Patents by Inventor Kwok F. Lai

Kwok F. Lai 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: 7585399
    Abstract: In one embodiment, a magnetron sputtering apparatus includes one or more magnet arrays for moving ions or charged particles on at least two plasma discharge paths on a target. Charged particles on one of the plasma discharge paths are moved in one direction, while charged particles on the other plasma discharge path are moved in the opposite direction to reduce rotational shifting of deposition flux on the patterned substrates. The plasma discharge paths may be formed by two symmetric magnet arrays or a single asymmetric magnet array rotated from behind the target.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: September 8, 2009
    Assignee: Novellus Systems, Inc.
    Inventors: Kwok F. Lai, Houchin Tang, legal representative, Kang Song, Douglas B. Hayden
  • Patent number: 6683425
    Abstract: In one embodiment, a magnetron apparatus includes an essentially flat target having a low height-to-width ratio. The essentially flat target may be planar, dish-shaped, or stepped-shape, for example. A main magnet is located behind the flat target to provide main magnetic fields. Magnets located near the target and underneath a substrate may be configured to maintain a high density plasma and to control the flow of plasma onto the substrate.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: January 27, 2004
    Assignee: Novellus Systems, Inc.
    Inventor: Kwok F. Lai
  • Patent number: 6497796
    Abstract: A magnetron source comprises a hollow cathode with a non-planar target. By using a magnet between the cathode and a substrate, plasma can be controlled to achieve high ionization levels, good step coverage, and good process uniformity. Step coverage uniformity is also improved by controlling the magnetic fields, and thus the flow of ions and electrons, near the plane of the substrate.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: December 24, 2002
    Assignee: Novellus Systems, Inc.
    Inventors: Kaihan A. Ashtiani, Karl B. Levy, Kwok F. Lai, Andrew L. Nordquist, Larry D. Hartsough
  • Patent number: 6444105
    Abstract: A novel hollow cathode magnetron source is disclosed. The source comprises a hollow cathode with a non-planar target. By using a magnet between the cathode and a substrate, plasma can be controlled to achieve high ionization levels, good step coverage, and good process uniformity.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: September 3, 2002
    Assignee: Novellus Systems, Inc.
    Inventors: Kwok F. Lai, Andrew L. Nordquist, Kaihan A. Ashtiani, Larry D. Hartsough, Karl B. Levy
  • Patent number: 6179973
    Abstract: A novel hollow cathode magnetron source is disclosed. The source comprises a hollow cathode with a non-planar target. By using a magnet between the cathode and a substrate, plasma can be controlled to achieve high ionization levels, good step coverage, and good process uniformity.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: January 30, 2001
    Assignee: Novellus Systems, Inc.
    Inventors: Kwok F. Lai, Andrew L. Nordquist, Kaihan A. Ashtiani, Larry D. Hartsough, Karl B. Levy
  • Patent number: 5593551
    Abstract: A magnetron sputtering source which is capable of very low pressure operation is disclosed. The source comprises a dish-shaped sputter target behind which is mounted a primary magnet for confining a plasma discharge adjacent to the front surface of the sputter target. A bucking magnet, positioned adjacent to the perimeter of the sputter target and, preferably, at the same level as the target, is used to prevent the magnetic field created by the primary magnet from spreading out at near the edge of the sputter target. This enables the source to operate at very low pressure and reduces the impedance of the discharge.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: January 14, 1997
    Assignee: Varian Associates, Inc.
    Inventor: Kwok F. Lai
  • Patent number: 5482611
    Abstract: A sputter magnetron ion source for producing an intense plasma in a cathode container which ionizes a high and substantial percentage of the sputter cathode material and means for extracting the ions of the cathode material in a beam. The ion extraction means is implemented by a magnetic field cusp configuration with a null region adjacent to the open end of the cathode container. Ions so produced are able to be directed at right angles to a substrate being coated for efficient via filling.
    Type: Grant
    Filed: October 8, 1993
    Date of Patent: January 9, 1996
    Inventors: John C. Helmer, Kwok F. Lai, Robert L. Anderson