Bi2Sr2CaCu2O8+delta intrinsic Josephson junctions fabricated by a simple technique without photolithography

Due to the roughness in the surface of the crystal sample, it is hard to us e photolithography in the patterning process of the Bi2Sr2CaCu2O8+delta int rinsic Josephson junction. In this gaper, we report a simple technique for fabricating the Bi2Sr2CaCu2O8+delta intrinsic Josephson junctions. In the p atterning process, metal masks are used instead of photolithography and arg on ion milling is applied to form a small mesa on the Bi2Sr2CaCu2O8+delta c rystal surface. Real four-probe transport measurements are made on the Bi2S TZCaCU208+6 intrinsic junctions and typical current-voltage characteristics with multi-branch structure have been observed, from which the superconduc ting gap parameter can be extracted, Additionally, from the strong hysteres is in the I-V characteristics, the capacitance C-J of the unit intrinsic Jo sephson junction can be estimated, which is in good agreement with that eva luated from the geometric parameters of the unit junction between the two c opper oxide layers.