Sublimation in Growth of Aluminum Nitride-silicon carbide Alloy Crystals on SiC (001) substrates

Conference · Wed Jun 01 04:00:00 EDT 2005

OSTI ID:989516

Gu, Z ^[1]; Edgar, J H ^[1]; Payzant, E Andrew ^[2]; Meyer, III, Harry M ^[2]; Walker, Larry R ^[2]; Sarua, A ^[3]; Kuball, M ^[3]

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1. Kansas State University
2. ORNL
3. University of Bristol, UK

Thick (up to 1 mm) AlN-SiC alloy crystals were grown on off-axis Si-face 6H-SiC (0001) substrates by the sublimation-recondensation method from a mixture of AlN and SiC powders at 1860-1990 C in a N2 atmosphere. The color of the crystals changed from clear to dark green with increasing growth temperature. Raman spectroscopy and x-ray diffraction (XRD) confirmed an AlN-SiC alloy was formed with the wurtzite structure and good homogeneity. Three broad peaks were detected in the Raman spectra, with one of those related to an AlN-like and another one to a SiC-like mode, both shifted relative to their usual positions in the binary compounds, and the third with possible contributions from both AlN and SiC. Scanning Auger microanalysis (SAM) and electron probe microanalysis (EPMA) demonstrated the alloy crystals had an approximate composition of (AlN)0.75(SiC)0.25 with a stoichiometric ratio of Al:N and Si:C. The substrate misorientation ensured a two-dimensional growth mode confirmed by scanning electron microscopy (SEM).

• Research Organization: Oak Ridge National Laboratory (ORNL); High Temperature Materials Laboratory
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 989516
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
ALUMINIUM
CARBIDES
COLOR
ELECTRON PROBES
MICROANALYSIS
MIXTURES
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
SUBLIMATION
SUBSTRATES
X-RAY DIFFRACTION