Effect of dislocations on electron mobility in AlGaN/GaN and AlGaN/AlN/GaN heterostructures

Journal Article · Mon Dec 24 04:00:00 EST 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4773510· OSTI ID:22089639

Kaun, Stephen W.; Burke, Peter G.; Kyle, Erin C. H.; Speck, James S. ^[1]; Wong, Man Hoi; Mishra, Umesh K. ^[2]

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1. Materials Department, University of California, Santa Barbara, California 93106 (United States)
2. Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)

Al{sub x}Ga{sub 1-x}N/GaN (x = 0.06, 0.12, 0.24) and AlGaN/AlN/GaN heterostructures were grown on 6 H-SiC, GaN-on-sapphire, and free-standing GaN, resulting in heterostructures with threading dislocation densities of {approx}2 Multiplication-Sign 10{sup 10}, {approx}5 Multiplication-Sign 10{sup 8}, and {approx}5 Multiplication-Sign 10{sup 7} cm{sup -2}, respectively. All growths were performed under Ga-rich conditions by plasma-assisted molecular beam epitaxy. Dominant scattering mechanisms with variations in threading dislocation density and sheet concentration were indicated through temperature-dependent Hall measurements. The inclusion of an AlN interlayer was also considered. Dislocation scattering contributed to reduced mobility in these heterostructures, especially when sheet concentration was low or when an AlN interlayer was present.

• OSTI ID: 22089639
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 26 Vol. 101; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
DISLOCATIONS
ELECTRON MOBILITY
GALLIUM NITRIDES
HALL EFFECT
HETEROJUNCTIONS
INCLUSIONS
LAYERS
MOLECULAR BEAM EPITAXY
SCATTERING
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
TEMPERATURE DEPENDENCE