All-Nitride Superconducting Tunnel Junctions
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Three layers of niobium nitride/silicon nitride/niobium nitride form a superconducting tunnel junction with good control of electrode properties and minimal transition width. When a superconducting tunnel junction is fabricated, an oxidation with oxygen or air is always included as part of the tunnel barrier processing. The oxidations are used to form the tunnel barrier by oxidation of the base electrode. They are also necessary to oxidize underlying electrode metallurgy through pinholes in discontinuous barrier films, such as deposited semiconductors. The introduction of oxygen into the vacuum system introduces several process problems. A three-layer, all-refractory superconducting tunnel junction, composed only of nitride layers, avoids oxide process problems.