Modeling of High Composition AlGaN Channel HEMTs with Large Threshold Voltage

TL;DR

This paper uses 2D simulations to explore high composition AlGaN channel HEMTs, demonstrating their potential for high threshold voltages and power applications with comparable on-resistance to GaN devices.

Contribution

It introduces detailed modeling of high composition AlGaN channels in HEMTs, highlighting their ability to achieve high threshold voltages suitable for power switching.

Findings

Threshold voltages over 3 V achievable with AlGaN channels

AlGaN HEMTs have comparable on-resistance to GaN devices

Power figures of merit are favorable across temperature ranges

Abstract

We report on the potential of high electron mobility transistors (HEMTs) consisting of high composition AlGaN channel and barrier layers for power switching applications. Detailed 2D simulations show that threshold voltages in excess of 3 V can be achieved through the use of AlGaN channel layers. We also calculate the two-dimensional electron gas (2DEG) mobility in AlGaN channel HEMTs and evaluate their power figures of merit as a function of device operating temperature and Al mole fraction in the channel. Our models show that power switching transistors with AlGaN channels would have comparable on-resistance to GaN-channel based transistors for the same operation voltage. The modeling in this paper shows the potential of high composition AlGaN as a channel material for future high threshold enhancement mode transistors.