YBA2CU3OX - MICROSTRUCTURES ON SEMICONDUCTOR SUBSTRATES

Thin films of YBa2Cu3O(x) are prepared by laser ablation with a KrF excimer laser on Si and GaAs. These films show degraded superconducting properties compared to our films on SrTiO3 which exhibit critical temperatures T(c0) = 89 K and critical current densities J(c)(77 K) in the 10(6) A/cm2 range. Critical temperatures of 57 K and 30 K for films on Si and GaAs, respectively, could be achieved. On SrTiO3 we prepare YBa2Cu3Ox microbridges with widths down to 10-mu-m by wet chemical etching or by laser ablation through metal masks. Patterning of films on bare Si, however, is complicated by microcracks in the film due to different lattice constants and thermal expansion coefficients of Si and YBa2Cu3Ox. These problems may be overcome by the use of buffer layers whose influence on the film quality is also studied here.