On impact ionization and avalanche in gallium nitride

Dong Ji,Srabanti Chowdhury

doi:10.1063/5.0031504

Abstract

This paper is dedicated to discussing the physics and applications of avalanche on III-Nitrides, primarily using Gallium Nitride as the example. Understanding the breakdown phenomenon in wide bandgap materials is of great interest to the device and circuit community as it directly impacts design and applications with these emerging semiconductors. In this paper, first, we go over the various approaches that have been reported on estimating the impact ionization coefficients in GaN, then discuss about the estimation of the critical electric field for punch-through and non-punch-through designs, and, finally, go over two avalanche-based devices that we have recently demonstrated.

Highlights

This paper is dedicated to discussing the physics and applications of avalanche on III-Nitrides, primarily using Gallium Nitride as the example
First, we go over the various approaches that have been reported on estimating the impact ionization coefficients in GaN, discuss about the estimation of the critical electric field for punch-through and non-punch-through designs, and, go over two avalanche-based devices that we have recently demonstrated
Based on the impact ionization coefficients from Ref. 9, one can calculate the breakdown electric field by solving the impact ionization integration equations in p–n junctions where the upper limit of the integral is set by the distance that the carriers can travel generating electron–hole pairs (EHPs) through multiplication,[16]

Summary

Introduction

First, we go over the various approaches that have been reported on estimating the impact ionization coefficients in GaN, discuss about the estimation of the critical electric field for punch-through and non-punch-through designs, and, go over two avalanche-based devices that we have recently demonstrated. Devices that are limited by avalanche (such as power diodes and transistors) or dependent on avalanche [such as Avalanche Photo Diodes (APDs) and impact ionization avalanche transit time (IMPATT) diodes] have completely different electric field profiles.

Results

Conclusion