Polyimide Passivation for Making High-Tc Josephson Junctions

Passivation by coating with OCG285 (or equivalent) polyimide at critical steps of fabrication has been found to enhance the quality of tapered edges in high-critical-temperature (high-Tc) superconductor/normal-conductor/superconductor (SNS) Josephson junctions. In comparison with Josephson junctions that are nominally identical except for having been fabricated without such passivation, those fabricated with polyimide passivation exhibit cleaner and smoother edges and, consequently, smaller differences among the resistances and critical currents of individual junctions.