GROWTH OF THIN BETA-SIC LAYERS BY CARBONIZATION OF SI SURFACES BY RAPID THERMAL-PROCESSING

The growth of thin SiC layers by carbonization via rapid thermal chemical vapour deposition at atmospheric pressure on Si(100) and Si(111) surfaces using propane (C3H8) and hydrogen (H-2) at 11 min(-1) as a carrier gas was investigated. The dependences of the growth kinetics, the crystal structure and the surface morphology of the SiC on C3H8 concentration and ramp rate were determined by reflection high energy electron diffraction, scanning electron microscopy and ellipsometry. No fundamental differences in growth kinetics were found between (100) or(111) substrates and n- or p-type Si. The propane concentration in the flowing gas shows the strongest influence on SiC thickness and morphology. The maximal layer thickness connected with a disturbed structure was maintained at 1330 degrees C and 0.025% C3H8. The best growth conditions regarding crystallinity were found at lower temperatures (1240 degrees C) and higher concentrations (above 0.1% C3H8). At long growth cycles above 60 s and concentrations greater than 0.6% C3H8 a graphite-like carbon phase on top of a single-crystal SIC layer occurred. Possible growth mechanisms were discussed. The observed ability of self-limited growth was used for large-area thin beta-SiC film growth.