Patents Represented by Attorney, Agent or Law Firm Peter Zowliski
  • Patent number: 6498640
    Abstract: A method for facilitating alignment measurements in a semiconductor fabrication process that uses a combination of underlying and latent images on a substrate to indicate alignment between a lithographic mask and the substrate. In an example embodiment of the method for measuring alignment, a substrate has a layer of photoresist disposed on it is illuminated through a reticle element resulting in the formation of a first plurality of underlying grating images. The first plurality of images has a repetitive and symmetrical pattern with equal spacing between images. A second plurality of latent grating images is formed in the photoresist having substantially the same pattern of images as the first plurality of images. The second plurality of images is disposed above from the first plurality of images, the first and second plurality of images serving as an indicator of alignment between the mask and the substrate when the combined images forming a repetitive pattern.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: December 24, 2002
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: David Ziger