RAPID THERMAL CHEMICAL VAPOR-DEPOSITION GROWTH OF NANOMETER-THIN SIC ON SILICON

Rapid thermal chemical vapor deposition growth of beta-SiC ultrathin films on Si (100) was achieved using the carbonization reaction of the silicon substrate with C3H8 gas. Growth rates of 0.5-2 nm s-1 have been achieved at 1100-1300-degrees-C using C3H8 flow rates of 7-9 standard cm3 min-1. X-ray and electron diffraction indicate single-crystal epitaxial growth. Therefore nanometer-scale SiC films can be grown by controlling the reaction time to a few seconds. The activation energy at atmospheric pressure is 3.12 eV. The growth rate was found to decrease significantly at higher C3H8 flow rates, leading to films of constant thickness beyond a certain critical reaction time. Using this regime of self-limiting growth, SiC films of 3-5 nm have been grown with relatively little sensitivity to the growth time.