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We describe a technique using photolithography to produce submicron-scale thin-film structures and simple multilevel structures by single-mask lift-off processing. The technique employs masks offset from the substrate and oblique angle thin-film deposition. It provides a simple means of making small-area Josephson junctions and varying-thickness superconducting bridges and is suitable for the inclusion of these devices in circuits. The examples we show emphasize such applications in superconductivity; however, the technique may find uses in other fields as well.

Experiments on small superconducting tunnel junctions in a Giaever-Zeller-plus-SQUID geometry clearly show an I(V) feature due to Josephson super-current in a regime where single-electron charging effects are dominant. The I(V) data exhibit marked oscillations with gate voltage characteristic of single-electron charging. The Josephson feature shows both this effect and SQUID-related oscillations with applied magnetic field. The behavior can be understood through the usual model for charging effects in such circuits, extended to include two-electron transitions.

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