Monte Carlo Investigation of the High Electron Mobility Transistor

Abstract

The High Electron Mobility Transistor (HEMT) exhibits a conduction channel at the A1GaAs/GaAs interface, where the electrons are distributed in quantized subbands and constitute a quasi-two-dimensional electron gas (Q2DEG). We present, in this work, an investigation of submicron HEMT structures, based on an Ensemble Monte Carlo (EMC) model, in which the Q2DEG in the conduction channel is modeled using a two subband triangular well approximation. This simple approach allows an easy determination of the levels and of the wavefunctions in the subbands, which are necessary to evaluate the 2-D scattering rates as a function of the electron positions in the channel. This model is the development of the one presented in [1]. In particular, scattering of hot electrons, between 2-D confined states in the channel and 3-D states, has been investigated in detail, including intervalley scattering to the L-valley. In this way, the mechanisms responsible for real-space transfer of hot electrons from the conduction channel into the AlGaAs layer, as well as the confinement properties of the channel, are properly taken into account.

This work has been supported by the U.S. Army Research Office.