A surface-potential based compact model for GaN HEMTs incorporating polarization charges

Abstract

This paper introduce a method for incorporating polarization sheet charges into compact modeling in transistors. The Poisson equation is solved directly with a Dirac-delta function sheet charge at the heterojunction to obtain an analytical equation for the surface potential. This surface potential is then used to calculate the HEMT characteristics. Thus, the results of this work for the first time make an explicit connection between the material properties of the HEMT heterostructure with a surface potential based compact model through the polarization sheet charge. Furthermore, the authors have extended the intrinsic model by including field-dependent mobility and velocity saturation. The developed model should prove helpful in designing of devices and circuits.