Patents Assigned to Tencor Instruments, Inc.
  • 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