REDUCTION IN PARTICLE DENSITY OF LASER-DEPOSITED YBA2CU3O7 THIN-FILMSBY LOW-ENERGY ULTRAVIOLET-RADIATION

The effect of nanosecond pulsed excimer laser irradiation on the parti cle distribution and density of laser-deposited YBa2Cu3O7 thin films w as investigated. High-Tc YBa2Cu3O7 superconducting thin films with thi cknesses varying from 800 to 2000 Angstrom were deposited on (100) LaA lO3 and (100) yttria stabilized zirconia substrates. The as-deposited films were characterized by a distribution of particles on the film's surface. The effect of controlled low energy density pulses (fluence, E=50-250 mJ/cm(2), wavelength lambda=248-308 nm, and pulse duration ta u=20-45 X 10(-9) s) on these films was investigated. A significant red uction of particles was observed in films after single pulse irradiati on at fluences below 150 mJ/cm(2). Multiple pulses did not have any fu rther change on the surface morphology. The possible mechanisms for pa rticle removal are also discussed.