Growth and doping of Al{sub x}Ga{sub 1{minus}x}N deposited directly on {alpha}(6H)-SiC(0001) substrates via organometallic vapor phase epitaxy

Conference · Fri Nov 01 04:00:00 EST 1996

OSTI ID:394951

Bremser, M D; Perry, W G; Edwards, N V; Zheleva, T; Aspnes, D E; Davis, R F ^[1]; Parikh, N ^[2]

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1. North Carolina State Univ., Raleigh, NC (United States)
2. Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Physics and Astronomy

Monocrystalline Al{sub x}Ga{sub 1{minus}x}N(0001) (0.05 {le} x {le} 0.70) thin films, void of oriented domain structures and associated low-angle grain boundaries, have been grown at high temperatures via OMVPE directly on vicinal and on-axis {alpha}(6H)-SiC(0001) wafers using TEG, TEA and ammonia in a cold-wall, vertical, pancake-style reactor. The surface morphologies were smooth and the densities and distributions of dislocations were comparable to that observed in GaN(0001) films grown on high temperature AlN buffer layers. Double-crystal XRC measurements showed a FWHM value as low as 186 arc sec for the (0002) reflection. Spectra obtained via CL showed strong near band-edge emissions with FWHM values as low as 31 meV. The compositions of the Al{sub x}Ga{sub 1{minus}x}N films were determined using EDX, AES and RBS and compared to the values of the bandgap as measured by spectral ellipsometry and Cl emissions. A negative bowing parameter was found. Controlled n-type, Si-doping of Al{sub x}Ga{sub 1{minus}x}N for x {le} 0.4 has been achieved with net carrier concentrations ranging from {approx} 2 {times} 10{sup 17} cm{sup {minus}3} to 2 {times} 10{sup 19} cm{sup {minus}3}. Acceptor doping with Mg for x , 0.13 was also successful.

• OSTI ID: 394951
• Report Number(s): CONF-951155--; ISBN 1-55899-298-7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ALUMINIUM NITRIDES
AMMONIA
AUGER ELECTRON SPECTROSCOPY
CARRIER DENSITY
CHEMICAL VAPOR DEPOSITION
DISLOCATIONS
DOPED MATERIALS
ELECTRICAL PROPERTIES
ELECTRONIC EQUIPMENT
ELLIPSOMETRY
GALLIUM NITRIDES
HYDROGEN
MAGNESIUM
MICROSTRUCTURE
OPTICAL PROPERTIES
ORGANOMETALLIC COMPOUNDS
RUTHERFORD SCATTERING
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SURFACE CLEANING
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY