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 chemi cal vapour deposition at atmospheric pressure on Si(100) and Si(111) s urfaces using propane (C3H8) and hydrogen (H-2) at 11 min(-1) as a car rier gas was investigated. The dependences of the growth kinetics, the crystal structure and the surface morphology of the SiC on C3H8 conce ntration and ramp rate were determined by reflection high energy elect ron diffraction, scanning electron microscopy and ellipsometry. No fun damental differences in growth kinetics were found between (100) or(11 1) substrates and n- or p-type Si. The propane concentration in the fl owing gas shows the strongest influence on SiC thickness and morpholog y. The maximal layer thickness connected with a disturbed structure wa s maintained at 1330 degrees C and 0.025% C3H8. The best growth condit ions regarding crystallinity were found at lower temperatures (1240 de grees C) and higher concentrations (above 0.1% C3H8). At long growth c ycles above 60 s and concentrations greater than 0.6% C3H8 a graphite- like carbon phase on top of a single-crystal SIC layer occurred. Possi ble growth mechanisms were discussed. The observed ability of self-lim ited growth was used for large-area thin beta-SiC film growth.