SUPERCONDUCTING TUNNEL JUNCTION PHOTODETECTOR AND MANUFACTURE THEREOF

摘要

PURPOSE:To form a homogeneous interface tunnel barrier substantially having no pinhole, and to realize high-speed response optical detection in an infrared region by shaping the resistive interface barrier forming a tunnel barrier between a lower electrode consisting of an oxide superconductor and an upper electrode composed of a normal conductive metal shaped onto the lower electrode. CONSTITUTION:At oxide superconductor thin-film is deposited on the whole surface on a substrate 1 made up of sapphire through sputtering. The typical composition of an oxide superconductor is represented by BaPb0.7Bi0.3O3 at that time. A lower, electrode 4 is formed through lithography and etching (b), Au is evaporated and an upper electrode 2 is shaped, and a tunnel junction type photodetector is manufactured (c). An interface tunnel barrier is formed on the interface of the upper electrode and the lower electrode by a redox reaction in the photodetector having such constitution. The tunnel resistance of the interface tunnel barrier can also be changed through heat treatment by proper heating.