High mobility two-dimensional electron gases in nitride heterostructures with high Al composition AlGaN alloy barriers

Journal Article · Mon Nov 29 04:00:00 EST 2010 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3523358· OSTI ID:21518191

Guowang, Li; Yu, Cao; Grace, Xing Huili; Jena, Debdeep ^[1]

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1. Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

We report high-electron mobility nitride heterostructures with >70% Al composition AlGaN alloy barriers grown by molecular beam epitaxy. Direct growth of such AlGaN layers on GaN resulted in hexagonal trenches and a low mobility polarization-induced charge. By applying growth interruption at the heterojunction, the surface morphology improved dramatically and the room temperature two-dimensional electron gas (2DEG) mobility increased by an order of magnitude, exceeding 1300 cm{sup 2}/V s. The 2DEG density was tunable at 0.4-3.7x10{sup 13}/cm{sup 2} by varying the total barrier thickness (t). Surface barrier heights of the heterostructures were extracted and exhibited dependence on t.

• OSTI ID: 21518191
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 22 Vol. 97; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOY SYSTEMS
ALUMINIUM COMPOUNDS
CRYSTAL GROWTH METHODS
DENSITY
DIMENSIONS
ELECTRON GAS
ELECTRON MOBILITY
ELECTRONS
ELEMENTARY PARTICLES
EPITAXY
FERMIONS
GALLIUM COMPOUNDS
GALLIUM NITRIDES
HETEROJUNCTIONS
LAYERS
LEPTONS
MATERIALS
MOBILITY
MOLECULAR BEAM EPITAXY
NITRIDES
NITROGEN COMPOUNDS
PARTICLE MOBILITY
PHYSICAL PROPERTIES
PNICTIDES
POLARIZATION
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
SURFACES
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TERNARY ALLOY SYSTEMS
THICKNESS
TWO-DIMENSIONAL CALCULATIONS