Trench edge termination in a GaN-based power device

Abstract

The comfort of the modern society is somehow relied on production of high voltage and high frequency devices. Being mature in performance, wide bandgap semiconductors have replaced silicon-based devices. However, wide bandgap semiconductor devices are plagued with their premature breakdown, which owes to edge effects. Present work demonstrates breakdown voltage enhancement in GaN based Schottky diode using trench edge termination technique. Al 2 O 3 was filled in the trench of the structure. The atlas module of the Silvaco TCAD software has been used to replicate the device structure. Numerous models for ionization, recombination, impact ionization and mobility have been used. The breakdown voltage of the device is estimated to be 350 V due to the increase in the electric field at the edges. Using trench termination, the edge electric field crowding has been found spreading away from the edges of the device and in the Al 2 O 3 layer. As a consequence, the trench edge terminated device has a reverse breakdown voltage increased to 1800 V.