Polarization-Induced Versus Delta-Doped β-Ga2O3 HEMTs—A Performance Comparison

Abstract

This report presents a performance comparison between two types of β-Ga₂O₃-based high electron mobility transistors (BGO-HEMTs), where channel doping is achieved through either polarization-induced doping (PID) or delta-doped (DD) modulation doping. The study evaluates and contrasts the performance characteristics of these two types of BGO-HEMTs. Using an optical phonon model to capture enhanced electron–phonon interactions in wide bandgap semiconductors, the maximum current density is estimated in both devices. Highly polarized AlN employed as barrier layers in PID BGO-HEMTs results in significantly higher conduction band offsets, thus achieving an order of magnitude higher sheet carrier density compared to DD BGO-HEMTs. Higher 2-DEG density ensures 2.5× higher current density and one order lower on-resistance in PID over DD BGO-HEMTs. Furthermore, PID BGO-HEMTs outperform as DC switches and require 13× lower gate periphery compared to DD BGO-HEMTs for the equal power rating. In addition, AlN as a gate barrier in PID BGO-HEMTs facilitates better thermal conductivity over DD BGO-HEMTs. The achieved results show the potential of PID β-Ga₂O₃ HEMTs for emerging DC power switching and compact high-power RF electronics applications.