FORMATION OF SUPERCONDUCTING NbN FROM Nb FILMS BY HIGH TEMPERATURE REACTION
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
NbN films can be formed by a high temperature reaction of Nb in a nitrogen atmosphere; however, both Nb film growth and reaction must be done in a single chamber. NbN is a desirable electrode material for superconducting devices because of its high Tc, large energy gap, and relatively low chemical reactivity. Pure NbN films are grown by reacting evaporated or sputtered Nb films at high temperature in a nitrogen atmosphere. This process, however, must be carried out inside a vacuum chamber, in order to avoid the formation of oxides on the Nb film. If the Nb film were to be air-transferred to another chamber for nitridation, the high temperature process would result in a detrimental relatively thick surface region consisting of oxygen dissolved in Nb along with suboxide and oxynitride phases.