COMPARATIVE STUDY OF InAlN AND InGaN SUPER BACK BARRIER LAYER ON P-GATE/AlGaN/GaN HEMT

Abstract

Attractive properties of GaN allows it to be used in power electronic devices in various space and defence applications like satellites and radars. GaN has wide band gap of 3.4eV and can operate at high temperature (>300 0C) as compare to silicon, which is being used in conventional devices. The common AlGaN/GaN HEMTS are normally-on due to natural induction of high density Electron gas (2DEG) in the channel. As compare to these devices normally-off devices have advantages of positive and stable threshold voltage, high breakdown field and low on-resistance. In this report, we have done comparative study of InAlN and InGaN back barrier with conventional GaN buffer in p-GaN/AlGaN/GaN HEMT using Silvaco TCAD software. Carrier spilling in the channel is reduced which resulted in better 2DEG confinement in the channel. Maximum electric field in the channel is 1.17 MV/cm that is one order higher than conventional GaN Buffer. Transfer characteristics and ION/IOFF ratio are improved with back barrier. Higher ION/IOFF ratio in InAlN back barrier makes it to be more power efficient and reliable p-GaN/AlGaN/GaN device than InGaN back barrier.