Interaction of process parameters in the laser deposition of YBa2Cu3O7 films

Abstract The electrical and morphological properties of YBa 2 Cu 3 O 7 films grown on SrTiO 3 (100) substrates in a laser deposition process using a pulsed KrF excimer laser are investigated. For the first time, a quantitative order of importance of the relevant deposition parameters and their interactions that determine the quality of such films can be given. This is achieved by using statistical methods such as analysis of variance and multiple regression analysis for the design and evaluation of the experiments. The films prepared under optimum conditions grow c -axis oriented with low outgrowth densities and reveal transition temperatures T c ≅89 K, resistivities ρ (100 K )≤60 μ Ω cm, and resistance ratios R (300 K)/ R (100 K)≅3. The surface of the targets used for the deposition turned out to be crucial. Fresh targets yield significantly better electrical properties with a much lower spread of the data. Thus, a region in the process parameter space of YBa 2 Cu 3 O 7 film deposition has been identified where electrical and morphological properties are at optimum, simultaneously. This is prerequisite for the preparation of multilayer devices.