Potential and electric field analysis of field plated AlGaN/GaN HEMT for high voltage applications using 2-D analytical approach

Abstract

A physics-based 2-D analytical model is developed for field plated AlGaN/GaN high electron mobility transistor (HEMT) and the effect of field plate on potential and electric field is analyzed. The complete generalized theory developed includes the dependence of electric field and electric potential distribution on (i) different dielectric materials and (ii) dielectric thickness below the field plate. An extensive study of the effect of various non-field plate parameters such as doping concentration in the AlGaN layer, drain source voltage, and gate source voltage has also been carried out. It is observed that with the introduction of field plate, primary peak of electric field gets reduced and redistribution of electric field occurs in a better way with the introduction of much smaller secondary electric field peak. This leads to improved breakdown voltage thus making the device suitable for high voltage applications. The analytical results are also compared with the simulated results extracted with ATLAS 2D device simulation. The good agreement validates the analytical approach.