Patents by Inventor Dov E. Hirsch

Dov E. Hirsch 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).

  • Laser apparatus and method for measuring stress in a thin film using multiple wavelengths
    Patent number: 5248889
    Abstract: An apparatus and a method for measuring the radius of curvature of a surface using a laser beam with a wavelength selectable from a plurality wavelengths are disclosed. The present invention avoids poor measurement due to destructive interference of the beams reflected at a thin film's upper and lower surfaces. The present invention is applicable to laser reflection stress measurement apparatuses of both scanning and beam-splitting types.
    Type: Grant
    Filed: February 13, 1991
    Date of Patent: September 28, 1993
    Assignee: Tencor Instruments, Inc.
    Inventors: Ilan A. Blech, Dov E. Hirsch
  • Laser apparatus and method for measuring stress in a thin film using multiple wavelengths
    Patent number: 5134303
    Abstract: In accordance with the present invention, an apparatus and a method for measuring the radius of curvature of a surface using laser beams of multiple wavelengths are provided. The present invention avoids poor measurement due to destructive interference of the beams reflected at a thin film's upper and lower surfaces. The present invention is applicable to laser reflection stress measurement apparatuses of both scanning and beam-splitting types.
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: July 28, 1992
    Assignee: Flexus, Inc.
    Inventors: Ilan A. Blech, Dov E. Hirsch