An analytical model for current-voltage characteristics of quantum-well heterojunction field-effect transistors

Abstract

An analytical model has been developed for Insulated-Gate Inverted-Structure High Electron Mobility Transistors (I 2-HEMTs) and Double Heterojunction High Electron Mobility Transistors (DH-HEMTs). In this model, the quasi-triangular potential well approximation is used to calculate the top-heterojunction Fermi potential as a function of the 2DEG concentration inside the quantum-well. A closed-form charge control formula has been derived. The 2DEG concentration vs gate voltage obtained from this model is found to agree with the self-consistent numerical model. Based on this charge-control model, the current-voltage relationships for I 2-HEMTs and DH-HEMTs are obtained. In these relationships, the buffer 2DEG channel conduction beneath the quantum well and cross linking current inside the quantum well are considered. This model is compared with the experimental results and found to be fairly accurate.