TECHNOLOGY OF FABRICATION AND ELECTRICAL CHARACTERISTICS OF W, MO, NI AND IR, PD CONTACTS WITH YBA2CU3O7-X

The technology of fabrication and the properties of metallic electrical contacts on ceramics of YBa2Cu3O7-x superconductors have been studied. Contacts were deposited using the method of metal-organic chemical vapour deposition (MOCVD) for Ir, Pd and the method of exploding wires for W, Mo, Ni. The contacts, prepared by evaporation of Ir in oxygen atmosphere, have specific contact resistance rho-c of about 10(-5) OMEGA cm2. Since the temperature of deposition of contacts is 300-400-degrees-C (i.e. lower than 500-degrees-C, the temperature at which chemical interaction on the YBa2Cu3O7-x-Si, SiC, SiO2 boundary starts), such a technique can be incorporated into silicon-compatible technologies. It has been shown that good adhesion and specific contact resistivities of approximately 10(-2) OMEGA cm2 for W and Ni and approximately 10(-3) OMEGA cm2 for Mo can be achieved. After subsequent annealing rho-c reaches 10(-6), 7 x 10(-5), 7 x 10(-3) and 10(-2) OMEGA cm2 for Ir, Ni, W and Mo, respectively.