Annealing effect on the reproducibility of Josephson Junctions made by ion irradiation

We have studied the annealing effects on the transport properties of High Tc Josephson Junctions (JJ) made by ion irradiation. Several JJ were measured for different annealing times and the experimental data were compared to numerical simulations. We have successfully used a vacancy-interstitial annihilation mechanism to describe the evolution of the JJ coupling temperature (TJ) and the homogeneity of a JJ array, related to the evolution of the defects density mean value and its distribution width. For sufficient long annealing times (t > 600 min), ΔTJ was significatively reduced. This result appears to be very encouraging for future applications where the spread in JJ characteristics has to be as low as possible.