Patents by Inventor David F. Cheffings

David F. Cheffings 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: 6440825
    Abstract: A solid state fabrication technique for controlling the amount of outdiffusion from a three-dimensional film is comprised of the step of providing a first layer of insitu doped film in a manner to define an upper portion and a lower portion. A second layer of undoped film is provided on top of the first layer to similarly define an upper portion and a lower portion. The first and second layers are etched according to a predetermined pattern. The second layer is doped to obtain a desired dopant density which decreases from the upper portion to the lower portion. Outdiffusion of the dopant from the upper portion of the second layer results in the dopant migrating to the lower portion of the second layer. Thus, outdiffusion into the substrate, and the problems caused thereby, are eliminated or greatly reduced.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: August 27, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Fernando González, D. Mark Durcan, Luan C. Tran, Robert B. Kerr, David F. Cheffings, Howard E. Rhodes
  • Patent number: 6320235
    Abstract: The invention is a semiconductor memory structure having an electrically conductive substrate interconnect formed to provide electrical continuity between a buried contact region and a source/drain region of a transistor without overlap of the buried contact region with the source/drain region. The electrically conductive substrate interconnect is formed during an ion bombardment of the substrate wherein the ions enter the substrate at an oblique angle and underlie at least a portion of a region utilized to control the amount of ions entering the substrate.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: November 20, 2001
    Assignee: Micron Technology, Inc.
    Inventor: David F. Cheffings
  • Patent number: 6211545
    Abstract: A solid state fabrication technique for controlling the amount of outdiffusion from a three-dimensional film is comprised of the step of providing a first layer of insitu doped film in a manner to define an upper portion and a lower portion. A second layer of undoped film is provided on top of the first layer to similarly define an upper portion and a lower portion. The first and second layers are etched according to a predetermined pattern. The second layer is doped to obtain a desired dopant density which decreases from the upper portion to the lower portion. Outdiffusion of the dopant from the upper portion of the second layer results in the dopant migrating to the lower portion of the second layer. Thus, outdiffusion into the substrate, and the problems caused thereby, are eliminated or greatly reduced.
    Type: Grant
    Filed: May 12, 1999
    Date of Patent: April 3, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Fernando Gonzalez, D. Mark Durcan, Luan C. Tran, Robert B. Kerr, David F. Cheffings, Howard E. Rhodes
  • Patent number: 6159790
    Abstract: A solid state fabrication technique for controlling the amount of outdiffusion from a three-dimensional film is comprised of the step of providing a first layer of insitu doped film in a manner to define an upper portion and a lower portion. A second layer of undoped film is provided on top of the first layer to similarly define an upper portion and a lower portion. The first and second layers are etched according to a predetermined pattern. The second layer is doped to obtain a desired dopant density which decreases from the upper portion to the lower portion. Outdiffusion of the dopant from the upper portion of the second layer results in the dopant migrating to the lower portion of the second layer. Thus, outdiffusion into the substrate, and the problems caused thereby, are eliminated or greatly reduced.
    Type: Grant
    Filed: May 12, 1999
    Date of Patent: December 12, 2000
    Assignee: Micron Technology, Inc.
    Inventors: Fernando Gonzalez, D. Mark Durcan, Luan C. Tran, Robert B. Kerr, David F. Cheffings, Howard E. Rhodes
  • Patent number: 5994182
    Abstract: A solid state fabrication technique for controlling the amount of outdiffusion from a three-dimensional film is comprised of the step of providing a first layer of insitu doped film in a manner to define an upper portion and a lower portion. A second layer of undoped film is provided on top of the first layer to similarly define an upper portion and a lower portion. The first and second layers are etched according to a predetermined pattern. The second layer is doped to obtain a desired dopant density which decreases from the upper portion to the lower portion. Outdiffusion of the dopant from the upper portion of the second layer results in the dopant migrating to the lower portion of the second layer. Thus, outdiffusion into the substrate, and the problems caused thereby, are eliminated or greatly reduced.
    Type: Grant
    Filed: January 18, 1996
    Date of Patent: November 30, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Fernando Gonzalez, D. Mark Durcan, Luan C. Tran, Robert B. Kerr, David F. Cheffings, Howard E. Rhodes
  • Patent number: 5976960
    Abstract: The invention is a semiconductor memory structure having an electrically conductive substrate interconnect formed to provide electrical continuity between a buried contact region and a source/drain region of a transistor without overlap of the buried contact region with the source/drain region. The electrically conductive substrate interconnect is formed during an ion bombardment of the substrate wherein the ions enter the substrate at an oblique angle and underlie at least a portion of a region utilized to control the amount of ions entering the substrate.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: November 2, 1999
    Assignee: Micron Technology, Inc.
    Inventor: David F. Cheffings
  • Patent number: 5858845
    Abstract: The invention is a semiconductor memory structure having an electrically conductive substrate interconnect formed to provide electrical continuity between a buried contact region and a source/drain region of a transistor without overlap of the buried contact region with the source/drain region. The electrically conductive substrate interconnect is formed during an ion bombardment of the substrate wherein the ions enter the substrate at an oblique angle and underlie at least a portion of a region utilized to control the amount of ions entering the substrate.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: January 12, 1999
    Assignee: Micron Technology, Inc.
    Inventor: David F. Cheffings
  • Patent number: 5387550
    Abstract: A well in a semiconductor wafer is partially filled by a tungsten plug having an irregular surface. There is an aluminum line exterior of the well for electrically connecting the tungsten plug into an electrical circuit. A doped polysilicon fillet having an irregular surface meshing with the irregular surface of the tungsten plug fills the portion of the well between the plug and line, making a reproducible good electrical connection between the tungsten plug and the aluminum line. The poly fillet is formed by a poly deposit and planarization performed between a tungsten plug overetch and aluminum line deposition.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: February 7, 1995
    Assignee: Micron Technology, Inc.
    Inventors: David F. Cheffings, Martin C. Roberts
  • Patent number: 5378641
    Abstract: The invention is a semiconductor memory structure having an electrically conductive substrate interconnect formed to provide electrical continuity between a buried contact region and a source/drain region of a transistor without overlap of the buried contact region with the source/drain region. The electrically conductive substrate interconnect is formed during an ion bombardment of the substrate wherein the ions enter the substrate at an oblique angle and underlie at least a portion of a region utilized to control the amount of ions entering the substrate.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: January 3, 1995
    Assignee: Micron Semiconductor, Inc.
    Inventor: David F. Cheffings