Composite Metallurgy Devices
Original Publication Date: 1980-Sep-01
Included in the Prior Art Database: 2005-Feb-13
This article relates to the use of a niobium-lead alloy composite base electrode for the formation of Josephson junction device structures. After the formation of the usual ground plane and ground plane insulation, the base electrode is formed by depositing through a photostencil a layer of niobium on the order of thousands of angstroms in thickness. Then, without breaking vacuum, a lead-indium-gold alloy film is deposited to a thickness on the order of hundreds of angstroms on the niobium layer. Alternatively, a new stencil is formed which confines the lead alloy deposition only to the junction area. This latter approach is preferable, for it permits the subsequent formation of a native oxide on the exposed niobium for insulation purposes.