Brittle-ductile relaxation kinetics of strained AlGaN/GaN heterostructures

Journal Article · Mon Mar 20 04:00:00 EST 2000 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.126087· OSTI ID:20215689

Hearne, S J ^[1]; Han, J ^[1]; Lee, S R ^[1]; Floro, J A ^[1]; Follstaedt, D M ^[1]; Chason, E ^[2]; Tsong, I S. T. ^[3]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
2. Department of Material Science, Brown University, Providence, Rhode Island 02912 (United States)
3. Department of Physics and Astronomy, Arizona State University, Tempe, Arizona 85287-1504 (United States)

We have directly measured the stress evolution during metal-organic chemical vapor deposition of AlGaN/GaN heterostructures on sapphire. In situ stress measurements were correlated with ex situ microstructural analysis to determine directly a critical thickness for cracking and the subsequent relaxation kinetics of tensile-strained Al{sub x}Ga{sub 1-x}N grown on GaN. Cracks appear to initiate the formation of misfit dislocations at the AlGaN/GaN interface, which account for the majority of the strain relaxation. (c) 2000 American Institute of Physics.

• OSTI ID: 20215689
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 12 Vol. 76; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
BRITTLE-DUCTILE TRANSITIONS
CHEMICAL VAPOR DEPOSITION
CRACKS
DISLOCATIONS
EXPERIMENTAL DATA
GALLIUM NITRIDES
HETEROJUNCTIONS
STRAINS