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Microstructure and interface control of GaN/MgAl{sub 2}O{sub 4} grown by metalorganic chemical vapor deposition: Substrate-orientation dependence

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.3606430· OSTI ID:22036662
;  [1];  [2]
  1. Advanced Electric Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)
  2. CANTech, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan)

GaN films with single-crystal and polycrystalline structure were deposited on (111) and (100) MgAl{sub 2}O{sub 4} substrates by metalorganic chemical vapor deposition using a substrate modified by chemical etching and thermal passivation. The interface structure and chemical bonding state of the GaN/MgAl{sub 2}O{sub 4} interface was investigated using angle-resolved x-ray photoelectron spectroscopy and resulting valence band spectra. Our results indicate that the Al{sub 2}O{sub 3} buffered layer induced by thermal passivation of the (111) substrate remains unchanged during GaN deposition, which is primarily responsible for the epitaxial growth of GaN on (111) MgAl{sub 2}O{sub 4} substrate. However, for the as-processed (100) substrate, interfacial reactions take place between the formed MgO-terminated surface and GaN films and GaN with a polycrystalline structure on (100) substrate forms. From the interface engineering viewpoint, the appropriate interface modification will allow control of the interface reaction to obtain high-quality GaN films for future optoelectronic devices.

OSTI ID:
22036662
Journal Information:
Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 2 Vol. 110; ISSN JAPIAU; ISSN 0021-8979
Country of Publication:
United States
Language:
English