High-Performance AlGaN Double Channel HEMTs with Improved Drain Current Density and High Breakdown Voltage

Yachao Zhang,Yue Hao,Lin Du,Yao Li,Yifan Li,Jincheng Zhang,Zhizhe Wang,Jia Wang,Yiming Shen,Shengrui Xu

doi:10.1186/s11671-020-03345-6

Abstract

In this work, AlGaN double channel heterostructure is proposed and grown by metal organic chemical vapor deposition (MOCVD), and high-performance AlGaN double channel high electron mobility transistors (HEMTs) are fabricated and investigated. The implementation of double channel feature effectively improves the transport properties of AlGaN channel heterostructures. On one hand, the total two dimensional electron gas (2DEG) density is promoted due to the double potential wells along the vertical direction and the enhanced carrier confinement. On the other hand, the average 2DEG density in each channel is reduced, and the mobility is elevated resulted from the suppression of carrier-carrier scattering effect. As a result, the maximum drain current density (Imax) of AlGaN double channel HEMTs reaches 473 mA/mm with gate voltage of 0 V. Moreover, the superior breakdown performance of the AlGaN double channel HEMTs is also demonstrated. These results not only show the great application potential of AlGaN double channel HEMTs in microwave power electronics but also develop a new thinking for the studies of group III nitride-based electronic devices.

Highlights

Group III nitride-based high electron mobility transistors (HEMTs) have been identified as the most promising candidate for next-generation microwave power electronics owing to their fast-switching speed and lowswitching loss [1–5]
Zhang et al fabricated the AlGaN channel HEMTs with a novel ohmic/Schottky-hybrid drain contact, and a record high breakdown voltage of more than 2200 V was obtained for the AlGaN channel HEMTs [11]
Xiao et al proposed the AlGaN channel heterostructures with high Two dimensional electron gas (2DEG) mobility of 807 cm2/V·s, and the records of maximum drain current and Ion/Ioff ratio were reported for the fabricated AlGaN channel HEMTs [14]

Summary

Introduction

Group III nitride-based high electron mobility transistors (HEMTs) have been identified as the most promising candidate for next-generation microwave power electronics owing to their fast-switching speed and lowswitching loss [1–5]. In view of the larger bandgap and superior thermal stability of AlGaN over GaN, AlGaN channel devices have been proposed as promising candidate to further. Afterwards, Nanjo et al further promoted the breakdown voltage of the Al0.40Ga0.60N/Al0.15Ga0.85N HEMTs to 1700 V [8]. Zhang et al fabricated the AlGaN channel HEMTs with a novel ohmic/Schottky-hybrid drain contact, and a record high breakdown voltage of more than 2200 V was obtained for the AlGaN channel HEMTs [11]. Xiao et al proposed the AlGaN channel heterostructures with high 2DEG mobility of 807 cm2/V·s, and the records of maximum drain current and Ion/Ioff ratio were reported for the fabricated AlGaN channel HEMTs [14]. Whereafter, Xiao et al proposed the normally off HEMTs with

Methods

Results

Conclusion