Study of two-dimensional electron gases wave function in double-heterojunction transistors

Abstract

To study the electron transport properties in high electron mobility transistors (HEMTs), it is essential to have a correct estimation for electron density distribution. The introduction of back barriers in GaN-based HEMTs leads to a modified profile of a two-dimensional (2D) electron wave function, which can no longer be described by the standard Fang-Howard model. To address this change, a numerical model is developed for the wave function calculation based on the variational Hartree method. An electron density profile in the GaN channel with AlGaN top and back barriers has been simulated. The results are in good agreement with those obtained from self-consistent Poisson-Schrödinger simulation. The centroid of the 2D electron gas is also calculated as a function of the Al composition in the AlGaN back barrier.