High-quality reproducible PLD Y–Ba–Cu–O:Ag thin films up to 4 inch diameter for microwave applications

Large-area pulsed laser deposition (PLD) has reached a state in terms of film quality and reproducibility which makes possible now real applications of PLD-YBa 2 Cu 3 O 7− δ (YBCO) thin films on both sides of R -plane sapphire substrates as HTSC devices in mobile communication systems. Bandpass filters optimized from PLD-YBCO thin films presently fulfill the requirements of the main national companies which are active in future communication techniques. A relatively simple PLD arrangement with fixed laser plume and rotating substrate, with an offset between the laser plume and the center of the substrate is employed to deposit laterally homogeneous 4 inch diameter Ag-doped YBCO thin films. With the experience of more than 1000 double-sided 3 inch diameter films a high degree of homogeneity and reproducibility of j c and R s is reached. The extension up to 8 inch substrate diameter will increase the productivity of the flexible PLD technique considerably.