CONTINUED IMPROVEMENT OF LARGE AREA, IN SITU SPUTTER DEPOSITION OF SUPERCONDUCTING YBCO THIN FILMS

Thin films of superconducting YBa2Cu3O7-x have been deposited onto substrates up to three inches in diameter by an "integrated off-axis" sputter deposition technique. The substrate is located above the center of an 8 inch diameter YBCO planar target, and in conjunction with a "negative ion shield," ne r live ion effects are avoided. A large area radiant heater provides backside, noncontact heating of the bare substrates. YBCO films have been grown on polished 1 cm(2) MgO and LaAlO3 substrates with T-C >= 90 K, J(C) >= 2.5 x 10(6) A/cm(2) at 77 K, and microwave surface resistance R-S < 0.4 mil at 77 K and 10 GHz. The films have a very smooth surface morphology. Uniformity data for two-inch LaAlO3 substrates are less than +/- 5% in R-S. Thickness uniformity results for three inch substiates indicate less than 10% variation. The growth of epitaxial insulating films for use with YBCO films will be discussed, as will the application of the YBCO films in microwave devices.