Reverse blocking p-GaN gate AlGaN/GaN HEMTs with hybrid p-GaN ohmic drain

Abstract

A normally-off reverse blocking high electron mobility transistor (HEMT) with p-GaN gate and hybrid p-GaN ohmic drain (p-GaN RB-HEMT) has been fabricated and investigated to achieve reverse blocking capability. Compared with conventional p-GaN gate HEMT with ohmic drain (p-GaN HEMT), the proposed device features that a p-GaN layer is embedded into the ohmic drain. This could realize not only the reverse blocking capability, but also the effective suppression of reverse leakage current based on the formed pn junction drain, and an ultralow reverse leakage current of <1 nA/mm at −100 V and a reverse breakdown voltage of −688 V at 1 μA/mm have been achieved in the fabricated p-GaN RB-HEMT. In addition, the device shows a positive threshold voltage of 1.6 V and a forward breakdown voltage of 666 V. Meanwhile, the Von and Ron have a linear relationship with the increase in p-GaN drain dimension.