Published in MRS Internet J. Nitride Semicond. Res. 5S1, W3.47 (2000).
TEM Study of the Morphology Of GaN/SiC (0001) Grown at Various
Temperatures by MBE
W. L. Sarney*, L. Salamanca-Riba*, V. Ramachandran**, R. M. Feenstra**,
D. W. Greve***
*Dept. of Materials & Nuclear Engineering, University of Maryland,
College Park, Maryland 20742-2115
**Department of Physics, Carnegie Mellon University,
Pittsburgh, Pennsylvania 15213
***Department of Electrical and Computer Engineering, Carnegie
Mellon University,
Pittsburgh, Pennsylvania 15213
Abstract
GaN films grown on SiC (0001) by MBE at various
substrate temperatures (600 - 750°C) were characterized by RHEED,
STM, x-ray diffraction, AFM and TEM. This work focuses on the TEM
analysis of the films' features, such as stacking faults and
dislocations, which are related to the substrate temperature. There
are several basal plane stacking faults in the form of cubic
inclusions for samples grown at low temperatures compared to those
grown at high temperatures. The dislocation density is greatest for
the film grown at 600°C, and it steadily decreases with increasing
growth temperatures. Despite the presence of various defects, x-ray
analysis shows that the GaN films are of high quality. The double
crystal rocking curve full width at half maximum (FWHM) for the GaN
(0002) peak is less than 2 arc-minutes for all of the films we
measured and it decreases with increasing growth temperature.
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