Non-recessed-gate quasi-E-mode double heterojunction AlGaN/GaN high electron mobility transistor with high breakdown voltage

Abstract

A non-recessed-gate quasi-E-mode double heterojunction AlGaN/GaN high electron mobility transistor (quasi-E-DHEMT) with a thin barrier, high breakdown voltage and good performance of drain induced barrier lowering (DIBL) was presented. Due to the metal organic chemical vapor deposition (MOCVD) grown 9-nm undoped AlGaN barrier, the effect that the gate metal depleted the two-dimensiomal electron gas (2DEG) was greatly impressed. Therefore, the density of carriers in the channel was nearly zero. Hence, the threshold voltage was above 0 V. Quasi-E-DHEMT with 4.1-μm source-to-drain distance, 2.6-μm gate-to-drain distance, and 0.5-μm gate length showed a drain current of 260 mA/mm. The threshold voltage of this device was 0.165 V when the drain voltage was 10 V and the DIBL was 5.26 mV/V. The quasi-E-DHEMT drain leakage current at a drain voltage of 146 V and a gate voltage of −6 V was below 1 mA/mm. This indicated that the hard breakdown voltage was more than 146 V.