Effects of oxidation parameters on Josephson junction breakdown voltage, resistance-area variation and cryo performance

Optimizing qubit frequency targeting is crucial for developing large-scale superconducting quantum processors. One promising post-fabrication technique for precise qubit frequency tuning is alternating-bias assisted annealing (ABAA) technique, though its effectiveness can be limited by the breakdown voltage of Josephson junctions (JJs). The breakdown voltage is influenced by both junction size and barrier characteristics. Our study specifically investigates how oxidation parameters —including time, temperature, pressure, and O2 flow rate— impact the oxide barrier of JJs. We further analyze the resulting effects of these parameters on the breakdown voltage, RA (resistance x area) product, and cryogenic performance of the JJs.