LOW-PRESSURE CHEMICAL-VAPOR-DEPOSITION OF SILICON-CARBIDE THIN-FILMS FROM HEXAMETHYLDISILANE

Abstract

Silicon carbide thin films were grown by low pressure chemical vapor deposition using hexamethyldisilane Me3SiSiMe3 as the single-source precursor. Deposition of uniform thin films on Si(1 1 1) substrates was carried out at temperatures 1123-1323 K in a hot-wall reactor. The growth rates were 0.9-55 nm min-1 depending on the conditions employed. Estimated energy of activation is 110 kJ mol-1. Bulk elemental composition of the thin films, studied by an electron probe X-ray microanalyzer, is best described as SiC(x) (x = 0.8-2.3). The Si/C ratio increased with increasing temperature of deposition. The films were cubic polycrystals, a = 0.435-0.438 nm, as indicated by scanning transmission electron microscopy, electron diffraction and X-ray diffraction. The lattice parameter decreased with increasing temperature of deposition. Elemental distribution within the films, studied by Auger depth profiling and X-ray photoelectron spectroscopy, was uniform. Gas phase products H-2, CH4, C2H4, Me3SiH and Me4Si were identified and possible reaction pathways were proposed.