Patents by Inventor David E. Weldon

David E. Weldon 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: 5803799
    Abstract: A polishing head for polishing a semiconductor wafer includes a housing, a wafer carrier movably mounted to the housing, and a wafer retainer movably mounted to the housing. The wafer carrier forms a wafer supporting surface, and the wafer retainer is shaped to retain a wafer in place on the wafer-supporting surface. A first fluid actuator is coupled to the wafer carrier to bias the wafer carrier in a selected direction with respect to the housing, and a second fluid actuator is coupled to the wafer retainer to bias the wafer retainer in a second selected direction with respect to the housing. First and second fluid conduits are coupled to the first and second actuators, respectively, such that fluid pressures in the first and second actuators are separately and independently adjustable with respect to one another. Biasing forces on the retainer can thereby be dynamically adjusted with respect to biasing forces on the carrier during the polishing operation.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: September 8, 1998
    Assignee: OnTrak Systems, Inc.
    Inventors: Konstantin Volodarsky, David E. Weldon
  • Patent number: 5800248
    Abstract: A technique for controlling a polishing rate across a substrate surface when performing CMP, in order to obtain uniform polishing of the substrate surface. A support housing which underlies a polishing pad includes a plurality of openings for dispensing a pressurized fluid. The openings are arranged into a pre-configured pattern for dispensing the fluid to the underside of the pad opposite the substrate surface being polished. The openings are configured into a number of groupings, in which a separate channel is used for each grouping so that fluid pressure for each group of openings can be separately and independently controlled.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: September 1, 1998
    Assignee: Ontrak Systems Inc.
    Inventors: Anil K. Pant, Douglas W. Young, Anthony S. Meyer, Konstantin Volodarsky, David E. Weldon
  • Patent number: 5593344
    Abstract: A semi-conductor wafer polishing machine having a polishing pad assembly and a wafer holder includes a support positioned adjacent the polishing pad assembly. This support has at least one fluid inlet connectable to a source of fluid at a higher pressure, at least one fluid outlet connectable to a fluid drain at a lower pressure, and at least one bearing surface over which fluid flows from the source to the drain. The polishing pad is supported by the fluid over the bearing surface for low-friction movement with respect to the support. Similar fluid bearings can be used in the wafer holder. An array of generally parallel grooves is provided on a belt support surface to reduce hydroplaning of a polishing belt. A turbine drive system rotates a wafer chuck in a wafer holder.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: January 14, 1997
    Assignee: Ontrak Systems, Inc.
    Inventors: David E. Weldon, Boguslaw A. Nagorski, Homayoun Talieh
  • Patent number: 5575707
    Abstract: A polishing pad cluster for polishing a semiconductor wafer having multiple integrated circuit dies includes a pad support and multiple polishing pads. Each pad has a polishing area substantially smaller than the wafer but not substantially smaller than an individual one of the integrated circuit dies. Each polishing pad is mounted to a respective polishing pad mount, which is in turn supported by the support. Each mount includes a respective joint having at least two degrees of freedom to allow the associated polishing pad to articulate with respect to the support to conform to the wafer. Each mount is substantially rigid in a direction perpendicular to the pad toward the pad support, and in some cases the adjacent mounts are completely isolated from one another. A magnet is used to bias the polishing pad against the wafer.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: November 19, 1996
    Assignee: Ontrak Systems, Inc.
    Inventors: Homayoun Talieh, David E. Weldon
  • Patent number: 5571044
    Abstract: A semi-conductor wafer polishing machine having at least one polishing pad assembly and at least one wafer holder positioned to hold a semi-conductor wafer against the polishing pad assembly includes a joint having two axes of rotation intersecting at a center of rotation. A wafer chuck is supported on the joint adjacent the periphery of the chuck to provide higher material removal rates at the center of the wafer than the periphery of the wafer during polishing.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: November 5, 1996
    Assignee: Ontrak Systems, Inc.
    Inventors: Hooman Bolandi, David E. Weldon
  • Patent number: 5558568
    Abstract: A semi-conductor wafer polishing machine having a polishing pad assembly and a wafer holder includes a support positioned adjacent the polishing pad assembly. The support includes multiple fluid bearings that support the polishing pad assembly on the support. These fluid bearings are arranged concentrically to provide concentric regions of support for the polishing pad assembly, and each fluid bearing is coupled to a respective source of pressurized fluid at a respective pressure.
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: September 24, 1996
    Assignee: Ontrak Systems, Inc.
    Inventors: Homayoun Talieh, David E. Weldon, Boguslaw A. Nagorski
  • Patent number: 4482149
    Abstract: An arm exercising device is provided having an exercising arm adjustable to different lengths to accommodate forearms of different lengths and attached to a bearing-supported lateral rod which has an upright portion at the other end.Springs or other tension devices are attached at one end to the lateral rod and, at the other end, to a tension bar which is adjustable with respect to the base.In one variation, the tension arm can be re-positioned 180 degrees from its initial position, thereby permitting use of the device for exercising right or left arms. In a further refinement, safety stops are provided which limit the movement of the exercising arm, thereby preventing it from passing the upright position.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: November 13, 1984
    Inventor: David E. Weldon