Browse Prior Art Database

Minimizing Degradation of Superconducting Properties

IP.com Disclosure Number: IPCOM000119688D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Clark, GJ: AUTHOR [+4]

Abstract

A technique is described whereby degradation of superconducting properties during fabrication is avoided, thereby allowing devices to operate above 77oK. The process concentrates on preventing the loss of oxygen during ion implantation.

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Minimizing Degradation of Superconducting Properties

      A technique is described whereby degradation of
superconducting properties during fabrication is avoided, thereby
allowing devices to operate above 77oK.  The process concentrates on
preventing the loss of oxygen during ion implantation.

      In the prior art, superconducting materials will lose oxygen at
high temperatures in a vacuum.  The rate of oxygen loss increases as
the heating increases, thereby degrading the material.  The
metallization and patterning process during device fabrication is not
considered responsible for the degradation in high temperatures.
Therefore, it is concluded that the fabricated devices have degraded
in high temperature because of a) ion implantation in a vacuum, and
b) heating during ion implantation which accelerates the oxygen loss.

      The concept described herein avoids superconducting material
degradation by carrying out the ion implantation necessary for
patterning the device in an atmosphere of oxygen.  It is
advantageous, but not necessary, to place the sample on a cold
substance to further minimize oxygen loss. When held at 77@K, the
oxygen will absorb on the sample face giving a high concentration of
surface molecule, i.e., a high local partial pressure of oxygen at
the surface, thereby preventing loss of oxygen from the sample.

      Possible processing configurations are shown in Figs. 1 and 2.
A third possible configuration may be required as sh...