Tunnel Area Definition After Tunnel Barrier Growth
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18
In processes presently employed to fabricate planar Josephson tunnel junctions, the junction areas are defined by a SiO window. The edges of the SiO layer cause disturbances that lead to excess currents and, in turn, to a large spread in Vm . These problems are avoided by the proposed process where the junction area is defined after barrier formation by a layer of a non-reactive material deposited on top of the barrier. The layer is sufficiently thin to permit tunneling therethrough. In the first step of the process, the junction is defined by a removable photoresist window, and the barrier is formed on the base electrode using conventional methods. Thereafter, a small amount of non-reactive material, like gold, is deposited on top of the barrier.