A Modified Boost Converter Topology for Dynamic Characterization of Hot Carrier and Trap Generation in GaN HEMTs

TL;DR

This paper presents a modified boost converter circuit to accelerate and analyze failure mechanisms in GaN HEMTs, enabling better reliability modeling and lifetime prediction for high-power devices.

Contribution

It introduces a novel circuit-based method for rapid reliability testing of GaN HEMTs, specifically targeting hot carrier and trap generation mechanisms.

Findings

Logarithmic increase in $R_{DS(on)}$ over time matches the MTOL model.

Stress tests at higher voltages validated $ abla ext{LO}$ energy against theoretical data.

Method enables accelerated reliability assessment with minimal input requirements.

Abstract

Modern microelectronic systems require long term operational stability, necessitating precise reliability models to predict device lifecycles and identify governing failure mechanisms. This is particularly critical for high power GaN High-Electron-Mobility Transistors (HEMTs), where reliability research has historically trailed behind low power digital counterparts. This study introduces a novel application of a modified boost converter circuit designed to investigate GaN failure mechanisms, specifically targeting the determination of reliability factors for the MTOL model. By utilizing a high duty cycle, the circuit stresses the device at maximum rated voltages and currents with minimal input requirements, accelerating hot carrier and trap generation without immediate detrimental failure. Experimental validation was conducted using an EPC 2038 GaN transistor under a constant drain current of 400 mA and a duty cycle of 0.7. The results confirmed that the increase in Drain-Source on-resistance ($R_{DS(on)}$) follows a logarithmic trend over time, consistent with the EPC Phase 12 reliability model. While initial tests at 40V did not successfully validate the longitudinal optical phonon scattering energy ($\hbar\omega_{LO}$), but were reasonably acceptable, subsequent stress tests at 70V and 100V yielded $\hbar\omega_{LO}$ values that were successfully validated against existing theoretical and experimental data. This methodology provides a robust framework for predicting performance and lifetime across varying operational parameters in modern power electronics.