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).
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Patent number: 8852850Abstract: 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: GrantFiled: February 3, 2005Date of Patent: October 7, 2014Assignee: Rochester Institute of TechnologyInventor: Bruce W. Smith
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Patent number: 7768648Abstract: 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: GrantFiled: November 14, 2006Date of Patent: August 3, 2010Inventor: Bruce W. Smith
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Patent number: 7345735Abstract: 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: GrantFiled: September 27, 2006Date of Patent: March 18, 2008Inventor: Bruce W. Smith
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Publication number: 20070172745Abstract: 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: ApplicationFiled: January 26, 2007Publication date: July 26, 2007Inventor: Bruce W. Smith
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Patent number: 7233887Abstract: 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: GrantFiled: January 21, 2003Date of Patent: June 19, 2007Inventor: Bruce W. Smith
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Patent number: 7170588Abstract: 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: GrantFiled: July 23, 2004Date of Patent: January 30, 2007Inventor: Bruce W. Smith
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Patent number: 7136143Abstract: 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: GrantFiled: December 12, 2003Date of Patent: November 14, 2006Inventor: Bruce W. Smith
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Patent number: 7092073Abstract: 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: GrantFiled: July 6, 2001Date of Patent: August 15, 2006Assignee: ASML Netherlands B.V.Inventor: Bruce W. Smith
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Patent number: 6934010Abstract: 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: GrantFiled: February 27, 2002Date of Patent: August 23, 2005Assignee: ASML Masktools B.V.Inventor: Bruce W. Smith
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Patent number: 6881523Abstract: 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: GrantFiled: March 13, 2002Date of Patent: April 19, 2005Assignee: ASML Masktools B.V.Inventor: Bruce W. Smith
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Patent number: 6846595Abstract: 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: GrantFiled: February 14, 2001Date of Patent: January 25, 2005Assignee: ASML Netherlands B.V.Inventor: Bruce W. Smith
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Patent number: 6835505Abstract: 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: GrantFiled: May 24, 2002Date of Patent: December 28, 2004Assignee: Rochester Institute of TechnologyInventor: Bruce W. Smith
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Patent number: 6791667Abstract: 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: GrantFiled: March 8, 2002Date of Patent: September 14, 2004Assignee: ASML Netherlands B.V.Inventor: Bruce W. Smith
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Publication number: 20040174506Abstract: 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: ApplicationFiled: December 12, 2003Publication date: September 9, 2004Inventor: Bruce W. Smith
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Patent number: 6788388Abstract: 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: GrantFiled: March 8, 2002Date of Patent: September 7, 2004Assignee: ASML Netherlands B.V.Inventor: Bruce W. Smith
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Publication number: 20040048167Abstract: 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: ApplicationFiled: August 4, 2003Publication date: March 11, 2004Inventor: Bruce W. Smith
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Publication number: 20030112421Abstract: 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: ApplicationFiled: October 2, 2002Publication date: June 19, 2003Applicant: ASML NETHERLANDS B.V.Inventor: Bruce W. Smith
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Patent number: 6556361Abstract: 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: GrantFiled: March 17, 2000Date of Patent: April 29, 2003Assignee: Rochester Institute of TechnologyInventors: Bruce W. Smith, John S. Petersen
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Patent number: RE39349Abstract: 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: GrantFiled: November 4, 2003Date of Patent: October 17, 2006Assignee: Rochester Institute of TechnologyInventor: Bruce W. Smith
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Patent number: RE40239Abstract: 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: GrantFiled: October 14, 2004Date of Patent: April 15, 2008Assignee: ASML Netherlands B.V.Inventor: Bruce W. Smith