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Fabrication of Compact Josephson Edge Junction Interferometer

IP.com Disclosure Number: IPCOM000052277D
Original Publication Date: 1981-May-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Mohr, TO: AUTHOR [+3]

Abstract

This article describes a Josephson Edge junction Interferometer structure that yields very compact devices and that can be fabricated in a process requiring fewer process steps. This is accomplished by a design which permits the definition of both the base electrode and the insulator in the same etching process provided that electrode and insulator materials of suitable etch rate are chosen. The interferometer can be fabricated as follows: - A suitable substrate is covered with the superconductor base electrode material S1 (e.g., Nb) and, thereafter, with an insulator (e.g., Nb(2)O(5) or Si). - After applying a photoresist layer, the desired pattern is written and developed. This results in the structure of Fig. 1. - In a suitable plasma (e.g.

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Fabrication of Compact Josephson Edge Junction Interferometer

This article describes a Josephson Edge junction Interferometer structure that yields very compact devices and that can be fabricated in a process requiring fewer process steps. This is accomplished by a design which permits the definition of both the base electrode and the insulator in the same etching process provided that electrode and insulator materials of suitable etch rate are chosen. The interferometer can be fabricated as follows: - A suitable substrate is covered with the superconductor base electrode material S1 (e.g., Nb) and, thereafter, with an insulator (e.g., Nb(2)O(5) or Si). - After applying a photoresist layer, the desired pattern is written and developed. This results in the structure of Fig. 1. - In a suitable plasma (e.g., CF(4) with 0(2)) the resist, insulator and S1 are etched to give the structure of Fig. 2. For this process the materials may be chosen such that, for the plasma used, the etch rate of the resist is higher than that of the insulator whereas that of S1 is equal or still lower than that of the insulator. - After stripping, the remaining resist standard processes are used to clean and oxidize S1 (to form the tunnel barrier for the edge junctions) and to deposit and pattern the super conductor counter electrode 52. The completed interferometer is shown in Fig. 3.

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