Patents by Inventor Young Mok Ham

Young Mok Ham 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).

  • Method for fabricating a phase shift mask
    Patent number: 5567552
    Abstract: A method for fabricating a phase shift mask is disclosed. In order to make the phase shift mask, an etching groove is formed on the light shielding portion of the quartz substrate and chrome is then formed on the center portion of the etching groove. The phase shift mask produces a phase shift effect without using phase shift materials, thereby increasing the optical contrast.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: October 22, 1996
    Assignee: Hyundai Electronics Industries
    Inventor: Young Mok Ham