Evaluation and Establishment of an Empirical Model for the Dynamic Ron Effect of GaN Power Device in Hard Switching Mode

In recent years, the rapid popularization of GaN HEMT devices in power applications has made the traditional GaN static SPICE model unable to meet the requirements of high-voltage and high-frequency circuit design, due to the dynamic on-resistance ( ${R} _{\text {on}}$ ) effect. In this article, we evaluate the dynamic ${R} _{\text {on}}$ effect of a commercial 100-V Schottky-type p-GaN HEMT in the hard switching mode and propose an empirical dynamic model. The pulse test results show that the gate-to-drain voltage stress is the main cause of the dynamic ${R} _{\text {on}}$ effect. The peak electric field located at the AlGaN barrier layer and channel of the device will cause threshold voltage positive shift and hot electron effect. These two physical mechanisms that cause the dynamic ${R} _{\text {on}}$ effect are verified by the TCAD simulation. Meanwhile, we calculated the contribution of the two physical mechanisms to the dynamic ${R} _{\text {on}}$ under different operation conditions. Based on the test and analysis results, the equivalent circuit is added to the static SPICE model of the device. The proposed empirical model could well simulate the dynamic ${R} _{\text {on}}$ characteristic and switching behavior of the device in hard switching mode.