Large area deposition of YBCO-films by pulsed laser deposition for microwave applications

Pulsed laser deposition (PLD) was used to cover 2-inch-wafers of MgO and LaAlO3 with YBa2Cu3O7-x. The homogeneity of the YBCO-films concerning their structural and superconducting properties was proved by X-ray methods, RBS/channelling and spatially resolved inductive measurements of T-c and j(c). With regard to microwave applications the surface resistance R-s at 19 GHz was measured in a dielectric resonator. The film thickness and the c-axis length show no significant variations over the wafer diameter. The rocking curves of the (005) peak show only slight variations of the FWHM. The critical current density j(c) (77 K) of 2 ''-films range between 2-5 MA cm(-2), and the transition temperature T-c varies between 89.0 and 90.5 K. Surface resistance values at 19 GHz as low as 0.15 m Omega (4.2 K) and 0.8 m Omega (70 K) have been achieved which stay held-independent up to about 10 and 1 mT, respectively.