Patents by Inventor Shahid Butt
Shahid Butt 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: 7074525Abstract: Non-uniformity and image shortening are substantially reduced in an image printed on a substrate using a photolithographic mask in which the mask pattern includes at least one lines and spaces array adjacent to at least one clear region. At least one line feature is incorporated within the clear region of the mask pattern and is disposed in proximity to the lines and spaces array. The line feature has a line width that is smaller than a minimum resolution of the optical projection system. The image is printed by illuminating the photolithographic mask and projecting light transmitted through the photolithographic mask onto the substrate using the optical projection system.Type: GrantFiled: April 29, 2003Date of Patent: July 11, 2006Assignees: Infineon Technologies AG, International Business Machines CorporationInventors: Chung-Hsi J. Wu, Timothy Allan Brunner, Shahid Butt, Patrick Speno
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Patent number: 7056628Abstract: A mask is configured for projecting a structure pattern onto a semiconductor substrate in an exposure unit. The exposure unit has a minimum resolution limit for projecting the structure pattern onto the semiconductor substrate. The mask has a substrate, at least one raised first structure element on the substrate which has a lateral extent which is at least the minimum lateral extent that can be attained by the exposure unit, a configuration second raised structure elements which are arranged in an area surrounding the at least one first structure element on the substrate in the form of a matrix with a row spacing and a column spacing, whose shape and size are essentially identical to one another, and which have a respective lateral extent that is less than the minimum resolution limit of the exposure unit.Type: GrantFiled: September 2, 2003Date of Patent: June 6, 2006Assignee: Infineon Technologies AGInventors: Shahid Butt, Henning Haffner
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Patent number: 7016027Abstract: A method and system for detecting the quality of an alternating phase shift mask having a number of 180-degree phase shift areas alternating with a number of 0-degree phase shift areas is disclosed. In operation, a light source which provides wavelength-adjustable incident lights illuminates the incident lights on the alternating phase shift mask. The light outputs from boundaries between the 0-degree phase shift areas and the 180-degree phase shift areas of the alternating phase shift mask are detected. Relation curves of the wavelength of the incident light and a light intensity of the boundaries are then calculated. Phase errors of the alternating phase shift mask can thus be measured from the relation curves.Type: GrantFiled: May 8, 2003Date of Patent: March 21, 2006Assignee: Infineon Technologies AGInventors: Shahid Butt, Shoaib Zaidi
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Publication number: 20050255387Abstract: An active area pattern is formed atop a deep trench pattern with a single exposure using an alternative phase-shift mask. To prevent adjacent spaces of opposite phase from intersecting one another at the ends of substantially opaque features of the active area pattern, one or more connectors are used to connect the ends of the substantially opaque patterns. Trench regions of the deep trench pattern are arranged such that the conduction path of the connectors are interrupted and prevent the lines from shorting to one another. Alternatively, a bit line pattern or a word line pattern having a lines and spaces array and a support region are printed with a single exposure using an alternating phase-shift mask. At one end of the array region, lines having a respective phase shift extend into the support region, and lines of the opposite phase shift are terminated.Type: ApplicationFiled: May 14, 2004Publication date: November 17, 2005Applicants: Infineon Technologies North America Corp., International Business Machines CorporationInventors: Shahid Butt, Scott Bukofsky, Ramachandra Divakaruni, Carl Radens, Wayne Ellis
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Patent number: 6940583Abstract: A method of projecting a pattern from a mask onto a substrate comprises providing an energy source, a substrate, and a mask containing a pattern of features to be projected onto the substrate, and projecting an energy beam from the energy source though the mask toward the substrate to create a projected mask pattern image. The projected mask pattern image is created by zeroth and higher orders of the energy beam. The method then includes diffracting zeroth order beams of the projected mask pattern image to an extent that prevents the zeroth order beams from reaching the substrate, while permitting higher order beams of the projected mask pattern image to reach the substrate. Preferably, the zeroth order beams of the projected mask pattern image are diffracted at an obtuse angle.Type: GrantFiled: July 28, 2003Date of Patent: September 6, 2005Assignees: International Business Machines Corporation, Infineon Technologies North America Corp.Inventors: Shahid Butt, Martin Burkhardt
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Publication number: 20050168753Abstract: The properties of features formed in a substrate are measured. Interferometric illumination is used to illuminate regions of a substrate so that the features of interest occupy a greater proportion of the illuminated area. The signal-to-noise ratio of the measurement signal is therefore increased, and the sensitivity of the measurement is thus improved.Type: ApplicationFiled: February 3, 2004Publication date: August 4, 2005Applicant: Infineon Technologies North America Corp.Inventors: Shahid Butt, Syed Shoaib Zaidi
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Publication number: 20050024618Abstract: A method of projecting a pattern from a mask onto a substrate comprises providing an energy source, a substrate, and a mask containing a pattern of features to be projected onto the substrate, and projecting an energy beam from the energy source though the mask toward the substrate to create a projected mask pattern image. The projected mask pattern image is created by zeroth and higher orders of the energy beam. The method then includes diffracting zeroth order beams of the projected mask pattern image to an extent that prevents the zeroth order beams from reaching the substrate, while permitting higher order beams of the projected mask pattern image to reach the substrate. Preferably, the zeroth order beams of the projected mask pattern image are diffracted at an obtuse angle.Type: ApplicationFiled: July 28, 2003Publication date: February 3, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Shahid Butt, Martin Burkhardt
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Publication number: 20050009312Abstract: An electronic device including: a semiconductor substrate having an array of gate conductors, each having a length and a width, comprised of dummy gate conductors and functional gate conductors extending in a widthwise direction, the gate conductors positioned substantially parallel to each other in the widthwise direction and periodically spaced apart a fixed distance in a direction substantially perpendicular to the widthwise direction.Type: ApplicationFiled: June 26, 2003Publication date: January 13, 2005Applicants: INTERNATIONAL BUSINESS MACHINES CORPORATION, INFINEON NORTH AMERICA CORPInventors: Shahid Butt, Wayne Ellis, John Gabric
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Patent number: 6842222Abstract: A projected image is formed during a material substrate. A photolithographic mask is illuminated with substantially coherent light at an oblique angle of incidence with respect to a surface of the photolithographic mask. The photolithographic mask includes a substantially transparent mask substrate and one or more lines and spaces patterns formed on the mask substrate and having a periodicity P. The mask substrate includes at least one phase shifting region. At least part of the light that is transmitted through the photolithographic mask is collected using one or more projection lenses which project the portion of the transmitted light onto the material substrate. The material substrate is disposed substantially parallel with, but at a distance from, a focal plane of the projection lens system.Type: GrantFiled: April 4, 2003Date of Patent: January 11, 2005Assignee: Infineon Technologies AGInventors: Gerhard Kunkel, Shahid Butt, Alan Thomas, Juergen Preuninger
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Publication number: 20040229134Abstract: The relative surface area sizes of portions having distinct phase-shift and transmission of light of a pattern on a phase-shift mask substantially obey the condition that the product of surface area and transmission of the electrical field strength is the same for all of the portions. Then, frequency doubling occurs due to vanishing zero order diffraction orders and in the case of high-transition attenuated phase-shift masks a large first order diffraction amplitude reveals an even an improved as compared with conventional phase-shift masks. Two-dimensional matrix-like structures particularly on attenuated or halftone phase-shift masks can be arranged to image high-density patterns on a semiconductor wafer. The duty cycles of pattern matrices can be chosen being different from one in two orthogonal directions nevertheless leading to frequency doubling.Type: ApplicationFiled: February 27, 2004Publication date: November 18, 2004Inventors: Shahid Butt, Gerhard Kunkel
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Publication number: 20040223145Abstract: A method and system for detecting the quality of an alternating phase shift mask having a number of 180-degree phase shift areas alternating with a number of 0-degree phase shift areas is disclosed. In operation, a light source which provides wavelength-adjustable incident lights illuminates the incident lights on the alternating phase shift mask. The light outputs from boundaries between the 0-degree phase shift areas and the 180-degree phase shift areas of the alternating phase shift mask are detected. Relation curves of the wavelength of the incident light and a light intensity of the boundaries are then calculated. Phase errors of the alternating phase shift mask can thus be measured from the relation curves.Type: ApplicationFiled: May 8, 2003Publication date: November 11, 2004Inventors: Shahid Butt, Shoaib Zaidi
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Publication number: 20040219435Abstract: Non-uniformity and image shortening are substantially reduced in an image printed on a substrate using a photolithographic mask in which the mask pattern includes at least one lines and spaces array adjacent to at least one clear region. At least one line feature is incorporated within the clear region of the mask pattern and is disposed in proximity to the lines and spaces array. The line feature has a line width that is smaller than a minimum resolution of the optical projection system. The image is printed by illuminating the photolithographic mask and projecting light transmitted through the photolithographic mask onto the substrate using the optical projection system.Type: ApplicationFiled: April 29, 2003Publication date: November 4, 2004Applicants: Infineon Technologies North America Corp., International Business Machines CorporationInventors: Chung-Hsi J. Wu, Timothy Allan Brunner, Shahid Butt, Patrick Speno
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Publication number: 20040196445Abstract: A projected image is formed during a material substrate. A photolithographic mask is illuminated with substantially coherent light at an oblique angle of incidence with respect to a surface of the photolithographic mask. The photolithographic mask includes a substantially transparent mask substrate and one or more lines and spaces patterns formed on the mask substrate and having a periodicity P. The mask substrate includes at least one phase shifting region. At least part of the light that is transmitted through the photolithographic mask is collected using one or more projection lenses which project the portion of the transmitted light onto the material substrate. The material substrate is disposed substantially parallel with, but at a distance from, a focal plane of the projection lens system.Type: ApplicationFiled: April 4, 2003Publication date: October 7, 2004Inventors: Gerhard Kunkel, Shahid Butt, Alan Thomas, Juergen Preuninger
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Publication number: 20040131950Abstract: A mask is configured for projecting a structure pattern onto a semiconductor substrate in an exposure unit. The exposure unit has a minimum resolution limit for projecting the structure pattern onto the semiconductor substrate. The mask has a substrate, at least one raised first structure element on the substrate which has a lateral extent which is at least the minimum lateral extent that can be attained by the exposure unit, a configuration second raised structure elements which are arranged in an area surrounding the at least one first structure element on the substrate in the form of a matrix with a row spacing and a column spacing, whose shape and size are essentially identical to one another, and which have a respective lateral extent that is less than the minimum resolution limit of the exposure unit.Type: ApplicationFiled: September 2, 2003Publication date: July 8, 2004Inventors: Shahid Butt, Henning Haffner
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Patent number: 6670646Abstract: A mask (118) and method for patterning a semiconductor wafer. The mask (118) includes apertures (122) and assist lines (124) disposed between apertures (122). The assist lines (124) reduce the diffraction effects of the lithographic process, resulting in improved depth of focus and resolution of patterns on a semiconductor wafer.Type: GrantFiled: February 11, 2002Date of Patent: December 30, 2003Assignee: Infineon Technologies AGInventors: Zhijian Lu, Shahid Butt, Alois Gutmann
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Publication number: 20030153126Abstract: A mask (118) and method for patterning a semiconductor wafer. The mask (118) includes apertures (122) and assist lines (124) disposed between apertures (122). The assist lines (124) reduce the diffraction effects of the lithographic process, resulting in improved depth of focus and resolution of patterns on a semiconductor wafer.Type: ApplicationFiled: February 11, 2002Publication date: August 14, 2003Applicant: Infineon Technologies North America Corp.Inventors: Zhijian Lu, Shahid Butt, Alois Gutmann
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Patent number: 6606151Abstract: Methods and reticles for evaluating lenses are disclosed. In one instance, a reticle which permits light to pass therethrough is provided which includes a first surface with a grating profile formed thereon. The grating profile includes a plurality of grouped stepped portions. Each group of the stepped portions includes a first step which prevents light from propagating therethrough, a second step which propagates light therethrough and a third step which propagates light therethrough at an angle 60 degrees out of phase with the light propagated through the second step.Type: GrantFiled: July 27, 2001Date of Patent: August 12, 2003Assignees: Infineon Technologies AG, International Business Machines CorporationInventors: Gerhard Kunkel, Shahid Butt, Joseph Kirk
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Patent number: 6590657Abstract: A semiconductor body having an alignment mark comprising a material adapted to absorb impinging light and to radiate light in response to the absorption of the impinging light, such radiated light being radiated with a wavelength different from the wavelength of the impinging light. Also a method and apparatus for detecting an alignment mark on a semiconductor body. The method and apparatus successively scan an alignment illumination comprising the impinging light over the surface of the semiconductor surface and over the alignment mark. The impinging energy is reflected by the surface of the semiconductor when such impinging light is over and is reflected by the surface of the semiconductor. The impinging energy is absorbed by the material and is then radiated by the material when such impinging energy is scanned over such material. The reflected light is selectively filtered while the radiated light is passed to a detector.Type: GrantFiled: September 29, 1999Date of Patent: July 8, 2003Assignee: Infineon Technologies North America Corp.Inventors: Christian Summerer, Shahid Butt, Gerhard Kunkel, Uwe Paul Schroeder
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Patent number: 6571383Abstract: A method of fabricating a semiconductor device is outlined in FIG. 3. An ideal (or desired) pattern of a layer of the semiconductor device is designed (305). A first pass corrected pattern is then derived by correcting the ideal patterns for major effects, e.g., aerial image effects (315, 320). A second pass corrected pattern is then derived by correcting the first pass corrected patterns for remaining errors (304). The second pass corrected pattern can be used to build a photomask (345). The photomask can then be used to produce a semiconductor device, such a memory chip or logic chip (350).Type: GrantFiled: April 28, 2000Date of Patent: May 27, 2003Assignee: Infineon Technologies, AGInventors: Shahid Butt, Henning Haffner, Beate Frankowsky
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Patent number: 6566219Abstract: A method of forming a trench can be used in the fabrication of dynamic random access memory (DRAM) cells. In one aspect, a first layer of a first material (e.g., polysilicon) is formed over a semiconductor region (e.g., a silicon substrate). The first layer is patterned to remove portions of the first material. A second material (e.g., oxide) can then be deposited to fill the portions where the first material was removed. After removing the remaining portions of the first layer of first material, a trench can be etched in the semiconductor region. The trench would be substantially aligned to the second material.Type: GrantFiled: September 21, 2001Date of Patent: May 20, 2003Assignee: Infineon Technologies AGInventors: Gerhard Kunkel, Shahid Butt, Ramachandra Divakaruni, Armin M. Reith, Munir D. Naeem