Local structures of free-standing Al{sub x}Ga{sub 1-x}N thin films studied by extended x-ray absorption fine structure

Journal Article · Mon Dec 27 04:00:00 EST 1999 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.125548· OSTI ID:20217757

Yu, Kin Man ^[1]; Shan, W ^[1]; Glover, C J ^[2]; Ridgway, M C ^[2]; Wong, William S ^[3]; Yang, W ^[4]

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1. Center for Advanced Materials, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2. Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra, (Australia)
3. Department of Materials Science and Mineral Engineering, University of California, Berkeley, California 94720 (United States)
4. Honeywell Technology Center, Plymouth, Minnesota 55420 (United States)

Local structural information for the first two atomic shells surrounding Ga atoms in free standing Al{sub x}Ga{sub 1-x}N alloy films has been obtained by extended x-ray absorption fine structure spectroscopy. For an AlN mole fraction ranging from 0 to 0.6, we found that the first shell Ga-N bond length had only a weak composition dependence, roughly one quarter of that predicted by Vegard's Law. In the second shell, the Ga-Ga bond length was significantly longer than that of Ga-Al ({delta}{approx}0.04-0.065 Aa). A bond-type specific composition dependence was observed for the second shell cation-cation distances. While the composition dependence of the Ga-Ga bond length is {approx}70% of that predicted by Vegard's Law, the Ga-Al bond length was essentially composition independent. These results suggested that local strain in Al{sub x}Ga{sub 1-x}N was also accommodated by lattice distortion in the Al cation sublattice. (c) 1999 American Institute of Physics.

• OSTI ID: 20217757
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 26 Vol. 75; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
ALUMINIUM NITRIDES
BOND LENGTHS
CHEMICAL COMPOSITION
EXPERIMENTAL DATA
FINE STRUCTURE
GALLIUM NITRIDES
LATTICE PARAMETERS
STRUCTURAL CHEMICAL ANALYSIS
THIN FILMS
X-RAY SPECTROSCOPY