Published in Appl. Phys. Lett. 79, 3428 (2001).
Role of Ga-flux in dislocation reduction in GaN films grown on SiC(0001)
C. D. Lee,* Ashutosh Sagar,* R. M. Feenstra,*
C. K. Inoki,** T. S. Kuan,**
W. L. Sarney*** and L. Salamanca-Riba***
*Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
**Department of Physics, University at Albany, SUNY, Albany, NY 12222
***Materials and Nuclear Engineering Department, University of Maryland, College Park, MD 20742-2115
GaN films are grown by plasma-assisted molecular beam epitaxy on SiC
substrates. The width of the x-ray rocking curve for the (1 0 -1 2)
reflection exhibits a distinct minimum for Ga/N flux ratios which are
only slightly greater than unity. Correlated with this minimum the surface
morphology is somewhat rough, with a hill and valley topography. Based on
transmission electron micrographs, the reduction in rocking curve width
is attributed to enhanced annihilation of edge dislocations due to their
tendency to cluster at topographic valleys.
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