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).

  • Publication number: 20030020901
    Abstract: 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: Application
    Filed: July 27, 2001
    Publication date: January 30, 2003
    Inventors: Gerhard Kunkel, Shahid Butt, Joseph Kirk
  • Patent number: 6421820
    Abstract: A semiconductor device can be fabricated using a photomask that has been modified using an assist feature design method (see e.g., FIG. 4A) based on normalized feature spacing. Before the device can be fabricated, a layout of original shapes is designed (402). For at least some of the original shapes, the width of the shape and a distance to at least one neighboring shape are measured (404). A modified shape can then be generated by moving edges of the original shape based on the width and distance measurements (406). This modification can be performed on some or all of the original shapes (408). For each of the modified shapes, a normalized space and correct number of assist features can be computed (410). The layout is then modified by adding the correct number of assist features in a space between the modified shape and the neighboring shape (412). This modified layout can then be used in producing a photomask, which can in turn be used to produce a semiconductor device.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: July 16, 2002
    Assignees: Infineon Technologies AG, Internation Business Machines Corporation
    Inventors: Scott M. Mansfield, Lars W. Liebmann, Shahid Butt, Henning Haffner
  • Publication number: 20020068400
    Abstract: 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: Application
    Filed: September 21, 2001
    Publication date: June 6, 2002
    Applicant: Infineon Technologies North America Corp.
    Inventors: Gerhard Kunkel, Shahid Butt, Ramachandra Divakaruni, Armin M. Reith, Munir D. Naeem
  • Patent number: 6316168
    Abstract: A method for etching a surface includes the steps of providing an under layer formed on the surface and a top layer formed on the under layer. The top layer is patterned to expose portions of the under layer, and a layer including silicon is formed on the exposed portions of the under layer. The top layer is removed to expose the under layer in portions other than the portions of the under layer having the silicon layer thereon, and the under layer is etched in portions other than the portions of the under layer having the silicon layer thereon to expose the surface.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: November 13, 2001
    Assignee: Siemens Aktiengesellschaft
    Inventors: Shahid Butt, Uwe Paul Schroeder
  • Patent number: 6282116
    Abstract: A dynamic random access memory is formed in a silicon chip in arrays of clusters, each of four cells in a single active area. Each active area is cross-shaped with vertical trenches at the four ends of the two crossbars. The central region of the active area where the two crossbars intersect serves as the common base region of the four transistors of the cluster. The top of the base region serves as a common drain for the four transistors and each transistor has a separate channel along the wall of its associated vertical trench that provides its storage capacitor. Each cluster includes a common bit line and four separate word-line contacts.
    Type: Grant
    Filed: June 26, 2000
    Date of Patent: August 28, 2001
    Assignees: Infineon Technologies North America Corp., International Business Machines Corporation
    Inventors: Gerhard Kunkel, Shahid Butt, Carl J Radens
  • Patent number: 6118683
    Abstract: A dynamic random access memory is formed in a silicon chip in arrays of clusters, each of four cells in a single active area. Each active area is cross-shaped with vertical trenches at the four ends of the two crossbars. The central region of the active area where the two crossbars intersect serves as the common base region of the four transistors of the cluster. The top of the base region serves as a common drain for the four transistors and each transistor has a separate channel along the wall of its associated vertical trench that provides its storage capacitor. Each cluster includes a common bit line and four separate word-line contacts.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: September 12, 2000
    Assignees: Infineon Technologies North America Corporation, International Business Machines Corporation
    Inventors: Gerhard Kunkel, Shahid Butt, Carl J. Radens
  • Patent number: 6114074
    Abstract: A pattern for a mask used in lithographic processing, in accordance with the invention, includes a plurality of elongated structures disposed substantially parallel to each other on a substrate and a plurality of sub-resolution extrusions extending transversely from the elongated structures into spaces between the elongated structures, the plurality of extrusions having a substantially same size in a direction parallel to the elongated structures, the plurality of extrusions being spaced apart periodically in the direction parallel to the elongated structures, the elongated structures and extrusions being formed from an energy absorbent material.
    Type: Grant
    Filed: March 11, 1999
    Date of Patent: September 5, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventors: Enio Luiz Carpi, Shahid Butt