Time evolution of off-state degradation of AlGaN/GaN high electron mobility transistors

Journal Article · Mon Jun 02 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4881637· OSTI ID:22300092

Sun, H.; Uren, M. J.

The evolution of AlGaN/GaN high electron mobility transistors under off-state stress conditions is studied by gate leakage current (I{sub g}) monitoring, electroluminescence (EL), and atomic force microscope (AFM) imaging at room temperature. It is found that the number of off-state failure sites as identified by EL increases over time during stress until it reaches a saturation value. I{sub g} increases accordingly during stress until this saturation number of failure sites is reached. AFM scanning of the device surface stripped of metal contacts and passivation reveals surface pits corresponding to the location of the EL spots. These pits have an elongated shape oriented towards the drain contact whose length is correlated with the distance to the adjacent pits and with the time since their appearance during the stress experiment. A model for the generation and evolution of the off-state stress-related failure sites is proposed consistent with the experimental results, bringing together surface migration of electrochemical species with trap-based leakage mechanisms and resulting in the formation of an exclusion zone around each failure site.

• OSTI ID: 22300092
• Journal Information: Applied Physics Letters, Vol. 104, Issue 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ATOMIC FORCE MICROSCOPY
ELECTROCHEMISTRY
ELECTROLUMINESCENCE
ELECTRON MOBILITY
GALLIUM NITRIDES
LEAKAGE CURRENT
METALS
MIGRATION
PASSIVATION
SATURATION
SPECTROSCOPY
STRESSES
SURFACES
TEMPERATURE RANGE 0273-0400 K
THERMAL DEGRADATION
TRANSISTORS
TRAPS