MASS-SPECTROMETRIC INVESTIGATION OF THE KRF LASER-INDUCED PLASMA PLUME CREATED ABOVE AN YBACUO SUPERCONDUCTING TARGET - CORRELATION WITH THICKNESS DISTRIBUTION OF DEPOSITED THIN-FILMS

The plasma plume created during the ablation of YBaCuO superconducting targets by a KrF laser beam (248 nm) is studied by mass spectrometry so as to understand one of the key-points of this thin films elaborati on technique, that is to say the transport of yttrium, barium, copper and oxygen species to the substrate. The evolutions of the relative co ncentrations of the detected species are reported as functions of the laser fluence on the target surface. The angular distribution of eject ed species is measured and fitted by cos(n) curves. The results, corre lated with thickness, allow an estimation of the relative contribution s of neutral and ionic species in deposited thin films.