation and gate charge (Qg) shift, are presented for both high- and low-side GaN power devices. Compared to the grounded substrate, significant dynamic Ron degradations and decreased Qg are observed in high-side GaN power devices under negative DC substrate biases. Pulse-mode substrate biasing has also been studied with suppressed degradation by eliminating the cross-talk effect. The trade-off between dynamic Ron degradation and Qg shift has been explored under different switching frequencies for a monolithically integrated GaN half-bridge.