SUPERCONDUCTING FLUX-COUPLED FAST SWITCHING DEVICE FROM YBCO FILMS ON SILICON

APPLICATIONS OF HIGH-TEMPERATURE SUPERCONDUCTING MATERIALS TO TUNNELING DEVICES HAVE BEEN LIMITED BY FABRICATION PROBLEMS RELATED TO THE INTRINSIC ANISOTROPY OF THESE MATERIALS, TO THEIR EXTREMELY SHORT SUPERCONDUCTING COHERENCE LENGTH, AND TO THE POOR ELECTRICAL PROPERTIES OF THE NATIVE SURFACE OXIDE ON THE YBA2CUO7-X (YBCO) FAMILY OF HTSC MATERIALS. MAGNETIC FLUX-COUPLED SWITCHING DEVICES MAY BE LESS LIMITED BY THE PROBLEMS JUST DESCRIBED. THE INNOVATION FOR THIS PROPOSAL IS TO DEMONSTRATE A FLUX-COUPLED SWITCHING DEVICE USING TWO RECENT ADVANCED BY THE PRINCIPAL INVESTIGATOR. IT IS PROPOSED HERE TO DEMONSTRATE A PARTICULAR DESIGN FOR A FLUX-COUPLED THIN-FILM SWITCHING DEVICE UTILIZING THE NEW PULSED-LASER DEPOSITION SYNTHESIS ROUTE TO EPITAXIAL, HIGH CRITICAL-CURRENT YBCO FILMS ON YSZ-BUFFERED SILICON SUBSTRATES. THE USE OF SI WAFERS AS SUBSTRATES WILL NOT ONLY ALLOW VERY HIGH QUALITY FILMS BUT ALSO MANY NEW DESIGN CONFIGURATIONS EMPLOYING HTSC SWITCHING DEVICES USEFUL FROM DC TO MICROWAVE. IN PARTICULAR, WE WILL FIRST FORM SIMPLE CONTACT BONDED PAIRS OF FILM-COATED SI WAFERS AND EVALUATE THEIR FLUX COUPLING PROPERTIES, AND THEN PASSIVATE THE YBCO FILM SURFACES AND BOND PAIRS OF THESE WAFERS WITH POLYMER ADHESIVES.