FABRICATION OF STACKED INTRINSIC JOSEPHSON-JUNCTIONS FROM BI2SR2CACU2O8-FILMS(X THIN)

Stacked series arrays of intrinsic Josephson junctions were fabricated from Bi2Sr2CaCu2O8+x thin films, deposited by high-oxygen-pressure de sputtering. Stacks with areas between 2 x 2 mu m(2) and 50 x 50 mu m( 2), and thicknesses of 80-200 nm, were fabricated by photolithography and ion beam etching. We obtained RCSJ-like I-V curves with a critical current density of about 2 x 10(4) A cm(-2) at 4.2 K. At high bias cu rrents, we observed in some I-V curves many branches with gaps of abou t 10 mV corresponding to individual junctions. In addition, synchroniz ed switching of more than 10 junctions was observed.