EXCIMER-LASER REACTIVE ABLATION DEPOSITION OF SILICON-NITRIDE FILMS

Silicon nitride films were deposited on silicon wafers by XeCl (308 nm) excimer laser ablation of silicon in low pressure (1 X 10(-3)-1 mbar) ammonia atmospheres. Series of 10 000 pulses at the repetition rate of 8 Hz were directed to the target surface. The fluence was set at about 5J/cm(2). Pulse duration was about 30 ns. The deposited films were characterized by different techniques (X-ray diffraction, infrared spectrophotometry, X-ray photoelectron spectroscopy, Auger electron spectroscopy, scanning electron microscopy, profilometry). Deposition of stoichiometric silicon nitride films with thickness close to 1 mu m (deposition rate similar to 0.1 nm/pulse) was obtained when ablation was performed in ammonia at the pressure of 1 mbar.