Patents Assigned to J.A. Woollam Co. Inc.
  • Patent number: 5582646
    Abstract: A method of, and system for, applying light beam producing systems such as ellipsometers, polarimeters, polarized light reflectance and functionally similar systems, such that a beam of light produced thereby is caused to be incident upon a process element at an angle in excess of an associated Brewster angle while enabling the production of a signal sufficiently sensitive to changes in process element parameters, for use in "real-time" process element process monitoring and control, is disclosed. In addition a process element processing system and electron beam producing system and light beam producing system combination system is taught, wherein the electron beam producing and light beam producing systems are mounted to the process element processing system, (typically a (MBE) system), by input and output interface systems present at a location appropriate for conventional Reflection High Energy Electron Diffraction (RHEED) systems.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: December 10, 1996
    Assignee: J.A. Woollam Co. Inc.
    Inventors: John A. Woollam, Blaine D. Johs, Peter P. Chow
  • Patent number: 5521706
    Abstract: An ellipsometer system which includes a pivotal dispersive optics positioned to receive polychromatic light from an analyzer thereof, without further focusing after reflection from a substrate system, is presented. In addition, a rotating compensator, positioned between the analyzer and the dispersive optics, which serves to reduce detector element polarization dependent sensitivity to light entering thereto after it interacts with the dispersive optics, is disclosed. The method of the present invention can include application of mathematical correction factors to, for instance, substrate system characterizing PSI and DELTA values, or Fourier ALPHA and BETA coefficients.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: May 28, 1996
    Assignee: J. A. Woollam Co. Inc.
    Inventors: Steven E. Green, Shakil A. Pittal, Blaine D. Johs, John A. Woollam, David W. Doerr, Reed A. Christenson
  • Patent number: 5504582
    Abstract: An ellipsometer system which includes a pivotal dispersive optics positioned to receive polychromatic light from an analyzer thereof, without further focusing after reflection from a substrate system, is presented. In addition, a stationary compensator, positioned between an analyzer and the dispersive optics, which serves to reduce detector element polarization dependent sensitivity to light entering thereto after it interacts with the dispersive optics, is disclosed. The use of a light fiber to carry light from a source thereof, to a polarization state generator, is also disclosed. The method of the present invention can include application of mathematical correction factors to, for instance, substrate system characterizing PSI and DELTA values, or Fourier ALPHA and BETA coefficients.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: April 2, 1996
    Assignee: J. A. Woollam Co. Inc.
    Inventors: Blaine D. Johs, Shakil A. Pittal, Steven E. Green, John A. Woollam, David W. Doerr, Reed A. Christenson