Patents by Inventor Marilyn Hwan

Marilyn Hwan 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).

  • Patent number: 5863825
    Abstract: A method of providing etched alignment marks on a semiconductor workpiece that has a substantially planar surface, such as one that has been polished, for supporting accurate alignment of the workpiece in subsequent process operations. The surface of the semiconductor workpiece includes two layers of materials that abut at the workpiece surface. For example, the workpiece may include a layer of insulative material such as silicon dioxide forming several vias and a layer of conductive material such as tungsten forming plugs in the vias. The method includes etching the substantially planar surface to reduce a height of one of the materials below the height of the other material. For example, the tungstein plugs can be etched to a height that is below the height of the surrounding silicon dioxide. The location where the silicon dioxide abuts the tungsten produces a small bump. This bump then serves as an alignment mark for subsequent operations.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: January 26, 1999
    Assignee: LSI Logic Corporation
    Inventors: Nicholas F. Pasch, Marilyn Hwan, Richard Osugi, Colin Yates, Dawn Lee, Shumay Dou