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Laser Aided Fabrication Process for window Josephson Junctions

IP.com Disclosure Number: IPCOM000045706D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Marks, RF: AUTHOR [+2]

Abstract

A laser can be used to selectively remove thick oxides during device fabrication. For example, Nb(2)0(5) can be selectively removed with a laser prior to formation of a Josephson junction.

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Laser Aided Fabrication Process for window Josephson Junctions

A laser can be used to selectively remove thick oxides during device fabrication. For example, Nb(2)0(5) can be selectively removed with a laser prior to formation of a Josephson junction.

The fabrication of window josephson junctions includes the following steps:
(1) base electrode lithography, (2) base electrode deposition, (3) lithography to define windows, (4) thick oxide deposition, (5) tunnel barrier formation, and (6) counter electrode deposition.

Laser radiation can be used to form the windows in the thick oxide, eliminating the need for Step 3 above. The thick oxide layer produced in Step 4 can be selectively removed in regions exposed to laser light to produce window openings in the oxide. An ultra-clean surface is exposed in the window regions on which to proceed with Steps 5 and 6. The size of the windows can be controlled by changing the size of the laser beam. We have demonstrated that we can form a window through Nb(2)0(5) on Nb.

As described in a previous article (*), after forming the window, the laser can also be used at lower power levels to form the tunnel barrier.

Another advantage of using the laser to form the window is that the entire junction can be formed in one controlled environment.

Reference (*) P. Avouris, R. F. Marks, R. A. Pollak and Y. J. Thefaine, "Process for Controlled Thin Film Chemical Compound

Formation at and Removal from Solid Surfaces," IBM

Technical Disclosu...