ALN THIN-FILMS DEPOSITION BY LASER-ABLATION OF AL TARGET IN NITROGEN REACTIVE ATMOSPHERE

Crystalline AIN thin films were deposited by laser ablation of high pu rity Al target in nitrogen reactive atmosphere. An YAG laser (lambda=1 .06 mu m, t(FWHM)=10 ns, 0.3 J/pulse), was used as laser source. The m aterial was collected on (100) and (111) Si wafers, The target collect or distance was varied in the range 3-6 cm, the nitrogen pressure was set in the range of 10(-3)-10(-1) mbar, the collectors were heated at different temperatures between 20 and 350 degrees C. The influence of the process parameters on the physical and piezoelectric properties of the deposited films was analyzed. X-ray diffraction studies revealed different crystalline orientation depending on deposition conditions: collectors temperature, position and orientation, reactive gas pressur e, incident laser fluence. The profile of Al and N atoms inside the fi lm were characterized by SIMS analysis. Small oxygen traces are presen t at collector-film interface. Depth profile X-ray photoelectron spect roscopy confirms the existence-in particular experimental conditions-o f only Al-N bonds inside the film.