Reproducible Current Density Josephson Junctions
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
Fabrication of Josephson tunnel junctions for integrated circuits require a process which provides precise control of the tunnel barrier. High quality Nb-Nb oxide-Pb alloy Josephson junctions are obtained by oxidizing the Nb with an RF plasma discharge using a dilute mixture of O(2) in Ar. However, junctions with reproducible current densities have been difficult to obtain using this process, even with careful control of the primary parameters: RF voltage, total gas pressure, Hb surface preparation, and oxidation time. This difficulty can be associated with such factors as the number of photoresist stenciled wafers mounted on the cathode, the solvents in the photoresist, and the general conditions in the oxidation chamber.