Josephson contact tunnel layer - is produced in reactor on base electrode and followed by counter electrode without interruption

摘要

The quality of the tunnel layer in a Josephson contact depends on the undisturbed and extremely clean surface of the base electrode. This can be achieved by completing all operations without having to interrupt the vacuum. A window to suit the pattern of the base electrode is produced by photolithography in a layer (27) of photolacquer on a substrate (21). The superconducting base electrode (12) is vapour deposited in a vacuum reactor. The reactor atmosphere is now altered to suit a sputter etching operation to remove a slight amount of material from the electrode surface. The atmosphere is changed again to produce a tunnel layer (23) by glow discharge oxidation. The thin superconducting counter electrode (25) is finally vapour deposited in a high vacuum.