Patents by Inventor Xianfeng Zhou

Xianfeng Zhou 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: 7354812
    Abstract: Multiple trench depths within an integrated circuit device are formed by first forming trenches in a substrate to a first depth, but of varying widths. Formation of a dielectric layer can cause some of the trenches to fill or close off while leaving other, wider trenches open. Removal of a portion of the dielectric material can then be tailored to expose a bottom of the open trenches while leaving remaining trenches filled. Removal of exposed portions of the underlying substrate can then be used to selectively deepen the open trenches, which can subsequently be filled. Such methods can be used to form trenches of varying depths without the need for subsequent masking.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: April 8, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Shubneesh Batra, Howard C. Kirsch, Gurtej S. Sandhu, Xianfeng Zhou, Chih-Chen Cho
  • Publication number: 20080042216
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: October 24, 2007
    Publication date: February 21, 2008
    Inventors: Mark Helm, Xianfeng Zhou
  • Patent number: 7304353
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Grant
    Filed: June 7, 2005
    Date of Patent: December 4, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20070224746
    Abstract: An integrated circuit and gate oxide forming process are disclosed which provide a gate structure that is simple to integrate with conventional fabrication processes while providing different gate oxide thicknesses for different transistors within the integrated circuit. For a flash memory, which may utilize the invention, the different gate oxide thicknesses may be used for lower voltage transistors, memory array transistors, and higher voltage transistors.
    Type: Application
    Filed: March 24, 2006
    Publication date: September 27, 2007
    Inventor: Xianfeng Zhou
  • Publication number: 20070218645
    Abstract: An oxide layer is formed over a substrate having a smaller isolation trench and a large isolation trench. A nitride layer is formed over the oxide layer such that it completely fills the smaller isolation trench and lines the larger isolation trench. The nitride layer is etched back to form a recess in the nitride layer in the smaller isolation trench while at least a portion of the nitride layer lining the larger isolation trench is completely removed. A layer of HDP oxide is deposited over the substrate, completely filling the smaller and larger isolation trenches. The HDP oxide layer is planarized to the upper surface of the substrate. The deeper larger isolation trench may be formed by performing an etching step after the nitride layer has been etched back, prior to depositing HDP oxide.
    Type: Application
    Filed: March 14, 2006
    Publication date: September 20, 2007
    Inventor: Xianfeng Zhou
  • Patent number: 7265012
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: September 4, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20070093017
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: December 4, 2006
    Publication date: April 26, 2007
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20070093016
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: December 4, 2006
    Publication date: April 26, 2007
    Inventors: Mark Helm, Xianfeng Zhou
  • Patent number: 7189607
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: March 13, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20070029635
    Abstract: The invention includes methods of forming oxide structures under corners of transistor gate stacks and adjacent trenched isolation regions. Such methods can include exposure of a semiconductor material to steam and H2, with the H2 being present to a concentration of from about 2% to about 40%, by volume. An oxide structure formed under the bottom corner of a transistor gate stack can have a bottom surface with a topography that includes a step of at least about 50 ?, and an upper surface directly over the bottom surface and having a topography that is substantially planar. Methodology of the present invention can be utilized to form semiconductor constructions suitable for incorporation into highly integrated circuitry. The highly integrated circuitry can be incorporated into electronic systems, and can, for example, be utilized in processors and/or memory storage devices.
    Type: Application
    Filed: August 5, 2005
    Publication date: February 8, 2007
    Inventors: Michael Smith, Sukesh Sandhu, Xianfeng Zhou, Graham Wolstenholme
  • Publication number: 20060046402
    Abstract: Methods of fabrication and flash memory structures eliminate process steps while increasing capacitive coupling between floating gates and control gates of the memory cells. A thick floating gate is deposited early in the process, and a height and width of the floating gate is controlled with deposition and etching or the use of spacers.
    Type: Application
    Filed: August 31, 2004
    Publication date: March 2, 2006
    Inventors: Di Li, Chun Chen, Graham Wolstenholme, Sukesh Sandhu, Xianfeng Zhou
  • Publication number: 20060043455
    Abstract: Multiple trench depths within an integrated circuit device are formed by first forming trenches in a substrate to a first depth, but of varying widths. Formation of a dielectric layer can cause some of the trenches to fill or close off while leaving other, wider trenches open. Removal of a portion of the dielectric material can then be tailored to expose a bottom of the open trenches while leaving remaining trenches filled. Removal of exposed portions of the underlying substrate can then be used to selectively deepen the open trenches, which can subsequently be filled. Such methods can be used to form trenches of varying depths without the need for subsequent masking.
    Type: Application
    Filed: September 1, 2004
    Publication date: March 2, 2006
    Inventors: Shubneesh Batra, Howard Kirsch, Gurtej Sandhu, Xianfeng Zhou, Chih-Chen Cho
  • Publication number: 20060043368
    Abstract: Methods of fabrication and flash memory structures eliminate process steps while increasing capacitive coupling between floating gates and control gates of the memory cells. A thick floating gate is deposited early in the process, and a height and width of the floating gate is controlled with deposition and etching or the use of spacers.
    Type: Application
    Filed: September 1, 2005
    Publication date: March 2, 2006
    Inventors: Di Li, Chun Chen, Graham Wolstenholme, Sukesh Sandhu, Xianfeng Zhou
  • Publication number: 20060003513
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: August 31, 2005
    Publication date: January 5, 2006
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20050227427
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: June 7, 2005
    Publication date: October 13, 2005
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20050026352
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: September 1, 2004
    Publication date: February 3, 2005
    Inventors: Mark Helm, Xianfeng Zhou
  • Patent number: 6849492
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Grant
    Filed: July 8, 2002
    Date of Patent: February 1, 2005
    Assignee: Micron Technology, Inc.
    Inventors: Mark Helm, Xianfeng Zhou
  • Publication number: 20040151489
    Abstract: The invention discloses an imaging system for producing double exposure composite images and application method therefor. This system includes a cartridge-clip camera and a cartridge-clip film. The cartridge-clip camera can achieve a conversion between a full-frame transmission and a half-frame transmission by a fixed-frame wheel, and can also provide a single-sheet-film card. The film may be a kind of information medium, on which there are various pre-exposed picture-and-word information latent images. When the cartridge-clip camera uses the cartridge-clip film, it can employ a positioning means for locating to make the cartridge clip provided with the film to be conveniently and accurately located in the cartridge-clip camera, and can produce accurately located double exposure composite images, thereby overcoming the drawback of known art, using conveniently and avoiding waste.
    Type: Application
    Filed: March 29, 2004
    Publication date: August 5, 2004
    Inventor: Xianfeng Zhou
  • Publication number: 20040005752
    Abstract: Wells are formed in a substrate where standard Vt and low Vt devices of both a first and second type are to be fabricated. Wells defining the locations of first type standard Vt devices are masked, and a first voltage threshold implant adjustment is performed within wells defining the second type standard Vt devices, and each of the first and second type low Vt devices. Wells that define the locations of second type standard Vt devices are masked, and a second voltage threshold implant adjustment is performed to the wells defining the first type standard Vt devices, and each of the first and second type low Vt devices. Doped polysilicon gate stacks are then formed over the wells. Performance characteristics and control of each device Vt is controlled by regulating at least one of the first and second voltage threshold implant adjustments, and the polysilicon gate stack doping.
    Type: Application
    Filed: July 8, 2002
    Publication date: January 8, 2004
    Inventors: Mark Helm, Xianfeng Zhou