Numerical optimization of In-mole fractions and layer thicknesses in AlxGa1 xN/AlN/GaN high electron mobility transistors with InGaN back barriers

Abstract

The effects of the In-mole fraction (x) of an InxGa1 xN back barrier layer and the thicknesses of different layers in pseudomorphic AlyGa1 yN/AlN/GaN/InxGa1 xN/GaN heterostructures on band structures and carrier densities were investigated with the help of one-dimensional self-consistent solutions of non linear Schrodinger–Poisson equations. Strain relaxation limits were also calculated for the investigated ¨ AlyGa1 yN barrier layer and InxGa1 xN back barriers. From an experimental point of view, two different optimized structures are suggested, and the possible effects on carrier density and mobility are discussed.