ZNO THIN-FILM DEPOSITION BY LASER-ABLATION OF ZN TARGET IN OXYGEN REACTIVE ATMOSPHERE

ZnO thin films were deposited by laser ablation of Zn target in oxygen reactive atmosphere. The films are crystalline, their c-axis is perpe ndicular to the substrate surface, they exhibit high optical transmiss ion (95% in the visible range, with a step transition at 380 nm), a ba nd gap value of 3.2 eV and a high piezoelectric coefficient. A YAG las er (lambda = 1.06 mu m, tau(FWHM) = 10 nS, 0.3 J/pulse), was used as l aser source. The material was collected on different substrates: Si wa fers, sapphire, Coming glass plates. The influence of the process para meters on the physical properties of the deposited films was studied. The target-collector distance was varied in the range 4-8 cm, the oxyg en pressure was set between 10(-3) mbar and 10(-1) mbar, the collector s were heated at different temperatures between 20 and 350 degrees C. Cross-section scanning electron microscopy, optical transmission spect ra, X-ray diffraction and electroacoustic studies were performed to ch aracterize the deposited films.