Patents by Inventor Lawrence C. Lei

Lawrence C. Lei 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: 5213650
    Abstract: An apparatus is disclosed for removing one or more materials deposited on the backside and end edges of a semiconductor wafer which includes means for urging the front side of the wafer against a faceplate in a vacuum chamber; means for flowing one or more gases through a space maintained between the front side of the wafer and the faceplate; and means for forming a plasma in a gap maintained between the backside of the wafer and susceptor to remove materials deposited on the backside and end edge of the wafer; the gas flowing through the space between the front side of the wafer and the faceplate acting to prevent the plasma from removing materials on the front side of the wafer.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: May 25, 1993
    Assignee: Applied Materials, Inc.
    Inventors: David N. Wang, Lawrence C. Lei, Mei Chang, Cissy Leung
  • Patent number: 5075256
    Abstract: A method and apparatus are disclosed for removing one or more materials deposited on the backside and end edges of a semiconductor wafer which comprises urging the front side of the wafer against a faceplate in a vacuum chamber; flowing one or more gases through a space maintained between the front side of the wafer and the faceplate; and forming a plasma in a gap maintained between the backside of the wafer and susceptor to remove materials deposited on the backside and end edge of the wafer; the gas flowing through the space between the front side of the wafer and the faceplate acting to prevent the plasma from removing materials on the front side of the wafer.
    Type: Grant
    Filed: August 25, 1989
    Date of Patent: December 24, 1991
    Assignee: Applied Materials, Inc.
    Inventors: David N. Wang, Lawrence C. Lei, Mei Chang, Cissy Leung
  • Patent number: 4714536
    Abstract: A planar magnetron sputtering device has an extended flat circular target source in opposed spaced parallel relationship with a generally flat article to be coated, placed within an evacuated coating chamber. Crossed electric and magnetic fields in the chamber are established in order to set up a plasma adjacent the target. The magnetic field is provided by a magnetic assembly of permanent magnets on the non-vacuum side of the target. The magnetic assembly is smaller in diameter than the target, but is mounted to a means for moving the assembly laterally over the entire area of the target. This means for moving sweeps the magnetic assembly in an eccentric path generally centered on the target center, with the path being non-reentrant and precessing about the target center with time. In this manner, the path sweeps different areas on successive rotations about the center, and a given area of target is exposed to the magnetic field at many successively different orientations.
    Type: Grant
    Filed: March 31, 1987
    Date of Patent: December 22, 1987
    Assignee: Varian Associates, Inc.
    Inventors: Kenneth F. Freeman, Charles B. Garrett, David J. Harra, Lawrence C. Lei