Patents Represented by Attorney Francis L. Masdelle
  • Patent number: 4662754
    Abstract: Described is a method for facilitating the alignment of a photomask with individual fields on the surfaces of a number of wafers onto which fields the pattern of the photomask is to be imaged for projection printing, each of said number of wafers carrying an identical array of fields produced in at least one previous printing process. For this purpose it is possible to choose one out of the identical batch of wafers, measure the rotational adjustment necessary to bring each field into the correct direction in the horizontal plane and to use the measured value for an automatic rotational adjustment of all other wafers of the batch.
    Type: Grant
    Filed: December 20, 1985
    Date of Patent: May 5, 1987
    Assignee: The Perkin-Elmer Corporation
    Inventor: Herbert E. Mayer