Numerical optimization of In-mole fractions and layer thicknesses in Al_xGa_(1-x)N/AlN/GaN high electron mobility transistors with InGaN back barriers

摘要

The effects of the In-mole fraction (x) of an In_xGa _(1-x)N back barrier layer and the thicknesses of different layers in pseudomorphic Al_yGa_(1-y)N/AlN/GaN/In_xGa _(1-x)N/GaN heterostructures on band structures and carrier densities were investigated with the help of one-dimensional self-consistent solutions of non-linear SchrdingerPoisson equations. Strain relaxation limits were also calculated for the investigated Al_yGa_(1-y)N barrier layer and In_xGa_(1-x)N 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.