NOVEL CONTACT STRUCTURE FOR ULTRA-THIN YBA2CU3O7-X FILMS

Electrical contact structure for an ultra thin YBa2Cu3O7-x (YBCO) film was fabricated at edges of contact holes, which were made throughout the SrTiO3(STO)/YBCO film. Electrode of YBCO film, deposited st 600 de grees C by pulsed laser deposition method, was found to reduce contact resistance for the bottom YBCO film. The specific contact resistance (R-s) of 3 X 10(-8) Omega cm(2) was obtained from YBCO film of 5 nm th ick. YBCO deposition circumstances were considered to recover crystall inity of the bottom YBCO film adjacent to the contact hole edges. The ability of this process was comparatively evaluated with an ex situ pr ocess, which resulted in the R-s value of 5 X 10(-5) Omega cm(2) for Y BCO film of 5 nm thick. (C) 1998 Elsevier Science B.V. All rights rese rved.