SCANNING-TUNNELING-MICROSCOPY STUDY OF SINGLE-DOMAIN BETA-SIC(100) SURFACES - GROWTH AND MORPHOLOGY

We investigate single domain beta-SiC(100) thin film surfaces epitaxia lly grown on a vicinal (4 degrees) Si(100) surface by atom-resolved (f illed and empty states) scanning tunneling microscopy (STM). Contrary to previous beliefs, we observe high quality surfaces having a low den sity of defects. The beta-SiC(100)-(3 x 2) surface, which is a Si-rich surface; is achieved by sequences of Si deposition and surface anneal ings. This results in the growth and coalescence of large Si islands a nd/or vacancies islands having the 3 x 2 array. Our results indicate t he formation of asymmetric Si-Si dimers all tilted in the same directi on and forming rows in a 3 x 2 arrangement at a 1/3 Si monolayer cover age.