Analysis of Improved 2D Electron Gas Mobility in InAlN/AlN/InGaN High‐Electron‐Mobility Transistors with GaN Interlayer

Abstract

Herein, the physical mechanism of the GaN interlayer for improving 2D electron gas (2DEG) mobility in the InGaN channel using an intersub‐band scattering model is systematically elucidated. The model takes into account various scattering mechanisms between the first four sub‐bands, in which the wavefunction of each sub‐band is obtained by self‐consistently solving 1D Schrödinger−Poisson equations. The total 2DEG mobility is obtained by averaging the sub‐band mobility by the percentage of electrons in the different sub‐bands. The effect of introducing different thicknesses of the GaN interlayer on the mobility limited by various scattering mechanisms is discussed in detail, especially polar optical phonon scattering and alloy disorder scattering. The calculated results are well supported by the reported experimental data, validating the correctness of the model.