Patents by Inventor Subramian S. Iyer

Subramian S. Iyer 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).

  • Method and apparatus for image adjustment
    Patent number: 6284443
    Abstract: A method of variably exposing photosensitive material. A semiconductor wafer is provided. A first target region and a second target region are identified on the semiconductor wafer. Photosensitive material is provided on the semiconductor wafer. An illuminating system including a source of illumination is provided. A mask is provided between the source of illumination and the photosensitive material. The photosensitive material is illuminated through the mask with the illuminating system to provide in a single step of the illuminating system a first illumination dose to the first target region and a second illumination dose to the second target region. The first illumination dose differs from the second illumination dose. No further illumination dose is provided to equalize the first illumination dose and the second illumination dose.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: September 4, 2001
    Assignee: International Business Machines Corporation
    Inventors: Brent A. Anderson, Michael S. Hibbs, Subramian S. Iyer