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Tunneling Device Using NbN

IP.com Disclosure Number: IPCOM000091117D
Original Publication Date: 1969-Nov-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+3]

Abstract

In this tunneling gate, the electrodes are niobium nitride Nbn. The thin insulator separating these superconducting electrodes is aluminum nitride AlN. Type II compound superconductors, such as NbN, are suited for Josephson devices because of their higher energy gap and recrystallization temperature. The NbN films are prepared by RF sputtering using a high-purity Nb cathode, presputtering from 15-30 minutes at 10 microns argon pressure, and sputtering in a 9:1 argon:nitrogen environment, with a substrate temperature of 450 degrees C. Suitable substrate materials are sapphire crystals. Thin film 1 of NbN is deposited on resist insulation 2 and then a thin layer, 10-50 angstroms, of AlN is deposited on the NbN. After this, another thin electrode 3 of NbN is sputtered over the AlN-NbN sandwich.

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Tunneling Device Using NbN

In this tunneling gate, the electrodes are niobium nitride Nbn. The thin insulator separating these superconducting electrodes is aluminum nitride AlN. Type II compound superconductors, such as NbN, are suited for Josephson devices because of their higher energy gap and recrystallization temperature. The NbN films are prepared by RF sputtering using a high-purity Nb cathode, presputtering from 15-30 minutes at 10 microns argon pressure, and sputtering in a 9:1 argon:nitrogen environment, with a substrate temperature of 450 degrees
C. Suitable substrate materials are sapphire crystals. Thin film 1 of NbN is deposited on resist insulation 2 and then a thin layer, 10-50 angstroms, of AlN is deposited on the NbN. After this, another thin electrode 3 of NbN is sputtered over the AlN-NbN sandwich. The control element can be any metal, such as lead, and is insulated from the Josephson gate by layer 4 of SiO or any other suitable insulator.

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