Determination of the Gate Breakdown Mechanisms in p-GaN Gate HEMTs by Multiple-gate-sweep Measurements

TL;DR

This paper introduces a novel multiple-gate-sweep measurement technique to identify and analyze different gate breakdown mechanisms in p-GaN gate HEMTs, providing new insights into device failure modes.

Contribution

The study presents the first identification of three distinct breakdown mechanisms in p-GaN gate HEMTs using a novel measurement method, validated by SEM and temperature analysis.

Findings

Three breakdown mechanisms identified: metal/p-GaN junction, p-GaN/AlGaN/GaN junction, passivation-related.

The method effectively distinguishes different breakdown modes in the same device.

Temperature dependence of each breakdown mechanism was characterized.

Abstract

In this work, we studied the gate breakdown mechanisms of p-GaN gate AlGaN/GaN HEMTs by a novel multiple-gate-sweep-based method. For the first time, three different breakdown mechanisms were observed and identified separately in the same devices: the metal/p-GaN junction breakdown, the p-GaN/AlGaN/GaN junction breakdown, and the passivation related breakdown. This method is an effective method to determine the breakdown mechanisms. The different BD mechanisms were further confirmed by scanning electron microscopy (SEM). Finally, the temperature dependences of the three BD mechanisms were measured and compared. This analysis method was also employed in the devices with a different passivation material and showed its applicability.