Patents by Inventor Bruce W. Smith

Bruce W. Smith 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).

  • Patent number: 8852850
    Abstract: A photolithographic exposure system for use on a photoresist on a substrate includes an illumination system, a photomask with one or more object patterns, a projection optical exposure system, and a fluid dispensing system. The projection optical exposure system is positioned to project an image of the one or more object patterns toward an image plane. The fluid dispensing system positions a fluid between the projection optical exposure system and the photoresist on the substrate. The fluid has a refractive index value above a refractive index value of water and an absorbance below 0.8 per millimeter at wavelengths between about 180 nm and about 300 nm.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: October 7, 2014
    Assignee: Rochester Institute of Technology
    Inventor: Bruce W. Smith
  • Patent number: 7768648
    Abstract: Aberrations in an optical system can be detected and measured using a method comprised of a test target in the object plane of a projection system and imaging onto the image plane with the system. The test target comprises at least one open figure which comprises a multiple component array of phase zones, where the multiple zones are arranged within the open figure so that their response to lens aberration is interrelated and the zones respond uniquely to specific aberrations depending on their location within the figure. This is a unique and new method of detecting a variety of aberration types including coma, spherical, astigmatism, and three-point through the imaging onto photosensitive material or image detector placed in the image plane of the system and the evaluation of these images.
    Type: Grant
    Filed: November 14, 2006
    Date of Patent: August 3, 2010
    Inventor: Bruce W. Smith
  • Patent number: 7345735
    Abstract: Aberrations in an optical system can be detected and measured using a method comprised of a test target in the object plane of a projection system and imaging a photoresist film with the system. The test target comprises at least one open figure which comprises a multiple component array of phase zones, where the multiple zones are arranged within the open figure so that their response to lens aberration is interrelated and the zones respond uniquely to specific aberrations depending on their location within the figure. This is a unique and new method of detecting a variety of aberration types including coma, spherical, astigmatism, and three-point through the exposure of a photoresist material placed in the image plane of the system and the evaluation of these images.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: March 18, 2008
    Inventor: Bruce W. Smith
  • Publication number: 20070172745
    Abstract: A method for improved imaging performance of a microlithography photomask is described. By providing sub resolution evanescent wave assist features in regions surrounding a main photomask feature, the coupling of the evanescent energy from these features can add to the transmission efficiency of the main feature. The photomask comprises a transparent substrate support member having at least a first and second surface, wherein said first surface is smooth and said second surface is patterned with a plurality of grooves; a film coating disposed over said plurality of groves, wherein said film coating has one or more openings.
    Type: Application
    Filed: January 26, 2007
    Publication date: July 26, 2007
    Inventor: Bruce W. Smith
  • Patent number: 7233887
    Abstract: A method of level assist feature OPC layout is described using frequency model-based approach. Through low-pass spatial frequency filtering of a mask function, the local influence of zero diffraction energy can be determined. By determining isofocal intensity threshold requirements of an imaging process, a mask equalizing function can be designed. This provides the basis for frequency model-based assist feature layout. By choosing assist feature parameters that meet the requirements of the equalizing function, through-pitch focus and dose matching is possible for large two dimensional mask fields. The concepts introduced also lead to additional assist feature options and design flexibility.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: June 19, 2007
    Inventor: Bruce W. Smith
  • Patent number: 7170588
    Abstract: Reduction Talbot interference imaging is carried out using a glass or fused silica prism, where at least two surfaces within the prism allow for an increase in the propagating ray angles at the image plane compared to the object (the photomask) plane. Furthermore, by adding a second orthogonal pair of surfaces, X and Y order recombination is made possible thus allowing for the imaging in an orthogonal direction with a two-order interference scheme as well as repeating checkerboard (island and hole) patterns with a four-order interference scheme. A benefit of the invention is the reduced requirements of the photo mask, allowing for diffraction limited imaging with UV wavelengths in a media with index of unity (air) or larger (an immersion fluid). The prism interferometer is known as a Smith-Talbot prism lens.
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: January 30, 2007
    Inventor: Bruce W. Smith
  • Patent number: 7136143
    Abstract: Aberrations in an optical system can be detected and measured using a method comprised of a test target in the object plane of a projection system and imaging a photoresist film with the system. The test target comprises at least one open figure which comprises a multiple component array of phase zones, where the multiple zones are arranged within the open figure so that their response to lens aberration is interrelated and the zones respond uniquely to specific aberrations depending on their location within the figure. The method detects aberration types including coma, spherical, astigmatism, and three-point through the exposure of a photoresist material placed in the image plane of the system and the evaluation of these images.
    Type: Grant
    Filed: December 12, 2003
    Date of Patent: November 14, 2006
    Inventor: Bruce W. Smith
  • Patent number: 7092073
    Abstract: A microlithograpic tool, such as a projection stepper, for manufacturing integrated circuits, shapes light that illuminates a photomask with a chevron illumination system. The system uses either a chevron aperture mask of diffractive optical elements to shape a light source into four chevrons (110b, 120b, 130b, 140b). The chevrons are located in the corners of the circular pupil of the condenser lens. The chevrons may be a small a square poles at the corners or as large as an annular square ring. The chevrons provide superior performance for illuminating conventional X and Y oriented features of a photomask.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: August 15, 2006
    Assignee: ASML Netherlands B.V.
    Inventor: Bruce W. Smith
  • Patent number: 6934010
    Abstract: A photolithography mask for optically transferring a pattern formed in the mask onto a substrate and for negating optical proximity effects. The mask includes a plurality of resolvable features to be printed on the substrate, and at least one non-resolvable optical proximity correction feature disposed between two of the resolvable features to be printed, where the non-resolvable optical proximity correction feature has a transmission coefficient in the range of greater than 0% to less than 100%.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: August 23, 2005
    Assignee: ASML Masktools B.V.
    Inventor: Bruce W. Smith
  • Patent number: 6881523
    Abstract: A photolithography mask for optically transferring a pattern formed in said mask onto a substrate and for negating optical proximity effects. The mask includes a plurality of resolvable features to be printed on the substrate, where each of the plurality of resolvable features has a longitudinal axis extending in a first direction; and a pair of non-resolvable optical proximity correction features disposed between two of the plurality of resolvable features, where the pair of non-resolvable optical proximity correction features has a longitudinal axis extending in a second direction, wherein the first direction of the longitudinal axis of the plurality of resolvable features is orthogonal to the second direction of the longitudinal axis of the pair of non-resolvable optical proximity correction features.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: April 19, 2005
    Assignee: ASML Masktools B.V.
    Inventor: Bruce W. Smith
  • Patent number: 6846595
    Abstract: Photomask manufacture is improved by adding assist bars 320, 340 for isolated features 300. The bars 320, 340 are added at a center to center spacing that corresponds to the center to center spacing for densely packed features. By matching the assist bars to the densely packed features, the combined diffraction pattern of the isolated features is modified to more closely resemble the diffraction pattern of the densely packed features.
    Type: Grant
    Filed: February 14, 2001
    Date of Patent: January 25, 2005
    Assignee: ASML Netherlands B.V.
    Inventor: Bruce W. Smith
  • Patent number: 6835505
    Abstract: An attenuated phase shift mask for use in a lithography process includes a masking film made of at least one material with at least a silicon component which provides a transmission above about 0.5 percent and a phase shift of about a 180° for radiation at a wavelength at or below about 160 nm.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: December 28, 2004
    Assignee: Rochester Institute of Technology
    Inventor: Bruce W. Smith
  • Patent number: 6791667
    Abstract: A masking aperture for a photomask illumination system provides controlled on-axis and off-axis illumination. The masking aperture has a dithered pattern of pixels. The intensity of the pattern controls the illumination of the photomask. The masking aperture pattern defines one or more zones of illumination. Zones comprise elements that are patterned in accordance with a selected wavelength of incident light to diffract the incident light into an illumination pattern for illuminating a photomask. Each of the elements is constructed with a matrix of pixels. In the preferred embodiment the array of pixels is 8×8. The number of elements is generally greater than 3×3.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: September 14, 2004
    Assignee: ASML Netherlands B.V.
    Inventor: Bruce W. Smith
  • Publication number: 20040174506
    Abstract: Aberrations in an optical system can be detected and measured using a method comprised of a test target in the object plane of a projection system and imaging a photoresist film with the system. The test target comprises at least one open figure which comprises a multiple component array of phase zones, where the multiple zones are arranged within the open figure so that their response to lens aberration is interrelated and the zones respond uniquely to specific aberrations depending on their location within the figure. This is a unique and new method of detecting a variety of aberration types including coma, spherical, astigmatism, and three-point through the exposure of a photoresist material placed in the image plane of the system and the evaluation of these images.
    Type: Application
    Filed: December 12, 2003
    Publication date: September 9, 2004
    Inventor: Bruce W. Smith
  • Patent number: 6788388
    Abstract: A masking aperture for a photomask illumination system provides controlled on-axis and off-axis illumination. The masking aperture has a dithered pattern of pixels. The intensity of the pattern controls the illumination of the photomask. The masking aperture pattern defines one or more zones of illumination. Zones comprise elements that are patterned in accordance with a selected wavelength of incident light to diffract the incident light into an illumination pattern for illuminating a photomask. Each of the elements is constructed with a matrix of pixels. In the preferred embodiment the array of pixels is 8×8. The number of elements is generally greater than 3×3.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: September 7, 2004
    Assignee: ASML Netherlands B.V.
    Inventor: Bruce W. Smith
  • Publication number: 20040048167
    Abstract: A microlithograpic tool, such as a projection stepper, for manufacturing integrated circuits, shapes light that illuminates a photomask with a chevron illumination system. The system uses either a chevron aperture mask of diffractive optical elements to shape a light source into four chevrons (110b, 120b, 130b, 140b). The chevrons are located in the corners of the circular pupil of the condenser lens. The chevrons may be a small a square poles at the corners or as large as an annular square ring. The chevrons provide superior performance for illuminating conventional X and Y oriented features of a photomask.
    Type: Application
    Filed: August 4, 2003
    Publication date: March 11, 2004
    Inventor: Bruce W. Smith
  • Publication number: 20030112421
    Abstract: An image enhancement apparatus and method are disclosed. The apparatus consists of a spatial frequency filter where zero order mask diffraction information is reduced in an alternative pupil plane of the objective lens, specifically just beyond the mask plane. By introducing an angular specific transmission filter into this Fraunhofer diffraction field of the mask, user accessibility is introduced, allowing for a practical approach to frequency filtering. This frequency filtering is accomplished using a specifically designed interference filter coated over a transparent substrate. Alternatively, filtering can also be accomplished in a complimentary region near the wafer image plane or in both near-mask and near-wafer planes.
    Type: Application
    Filed: October 2, 2002
    Publication date: June 19, 2003
    Applicant: ASML NETHERLANDS B.V.
    Inventor: Bruce W. Smith
  • Patent number: 6556361
    Abstract: A imaging tool for use with a mask with features oriented along at least an x-axis or a y-axis where the x-axis extends in directions substantially perpendicular to the directions of the y-axis. The tool has a condenser lens with a condenser plate which is located in a condenser lens pupil plane and which has a condenser aperture with four-sides. The sides of the condenser aperture are oriented in substantially the same direction as either the x-axis or the y-axis. The condenser lens is positioned to place at least a portion of any illumination on at least a portion of the mask.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: April 29, 2003
    Assignee: Rochester Institute of Technology
    Inventors: Bruce W. Smith, John S. Petersen
  • Patent number: RE39349
    Abstract: A mask for use on a layer of imaging material which is located on at least a portion of one surface of a substrate in a lithography process in accordance with one embodiment of the present invention includes a layer of a masking material which has an optical density of at least 4.0 for wavelengths at or below about 180 nm and a thickness of less than about 1000 angstroms. Materials, such as tungsten and amorphous silicon, can be used for the mask.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: October 17, 2006
    Assignee: Rochester Institute of Technology
    Inventor: Bruce W. Smith
  • Patent number: RE40239
    Abstract: An illumination system for a microlithographic stepper has a light source that emits light of selected wavelength(s) along an optical path toward a photomask. An aperture mask is positioned in the path of the illumination light and between the light source and the photomask. The aperture mask has a dithered pattern of pixels. The intensity of the pattern controls the illumination of the photomask. The masking aperture pattern defines one or more zones of illumination. Each zone has elements that are patterned in accordance with a selected wavelength of incident light to diffract the incident light into an illumination pattern for illuminating a photomask. Each of the elements is constructed with a matrix of pixels. In the preferred embodiment the array of pixels is 8×8. The number of elements is generally greater than 3×3.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: April 15, 2008
    Assignee: ASML Netherlands B.V.
    Inventor: Bruce W. Smith