EXCIMER-LASER PROCESSING FOR SURFACE IMPROVEMENT OF TIN OXIDE THIN-FILMS

Results are presented on the processing of tin oxide films using an excimer laser. Commercially available films of SnO2 deposited on glass substrates were treated using a KrF excimer laser (248 nm). The results of these treatments were characterized by normal optical absorption, transmittance, and reflectance measurements in the VIS-NIR region along with x-ray diffraction and electrical conductivity measurements and a scanning electron microscopy (SEM) study. These were compared to the nontreated samples. The results inferred a relation between the amount of photoablated material with laser fluence, up to saturation. The optical spectroscopy results and the SEM study evidence modifications of the treated surface. On the other hand, the x-ray analysis indicates that the crystal structure is not altered by the laser treatment but the film morphology is. Furthermore, an increase of 15% and better in the normalized integrated optical transmittance in the visible region was obtained with this treatment, without changing the film electrical conductivity.