Influence of pulse width and target density on pulsed laser deposition of thin YBaCuO Films

We have studied the effects of temporal pulse width and target density on the deposition of thin films of YBaCuO. A 248nm excimer laser and an 825nm Ti-sapphire laser were used to conduct the experiments with pulse widths of 27 ns, 16 ns, and 150 fs, and target densities of 80% and 90%. Scanning electron microscope photomicrographs and profilometer traces show a striking difference between nanosecond and femtosecond laser irradiation. Shortening the pulse width reduced particulate formation, provided stoichiometry, and improved the film properties. Decreasing the target density raised the ablation rate, produced thicker but nonuniform films, and reduced particulate formation.