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Fabricating Stable Josephson Junction Structures

IP.com Disclosure Number: IPCOM000084174D
Original Publication Date: 1975-Sep-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Chou, NJ: AUTHOR [+4]

Abstract

A process whereby pure In(2)O(3) films are grown on lead-indium alloys, so that stable Josephson junction structures can be fabricated is described hereinbelow.

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Fabricating Stable Josephson Junction Structures

A process whereby pure In(2)O(3) films are grown on lead-indium alloys, so that stable Josephson junction structures can be fabricated is described hereinbelow.

It is known that the junction device fabricated on Pb-In alloy base electrodes usually exhibit detrimental aging effects during the room temperature storage, or after an annealing treatment. The aging mechanism has been found to be attributable to the gradual conversion of PbO into pure In(2)O(3) in the junction insulator via a solid-state reaction at the alloy-insulator interface. The proposed process consists of the following steps: 1) Oxidation of Pb-In alloy in a UHV system at low-oxygen pressures (preferably < 5 x 10/-6/ torr); 2) Evacuation of the system to arrest further oxidation in the 10 torr range; and 3) Heating of the substrate in vacuum to convert the oxide film into pure In(2)O(3).

The above sequence may be repeated to obtain pure In(2)O(3) films of desired thickness.

In addition to the stability of device characteristics, the use of pure In(2)O(3)junction barrier has the advantage of having higher tunnel conductance, thus reducing the effect of insulator thickness fluctuation on device characteristics.

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