Investigation of p-GaN tri-Gate normally-Off GaN Power MOSHEMTs

Abstract

In this work, we present the investigation of the combination of p-GaN gate and tri-gate structures to achieve normally-off operation on GaN-on-Si MOSFETs. We have developed and optimized a selective and low-damage p-GaN etching recipe to stop at the AlGaN barrier and minimize the degradation in on-resistance (RON). The p-GaN length and tri-gate filling factor (FF) were optimized to achieve a good trade-off between high threshold voltage (VTH) and low RON. The excellent channel control capability offered by tri-gate structure led to a reduced OFF-state leakage current (IOFF), higher ON/OFF ratio, smaller sub-threshold slope (SS) compared to similar planar p-GaN devices. These results unveil the excellent prospects of p-GaN tri-gate technology for future power electronics applications.

Novel GaN-based double-channel p-heterostructure field-effect transistors with a p-GaN insertion layer

“…GaN-based high electron mobility transistors (HEMTs) on Si substrates have been widely explored in research, and fabricated as power switches with a high breakdown voltage for commercial usage. [1,2] The application of discrete GaN-based power switches requires the collaboration of Si-based peripheral circuit structures such as gate driver, controller and protection modules. However, the differences between the two materials and the interconnections between devices can introduce extra parasitic effects to the power conversion circuit, which induce instability of GaN power switches and circuits.…”