EFFECT OF BI2SR2CACU2OY SINGLE-CRYSTAL SURFACES ON CONTACT RESISTANCE

We formed Au electrodes on the surfaces of Bi2Sr2CaCu2Oy single crysta ls and investigated the effect of the surfaces on the contact resistan ce between Au electrodes and the single crystals. The lowest contact r esistivity was obtained by forming Au electrodes on the air-cleaved su rface of the Bi2Sr2CaCu2Oy single crystal, which is nearly equivalent to a clean surface. X-ray photoelectron spectroscopy results indicated that the contact resistances of the specimens were sensitive to the c hemical bond natures of the constituent elements on Bi2Sr2CaCu2Oy sing le crystal surfaces.