Commercial Scale Production of High Temperature
Abstract
Thin films of YBa2Cu3O(7-x) were deposited onto substrates of up to three inch diameter by RF planar magnetron sputtering from an 8 inch diameter Y- Ba-Cu-O target. By locating the substrate above the center of the magnetron erosion ring and by placing a 'negative ion shield' between the substrate and the target, negative ion effects are avoided. A large area, backside radiant heater brings the bare substrates up to the temperatures necessary for in situ growth of superconducting YBa2Cu3O(7-x) films. The YBCO sputter deposition is completely automated and a throughput of 10 two inch diameters per week from a single target is easily achieved. YBCO films have been grown on MgO and LaAlO3 substrates with critical temperature > or = 90 K, change of temperature < 1 K, and critical current density > 1 million A/sq cm at 77 K. Microwave resistance for YBCO films on two inch diameter LaAlO3 substrates has been measured and found to be < 0.62 milliohms with a uniformity of better than + or - 5%. On two inch diameter substrates, uniformity of thickness and room temperature resistivity of < 7% have been achieved. The compositional uniformity of Y, Ba, and Cu across a two inch diameter substrate was found to be better than + or - 1%. Preliminary work on the growth of Y-ZrO2 dielectric layers and epitaxial YBCO/PLZT bilayers has been initiated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 14, 1991
- Accession Number
- ADA244355
Entities
People
- Paul Ballentine