Accession Number:

ADA551863

Title:

Investigation of Gallium Nitride Transistor Reliability through Accelerated Life Testing and Modeling

Descriptive Note:

Doctoral thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT

Personal Author(s):

• Christiansen, Bradley D.

Report Date:

2011-12-01

Pagination or Media Count:

209.0

Abstract:

Gallium nitride high electron mobility transistors are attractive to the DoD for their ability to operate at high frequencies, voltages, temperatures, and power. Yet, there are concerns about the reliability of these devices. Various degradation mechanisms and their causes are proposed in the literature. A variety of reliability tests were conducted to understand these mechanisms and causes. A multi-stressor experiment revealed different failure mechanisms than are in the literature. In particular, the devices tested at high voltage in the OFF state did not degrade significantly as suggested by others reports. The validity of temperature-accelerated life testing when applied to GaN HEMT lifetime assessments is questioned. Temperature alone could not explain the differences in observed degradation. The tested devices showed excellent robustness to high forward gate stress, exhibiting only a slight change in gate diode characteristic, little decrease in maximum drain current, and a persisting breakdown voltage exceeding 200 V. The time-dependence of degradation was analyzed, and results of continuous- and pulsed-direct current stressing were compared.

Descriptors:

• *HIGH ELECTRON MOBILITY TRANSISTORS
• *LIFE TESTS
• ACCELERATED TESTING
• ARRHENIUS EQUATION
• GALLIUM NITRIDES
• RELIABILITY
• THESES

Subject Categories:

• Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE