Complex and incommensurate ordering in Al{sub 0.72}Ga{sub 0.28}N thin films grown by plasma-assisted molecular beam epitaxy

Journal Article · Mon May 01 00:00:00 EDT 2006 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2201898· OSTI ID:20779226

Yiyi, Wang; Oezcan, Ahmet S; Ludwig, Jr, Karl F; Bhattacharyya, Anirban; Moustakas, T D; Lin, Zhou; Smith, David J ^[1]

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1. Physics Department, Boston University, Boston, Massachusetts 02215 (United States)

Structures with incommensurate ordering along the [0001] direction are observed in wurtzite Al{sub 0.72}Ga{sub 0.28}N alloys grown by plasma-assisted molecular beam epitaxy on c-plane sapphire. Films grown in environments with group-III/N ratios greater than 1 exhibit ordered superlattice structures that are incommensurate with the wurtzite crystal lattice. In contrast, films grown under nitrogen-rich conditions exhibit ordered structures with a periodicity of four cation-N monolayers. The increasing complexity of the ordering with increasing Ga-rich growth environment suggests that the ordering is related to the presence of a Ga overlayer believed to exist on the surface of the growing film.

• OSTI ID: 20779226
• Journal Information: Applied Physics Letters, Vol. 88, Issue 18; Other Information: DOI: 10.1063/1.2201898; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM NITRIDES
CATIONS
CRYSTAL GROWTH
CRYSTAL LATTICES
GALLIUM ALLOYS
GALLIUM NITRIDES
MOLECULAR BEAM EPITAXY
NITROGEN
NITROGEN ADDITIONS
PERIODICITY
PLASMA
SAPPHIRE
SEMICONDUCTOR MATERIALS
SUPERLATTICES
THIN FILMS