GROWTH OF SIC AND SICXNY FILMS BY PULSED-LASER ABLATION OF SIC IN AR AND N-2 ENVIRONMENTS

Amorphous SiC and SiCxNy films have been deposited by pulsed laser dep osition on single crystal silicon substrates by KrF (248 nm) excimer l aser ablation of a SiC sintered target in a vacuum system at room temp erature using nonreactive, Ar, and reactive, N-2, background gases at different pressures. The pressure range in the growth chamber was from 4x10(-8) Torr to 80 mTorr. The optical properties and stoichiometry o f films were varied by the introduction of a background gas. The resul ting films are inspected by spectroellipsometry in the photon-energy r ange of 1.5<hv <5.0 eV. In situ high resolution x-ray photoemission sp ectroscopy characterization was performed on every film to obtain the atomic concentration and bonding constitution of the elements as a fun ction of background gas pressure. The ideal stoichiometry for SiC film s was obtained at Ar pressures higher than 30 mT. The existence of a n ew phase, given by SiCN2, was suggested from surface techniques and el lipsometric data in the deposition of SiCxNy films at N-2 pressures hi gher than 30 mTorr. (C) 1998 American Vacuum Society.