Growth and characterization of AlGaN/GaN heterostructures on semi-insulating GaN epilayers by molecular beam epitaxy

Journal Article · Thu May 01 04:00:00 EDT 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2909188· OSTI ID:21137251

Mei, F; Fu, Q M; Peng, T; Liu, C ^[1]; Peng, M Z; Zhou, J M ^[2]

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1. Key Laboratory of Acoustic and Photonic Materials and Devices, Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan 430072 (China)
2. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080 (China)

Al{sub 0.30}Ga{sub 0.70}N/GaN heterostructures grown on sapphire substrates by rf-plasma-assisted molecular beam epitaxy are investigated. The heterostructures consist of a 20 nm Al{sub 0.30}Ga{sub 0.70}N barrier layer deposited on a 2 {mu}m semi-insulating GaN epilayer. Room-temperature mobilities averaging 1350 cm{sup 2}/V s and a sheet charge density of 1.1x10{sup 13} cm{sup -2} are consistently achieved. Central to our approach is the iron-doped semi-insulating GaN epilayer and a pulsed N/Ga atomic deposition technique which makes it possible to simultaneously reduce threading dislocations and achieve a smooth surface. The heterostructures were examined by x-ray diffraction, transmission electron microscopy, and atomic force microscopy. Structural characterizations reveal a smooth surface morphology, coherent and sharp interfaces, and a low density of the threading dislocations.

• OSTI ID: 21137251
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 103; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
ATOMIC FORCE MICROSCOPY
CARRIER MOBILITY
CHARGE DENSITY
CRYSTAL GROWTH
DEPOSITION
DISLOCATIONS
DOPED MATERIALS
GALLIUM NITRIDES
HETEROJUNCTIONS
INTERFACES
IRON
LAYERS
MOLECULAR BEAM EPITAXY
MORPHOLOGY
SAPPHIRE
SEMICONDUCTOR MATERIALS
TEMPERATURE RANGE 0273-0400 K
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION