Patents by Inventor Albert V. Crewe
Albert V. Crewe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6410923Abstract: Disclosed are lens apparatus in which a beam of charged particles is 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 microscope as 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.Type: GrantFiled: April 17, 2000Date of Patent: June 25, 2002Assignee: Arch Development CorporationInventor: Albert V. Crewe
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Patent number: 6051839Abstract: 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.Type: GrantFiled: March 9, 1998Date of Patent: April 18, 2000Assignee: Arch Development CorporationInventor: Albert V. Crewe
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Patent number: 5563415Abstract: A lens apparatus in which a beam of charged particles of low accelerating voltage is brought to a focus by a magnetic field, the lens being situated behind the target position. The lens 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. The lens apparatus comprises the sole focusing lens for high-resolution imaging in a low-voltage scanning electron microscope.Type: GrantFiled: June 7, 1995Date of Patent: October 8, 1996Assignee: Arch Development CorporationInventor: Albert V. Crewe
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Patent number: 5336891Abstract: A system for reducing aberration effects in a charged particle beam. The system includes a source of charged particles, such as electrons or ions, and various building blocks for operating on the charged particle beam to generate a desired particle beam pattern. These building blocks can include at least one of a uniform magnetic field component and a uniform electrostatic field component arrangeable in different combinations, enabling coefficients of spherical and chromatic aberration to be canceled out thereby providing a charged particle beam having greatly diminished aberration.Type: GrantFiled: June 16, 1992Date of Patent: August 9, 1994Assignee: ARCH Development CorporationInventor: Albert V. Crewe
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Patent number: 5150001Abstract: An electron beam system comprises a vacuum enclosure, a source of electrons within the enclosure, and a passive pump located within or in communication with the enclosure for pumping gases from the enclosure. A supplemental active pump is coupled to the vacuum enclosure and functions simultaneously with the passive pump for pumping from the enclosure gases not removed, or not removed efficiently, therefrom by the passive pump.Type: GrantFiled: April 10, 1990Date of Patent: September 22, 1992Assignee: Orchid One CorporationInventor: Albert V. Crewe
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Patent number: 5008549Abstract: A high performance, vacuum compatible electromagnetic electron lens coil for electron beam systems has reduced gaseous emissions and improved heat dissipation capability. It comprises a wound coil of electrically conductive wire sheathed in a selected thermoplastic resin insulator. The wire insulator is coated with a hermetic layer of low vapor pressure metal. The low vapor pressure and hermetic sealing properties of the layer provide ultra high vacuum compatibility of the coil. The high thermal conduction property of the layer provides high heat dissipation capability and therefore permits high current densities in the coil.Type: GrantFiled: April 10, 1990Date of Patent: April 16, 1991Assignee: Orchid One CorporationInventor: Albert V. Crewe
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Patent number: 4833362Abstract: An encapsulated high brightness source for use in or with an electron beam system such as an electron beam microscope. The source preferably includes a field emitter. The source includes source enclosure means which defines an ultra high vacuum enclosure for the field emitter. A lens which serves as part of the ultra high vacuum enclosure for the source defines a differential pressure aperture. Other lens elements draw electrons from the field emitter and form a focus on axis in the vicinity of the differential pressure aperture, which serves as an effective point source for the associated electron beam system. The source may be permanently built-in or modular; if modular, it may be assembled, tested, and stored in an ultra high vacuum operative condition for OEM assembly or as a replacement part.Type: GrantFiled: April 19, 1988Date of Patent: May 23, 1989Assignee: Orchid OneInventor: Albert V. Crewe
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Patent number: 4760567Abstract: A rapid random accessed electron beam memory system comprises a disc mounted for rotation and supporting an information storage medium. An electron gun is mounted for movement across the disc. The gun has ultra-compactness and extremely low mass, yet is capable of developing a finely focused electron beam probe at high beam current densities. The gun comprises a low-mass field emission cathode, the cathode having an emitting tip and being adapted to receive a predetermined electrical potential to form a high brightness electron source at the tip. An electrostatic focus lens forms a real image of the electron source in the vicinity of the storage medium. The lens comprises a first electrode adapted to receive a predetermined second electrical potential which is positive relative to the potential on the tip and has a value effective to extract electrons from the tip. The electrode defines a relatively small aperture for deforming the diameter of an electron beam which is formed.Type: GrantFiled: August 11, 1986Date of Patent: July 26, 1988Assignee: Electron Beam MemoriesInventor: Albert V. Crewe
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Patent number: 4740705Abstract: An axially compact field emission cathode assembly for use in an electron beam device comprises a field emission tip, an electriclly conductive filament for mechanically supporting said tip and for receiving and conducting to said tip a predetermined electrical potential for exciting said filament to cause electron emission from said tip. Filament support means supports the filament with the tip positioned on an electron beam axis within said device. The cathode assembly is characterized by the filament being supported by said filament support means to extend transversely to the electron beam axis, whereby to reduce the axial length of the device.Type: GrantFiled: August 11, 1986Date of Patent: April 26, 1988Assignee: Electron Beam MemoriesInventor: Albert V. Crewe
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Patent number: 4725736Abstract: An ultra-compact electrostatic electron gun includes integrated beam-modifying means for use in electron beam memory systems, electron microscopes, electron lithographic devices and the like. The gun is illustrated as comprising means forming a point source of electrons and means receiving electrons from the point source for defining an electron beam. Electrostatic lens means receives the beam and forms a beam focus. An integrated magnetic field-generating means establishes a field of magnetic flux through the electrostatic lens for modifying the position, cross-sectional shape or other characteristic of the beam.Type: GrantFiled: August 11, 1986Date of Patent: February 16, 1988Assignee: Electron Beam MemoriesInventor: Albert V. Crewe
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Patent number: 4414474Abstract: Means for compensating for third and higher order aberrations in an electron optic system comprises two sextupoles and a field lens, the latter being spaced intermediate the sextupoles. The resolving power of the optic system can be reduced to the range of about 0.5 Angstrom unit.Type: GrantFiled: February 17, 1982Date of Patent: November 8, 1983Assignee: University Patents, Inc.Inventor: Albert V. Crewe
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Patent number: 4389571Abstract: A means is provided for compensating for third and higher order aberration in charged particle beam devices. The means includes two sextupoles with an intermediate focusing lens, all positioned between two focusing lenses.Type: GrantFiled: April 1, 1981Date of Patent: June 21, 1983Assignee: The United States of America as represented by the United States Department of EnergyInventor: Albert V. Crewe
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Patent number: 4303864Abstract: A means is provided for compensating for spherical aberration in charged particle beam devices. The means includes a sextupole positioned between two focusing lenses.Type: GrantFiled: October 25, 1979Date of Patent: December 1, 1981Assignee: The United States of America as represented by the United States Department of EnergyInventors: Albert V. Crewe, David A. Kopf
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Patent number: 4101813Abstract: A double deflection scanning system for electron beam instruments is provided embodying a means of correcting isotropic coma, and anisotropic coma aberrations induced by the magnetic lens of such an instrument. The scanning system deflects the beam prior to entry into the magnetic lens from the normal on-axis intersection of the beam with the lens according to predetermined formulas and thereby reduces the aberrations.Type: GrantFiled: April 14, 1977Date of Patent: July 18, 1978Assignee: The United States of America as represented by the United States Department of EnergyInventors: Norman W. Parker, Steven D. Golladay, Albert V. Crewe