JAWS-SNAP refractory logic circuits

We describe a Josephson integrated circuit technology based on Nb-aSi-Nb tunnel junctions patterned by the selective niobium anodization process (SNAP). This technology also uses Mo resistors, bias-sputtered SiO2insulators, and Nb wiring to complete circuits of the direct current-injection variety using only five photolithographic steps. We have fabricated and tested chains of JAWS "OR" gates produced with this process. Proper operation is obtained for supply and offset currents varying by ± 20% (FANOUT = 1) and ± 10% (FANOUT = 2). This is in good agreement with calculations.