Patents by Inventor Niroomand Ardavan

Niroomand Ardavan 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: 6815308
    Abstract: An alignment mark mask element protects an underlying alignment mark during subsequent processing of the fabrication substrate. The alignment mark mask element is formed concurrent with formation of a photomask from a dual-tone photoresist that exhibits a pattern reversal upon exposure to an energy level. A portion of the dual-tone photoresist above the alignment mark is exposed to an energy sufficient to reverse a positive tone resist to a negative tone, which remains above the alignment mark after developing. The remainder of the dual-tone photoresist is exposed through a reticle at a lesser energy level and patterned to define aperture locations of a photomask for formation of semiconductor device features. In addition, a photomask for use on a fabrication substrate and an intermediate semiconductor device are disclosed. Methods of forming a photomask and an intermediate semiconductor device structure are also disclosed.
    Type: Grant
    Filed: August 15, 2002
    Date of Patent: November 9, 2004
    Assignee: Micron Technology, Inc.
    Inventors: Richard D. Holscher, Niroomand Ardavan
  • Publication number: 20040032031
    Abstract: An alignment mark mask element protects an underlying alignment mark during subsequent processing of the fabrication substrate. The alignment mark mask element is formed concurrent with formation of a photomask from a dual-tone photoresist that exhibits a pattern reversal upon exposure to an energy level. A portion of the dual-tone photoresist above the alignment mark is exposed to an energy sufficient to reverse a positive tone resist to a negative tone, which remains above the alignment mark after developing. The remainder of the dual-tone photoresist is exposed through a reticle at a lesser energy level and patterned to define aperture locations of a photomask for formation of semiconductor device features. In addition, a photomask for use on a fabrication substrate and an intermediate semiconductor device are disclosed. Methods of forming a photomask and an intermediate semiconductor device structure are also disclosed.
    Type: Application
    Filed: August 15, 2002
    Publication date: February 19, 2004
    Inventors: Richard D. Holscher, Niroomand Ardavan