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Traps and defects in pre‐ and post‐ stressed AlGaN–GaN high electron mobility transistors
Author(s) -
Sin Yongkun,
Foran Brendan,
Joh Jungwoo,
del Alamo Jesus A.
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201001079
Subject(s) - materials science , optoelectronics , transistor , deep level transient spectroscopy , metalorganic vapour phase epitaxy , enhanced data rates for gsm evolution , high electron mobility transistor , degradation (telecommunications) , stress (linguistics) , nanotechnology , layer (electronics) , electronic engineering , electrical engineering , silicon , epitaxy , telecommunications , linguistics , philosophy , voltage , engineering , computer science
We used deep level transient spectroscopy (DLTS) and HR‐TEM techniques to study traps and defects in pre‐ and post‐stressed AlGaN/GaN high electron mobility transistors (HEMTs) grown by MOCVD on semi‐insulating SiC substrates. DLTS identified two dominant traps with activation energies of 0.5 and 0.7 eV in both pre‐ and post‐stressed GaN HEMTs. Electrical stress resulted in a significant increase in the density of 0.5 eV traps. This is attributed to point defects (most likely N antisites) in the AlGaN barrier and clearly suggests that these traps play a critical role in degradation of the devices. Cross‐sectional TEM confirmed physical damage on the edge of the gate that was likely due to the inverse piezoelectric effect.