Patents by Inventor Vance E. Hoffman, Jr.

Vance E. Hoffman, Jr. 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: 6521106
    Abstract: Sputtering apparatus using a collimating filter to limit the angles at which sputtered particles will reach the surface of the substrate or workpiece being processed is shown. The sputtering apparatus relies on a combination of a planar sputter source larger in size than the workpiece and having highly uniform emission characteristics across the much of its surface, including its center; a collimating filter; and low operating pressure to avoid scattering of sputtered atoms after they have passed through the collimation filter. In the preferred embodiment, the collimation filter is made from a material which has substantially the same thermal coefficient of expansion as the film which is deposited on the substrate. In one specific embodiment, a titanium collimation filter is used when the sputtering system is used to deposit films of titanium, titanium nitride or titanium/tungsten alloy.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: February 18, 2003
    Assignee: Novellus Systems, Inc.
    Inventors: Geri M. Actor, Ronald R. Cochran, Vance E. Hoffman, Jr.
  • Patent number: 5478455
    Abstract: A method for automatically controlling a collimated sputtering source that is controllable by a computer to compensate for the build-up of sputtered material on the collimator. The method involves providing software for the computer including a formula to calculate a multiplier as a function of the age of the collimator, sequentially depositing film on a series of substrates using the sputtering source, monitoring the age of the collimator, and using the software to periodically adjust the value of a controllable sputtering parameter as a function of the multiplier. The sputtering parameter is automatically adjusted by the software such that a property of the film deposited by the source on the series of substrates does not substantially vary among the substrates as sputtered material builds up on the collimator.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: December 26, 1995
    Assignee: Varian Associates, Inc.
    Inventors: Geri M. Actor, Stephen M. Higa, Vance E. Hoffman, Jr., Patrick O. Miller, Pamela R. Patterson
  • Patent number: 5252194
    Abstract: A magnetron sputter source providing a predetermined erosion distribution over the surface of a sputter target material is described. When the distribution is uniform, close coupling of the sputter target with the substrate to be coated is achieved, resulting in improved collection efficiency of the sputtered material by the wafer and improved film thickness uniformity. Elimination of erosion grooves provide for greater target consumption and longer target life. The cathode magnetron sputter source includes a rotating magnet assembly of a specific shape and a specific magnetic strength provides the desired erosion distribution. The target may be dished to improve uniformity near the periphery of the wafer.The resulting magnetron cathode is used for the deposition of thin films. Further applications of uniform magnetron erosion or preselected erosion include uniform or preselected magnetron sputter etch or reactive ion etch and concurrent deposition and etch.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: October 12, 1993
    Assignee: Varian Associates, Inc.
    Inventors: Richard E. Demaray, John C. Helmer, Robert L. Anderson, Young H. Park, Ronald R. Cochran, Vance E. Hoffman, Jr.