SiC xN y thin films alloys prepared by pulsed excimer laser deposition

Abstract

In this work, thin films of SiCN have been deposited by pulsed laser deposition on silicon substrates by KrF (248 nm) excimer laser ablation of a SiC sintered target in a vacuum system at room temperature. To obtain various stoichiometries, molecular nitrogen is introduced in the deposition chamber in the 5 to 500 mTorr pressure range. The resultant SiC x N y films are compared to the one prepared in a high vacuum environment (no N 2 gas). The film growth was monitored by real-time kinetic ellipsometry at a single photon-energy (2.5 eV). The film was analyzed by spectro-ellipsometry in the photon-energy range of 1.5< hv<5.0 eV at the end of the deposition process. Tauc's plots are used to estimate the optical band-gap of the films as a function of the N 2 gas pressure. High resolution in situ X-ray photoelectron spectroscopy characterization was performed on every film. The bonding character of the elements in the films is obtained by deconvoluting the XPS peaks. The ellipsometric and XPS results suggest that a new phase alloy is present in the SiC x N y films.