Numerical analysis of the Impact of Gate Geometry variations on the Reliability of AlGaN/GaN HEMT

Converse piezoelectric strain leads to degradations such as structural deformation, creation of traps, etc. in AlGaN/GaN high electron mobility transistors (HEMTs). In this paper, an approach to reduce the converse piezoelectric strain in the AlGaN barrier layer is presented by adopting a filleted gate (FG) geometry HEMT. It is observed that in FG HEMT, the peak vertical electric field, and vertical converse piezoelectric strain reduces by almost 25%, while electron temperature reduces by 20% in comparison to the traditionally used rectangular gate HEMT. It is also observed that the reduction in peak vertical electric field, and peak vertical converse piezoelectric strain is more than staircase gate geometry device. Thus, the proposed FG HEMT is expected to be a potential candidate which can tackle converse piezoelectric strain induced damages in AlGaN/GaN HEMT devices.