Large area pulsed laser deposition of YBCO thin films

A special PLD-setup for large area deposition of homogeneous YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) thin films and buffer layers as large as 7 cm/spl times/20 cm is presented. A new concept for homogeneous large area substrate heating and the influence of the deposition rate on the film properties is discussed. YBCO is deposited on r-plane sapphire substrates (10 cm/spl times/10 cm) as well as on smaller (2 inch O, 1 cm/spl times/1 cm) SrTiO/sub 3/, MgO, LaAlO/sub 3/, and on yttria stabilized ZrO/sub 2/ substrates distributed over the deposition area. The homogeneity of the deposited YBCO films concerning structural and electrical properties is investigated by XRD, RBS/channeling, and spatially resolved inductive measurements of T/sub c/ and J/sub c/. The variation of J/sub c/ on a 2 inch MgO wafer is less than /spl plusmn/9%, the mean c-axis length is 11.681 /spl Aring/, the FWHMs of the [005] rocking curves are 0.40 and the channeling minimum yield /spl chi//sub min/ varies between 3.7% and 4.9% over the 2 inch wafer. The J/sub c/ values of YBCO on 7 cm x 20 cm in situ buffered sapphire substrates are (2.0/spl plusmn/0.4 MA/cm/sup 2/) at T=77 K and B=0 T.