HTSC devices fabricated by selective epitaxial growth

The use of a selective epitaxial growth technique for fabricating YBCO thin -film microstructures is described. No film post-deposition processing is r equired; hence damage to the structure is minimized. The technique is compa tible with a passivation process to protect the structure without exposure to air. The microbridges, Josephson junctions and rf SQUIDs protected by an amorphous YBCO passivation have long lifetime even after severe accelerate d aging tests. Rf SQUIDs fabricated by this technique show a significant re duction of low-frequency noise when operating in weak magnetic fields compa red with SQUIDs fabricated by the conventional ion beam etching technique.