Self-Heating effect Simulation of GaN HFET Devices – 4H-SiC and Sapphire Substrate Comparison

I. Introduction

GaN-based Hetero-Field Effect Transistors have been investigated in high power and high frequency electronics devices. However, such improved performance is still subject to influence of surface and buffer traps. The role and dynamics of traps and their effect on the GaN HFET have already been investigated [1]. In addition to the formation of the 2DEG, an adequate numerical model of device charge control implies proper modulation of the 2DEG in ATLAS [2].

In this paper, in order to understand and control the self-heating effect, the device was simulated including this effect on a 4H-SiC and a Sapphire substrate, and Id-Vd characteristics were compared using the ATLAS 2D device simulator.