Search

In this article, the impacts of the off-state gate bias (VGS,OFF) on dynamic on-resistance (RON) are systematically investigated in commercial Schottky-type p-GaN Gate high-electron-mobility transistors. Double-pulse tester and pulsed I–V system are adopted to evaluate the dynamic RON with various off-state gate and drain bias (VDS,OFF) under hard- and soft-switching conditions. More negative VGS,OFF can aggravate the dynamic RON degradation under both soft- and hard-switching, especially when switching with a high VDS,OFF. The impacts of VGS,OFF on switching transients and off-state stress are investigated separately to reveal the underlying mechanisms, which are found to be associated with the generation and movements of holes. The off-state gate bias of the voltage-driving scheme needs to be carefully considered according to the identified mechanisms in terms of dynamic on-resistance degradation. [ABSTRACT FROM AUTHOR]

In this paper, systematic characterization and the corresponding suppression strategies of dynamic OFF-state leakage current (${I}_{ \mathrm{\scriptscriptstyle OFF}}$) in Schottky-type p-GaN gate high-electron-mobility transistors (HEMTs) are presented based on fast pulsed ${I}$ – ${V}$ measurement and consecutive switching measurement. It is found that the high ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ under dynamic pulse mode without hole injection is a result of the reduced voltage blocking capabilities (both lateral and vertical) with weaker trapping effect in the buffer, and the dynamic ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ induced by ON-state hole injection is caused by further increased lateral conductivity through the buffer from source to drain. The corresponding behaviors under continuous waveforms with different switching conditions are analyzed to identify effective approaches for the suppression of dynamic ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ in practical switching operations. A higher temperature is shown to be beneficial to the reduction of the dynamic ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ induced by ON-state hole injection. To completely eliminate the dynamic ${I}_{ \mathrm{\scriptscriptstyle OFF}}$ caused by ON-state hole injection and minimize the OFF-state power consumption in practical power switching applications, a sufficiently large negative OFF-state gate bias (e.g., ${V}_{\text {GS}, \mathrm{\scriptscriptstyle OFF}}\le -{3}$ V) is recommended in the gate driver turn-off voltage design for the Schottky-type p-GaN gate HEMTs. [ABSTRACT FROM AUTHOR]