Effects of oxygen pressure and target-substrate distance on the density of particulates on pulsed laser deposited YBa_2Cu_3O_(7-x) thin film surfaces

摘要

The pulsed laser deposition process is one of the most promising methods for preparing high quality thin films of high Tc superconductors [1-5]. The versatility of this technique has been shown clearly in the multilayer in situ deposition of supercon-ducting superlattice structures [6], and of buffer layers between superconducting thin films and subs-trates such as Si and GaAs [7-9]. However, a significant drawback of the pulsed laser deposition technique is the presence of particulates at the film surface with typical size in the order of 1 /im. These particulates are very injurious to the growth of heteroepitaxial multilayers, the fabrication of pla-nar-type Josephson junctions and microwave surface resistance.