SELECTIVE TRILAYER DEPOSITION PROCESS FOR FABRICATING Nb/Al-AlOx/Nb JOSEPHSON TUNNEL-JUNCTIONS

High quality Nb/Al-AlOx/Nb Josephson tunnel junctions have been fabricated using a novel process named the selective trilayer deposition process. The junction is formed on a patterned Nb underlayer through the lift-off deposition of a Nb/Al-AlOx/Nb trilayer. Anodization then provides the insulation between the underlayer and the wiring layer. We show that this easy and simple process is particularly advantageous for the fabrication of many vertically stacked tunnel junctions.