Browse Prior Art Database

Device Based On Superconducting Material for Improving the Performance Of Electron-Optical Systems

IP.com Disclosure Number: IPCOM000121236D
Original Publication Date: 1991-Aug-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 81K

Publishing Venue

IBM

Related People

Batchelder, J: AUTHOR [+4]

Abstract

This article describes an improved method based on the use of superconducting materials for shielding an electron-optical system, such as a scanning electron microscope (SEM), transmission electron microscope (TEM) or electron beam fabrication machine (EBFM) or any other form of electron-optical system from the harmful effects of external magnetic fields, and for the use of such materials to control magnetic fields so as to focus the electrons in such systems.

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Device Based On Superconducting Material for Improving the Performance
Of Electron-Optical Systems

      This article describes an improved method based on the
use of superconducting materials for shielding an electron-optical
system, such as a scanning electron microscope (SEM), transmission
electron microscope (TEM) or electron beam fabrication machine (EBFM)
or any other form of electron-optical system from the harmful effects
of external magnetic fields, and for the use of such materials to
control magnetic fields so as to focus the electrons in such systems.

      In electron-optical systems, a high spatial resolution is
achieved either by means of a finely focused electron beam (EB), or
by an electron image.  This will not work if the electrons are
deflected through excessive angles by unwanted interfering magnetic
fields.  These interfering fields commonly come from outside the
apparatus and are, therefore, sometimes referred to as "external"
magnetic fields.  These fields can be kept out of the apparatus to
some extent by magnetic shields made from magnetic material.
Alternatively, it is well- known that magnetic shields can be made
from superconducting material cooled to essentially the temperature
of liquid helium.

      A second use of superconducting materials is to control
magnetic fields so as to focus the electrons in such systems.

      Recently, materials such as YBa2Cu3O9-z (also called "high Tc
material") have been discovered that are superconducting at the tem
perature of liquid nitrogen or above.  This invention teaches the use
of such materials in electron-optical systems which are now practical
because it is a much easier proposition to cool system components to
the temperature of liquid nitrogen, rather than to the temperature of
liquid helium.

      A simple experiment to demonstrate the use of these materials
to shield an electron-optical system from the harmful effects of
external magneti...