Growth of GaN(0001)1 times 1 on Al sub 2 O sub 3 (0001) by gas-source molecular beam epitaxy

Journal Article · Mon May 18 04:00:00 EDT 1992 · Applied Physics Letters; (United States)

DOI:https://doi.org/10.1063/1.106948· OSTI ID:7116118

Powell, R C; Lee, N; Greene, J E ^[1]

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1. Materials Science Department, the Coordinated Science Laboratory, and the Materials Research Laboratory, University of Illinois, 1101 West Springfield Avenue, Urbana, Illinois 61801 (United States)

Gas-source molecular beam epitaxy (GSMBE), utilizing Ga and NH{sub 3}, has been used to grow single-crystal GaN(0001)1{times}1 on Al{sub 2}O{sub 3}(0001) substrates at temperatures {ital T}{sub {ital s}} between 700 and 850 {degree}C. {ital In} {ital situ} reflection high-energy electron diffraction studies show a transition from three-dimensional to two-dimensional growth at {ital T}{sub {ital s}}{approx gt}770 {degree}C. For {congruent}1-{mu}m-thick GaN layers, the best room-temperature carrier mobilities, 100--110 cm{sup 2} V{sup {minus}1} s{sup {minus}1}, with carrier concentrations of 1--4{times}10{sup 18} cm{sup {minus}3}, were obtained at {ital T}{sub {ital s}}{ge}780 {degree}C. These are the highest reported mobilities for MBE GaN. Band-to-band photoluminescence was observed in these films at room temperature. Cross-sectional transmission electron microscopy showed that the primary defects in the films were threading dislocations, with Burgers vectors {ital a}{sub 0}/3{l angle}2{bar 1}{bar 1}0{r angle}, and stacking faults.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 7116118
• Journal Information: Applied Physics Letters; (United States), Journal Name: Applied Physics Letters; (United States) Vol. 60:20; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CARRIER DENSITY
CARRIER MOBILITY
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DIFFRACTION
DISLOCATIONS
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
EPITAXY
GALLIUM COMPOUNDS
GALLIUM NITRIDES
LINE DEFECTS
LUMINESCENCE
MICROSCOPY
MOBILITY
MOLECULAR BEAM EPITAXY
NITRIDES
NITROGEN COMPOUNDS
PHOTOLUMINESCENCE
PNICTIDES
SCATTERING
STACKING FAULTS