Growth of SiC and SiCxNy films by pulsed laser ablation of SiC in Ar and N2 environments

Abstract

Amorphous SiC and SiCxNy films have been deposited by pulsed laser deposition on single crystal silicon substrates by KrF (248 nm) excimer laser ablation of a SiC sintered target in a vacuum system at room temperature using nonreactive, Ar, and reactive, N2, background gases at different pressures. The pressure range in the growth chamber was from 4×10−8 Torr to 80 mTorr. The optical properties and stoichiometry of films were varied by the introduction of a background gas. The resulting films are inspected by spectroellipsometry in the photon-energy range of 1.5<hv<5.0 eV. In situ high resolution x-ray photoemission spectroscopy characterization was performed on every film to obtain the atomic concentration and bonding constitution of the elements as a function of background gas pressure. The ideal stoichiometry for SiC films was obtained at Ar pressures higher than 30 mT. The existence of a new phase, given by SiCN2, was suggested from surface techniques and ellipsometric data in the deposition of SiCxNy films at N2 pressures higher than 30 mTorr.