Magnetic lens apparatus for use in high-resolution scanning electron microscopes and lithographic processes

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:872959

Crewe, Albert V ^[1]

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1. Dune Acres, IN

Disclosed are lens apparatus in which a beam of charged particlesis brought to a focus by means of a magnetic field, the lens being situated behind the target position. In illustrative embodiments, a lens apparatus is employed in a scanning electron microscopeas the sole lens for high-resolution focusing of an electron beam, and in particular, an electron beam having an accelerating voltage of from about 10 to about 30,000 V. In one embodiment, the lens apparatus comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. In other embodiments, the lens apparatus comprises a magnetic dipole or virtual magnetic monopole fabricated from a variety of materials, including permanent magnets, superconducting coils, and magnetizable spheres and needles contained within an energy-conducting coil. Multiple-array lens apparatus are also disclosed for simultaneous and/or consecutive imaging of multiple images on single or multiple specimens. The invention further provides apparatus, methods, and devices useful in focusing charged particle beams for lithographic processes.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• DOE Contract Number: FE02-86ER60437
• Assignee: Arch Development Corporation (Chicago, IL)
• Patent Number(s): US 6051839
• OSTI ID: 872959
• Country of Publication: United States
• Language: English

Related Subjects

magnetic
lens
apparatus
high-resolution
scanning
electron
microscopes
lithographic
processes
disclosed
beam
charged
particlesis
brought
focus
means
field
situated
target
position
illustrative
embodiments
employed
microscopeas
sole
focusing
particular
accelerating
voltage
10
30
000
embodiment
comprises
electrically-conducting
coil
arranged
axis
pole
piece
extending
space
surrounded
dipole
virtual
monopole
fabricated
variety
materials
including
permanent
magnets
superconducting
coils
magnetizable
spheres
needles
contained
energy-conducting
multiple-array
simultaneous
consecutive
imaging
multiple
images
single
specimens
provides
methods
devices
useful
particle
beams
scanning electron
superconducting coils
magnetic lens
electron microscope
superconducting coil
particle beam
apparatus comprises
charged particles
permanent magnet
magnetic field
electron beam
permanent magnets
charged particle
particle beams
lens apparatus
provides apparatus
apparatus comprise
multiple images
target position
conducting coils
electron microscopes
illustrative embodiment
pole piece
accelerating voltage
magnetic pole
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