Patents by Inventor David H. Wells

David H. Wells 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: 7368365
    Abstract: A method of forming a buried digit line is disclosed. Sacrificial spacers are formed along the sidewalls of an isolation trench, which is then filled with a sacrificial material. One spacer is masked while the other spacer is removed and an etch step into the substrate beneath the removed spacer forms an isolation window. Insulating liners are then formed along the sidewalls of the emptied trench, including into the isolation window. A digit line recess is then formed through the bottom of the trench between the insulating liners, which double as masks to self-align this etch. The digit line recess is then filled with metal and recessed back, with an optional prior insulating element deposited and recessed back in the bottom of the recess.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: May 6, 2008
    Inventor: David H. Wells
  • Publication number: 20080085587
    Abstract: Memory cell structures, including PSOIs, NANDs, NORs, FinFETs, etc., and methods of fabrication have been described that include a method of epitaxial silicon growth. The method includes providing a silicon layer on a substrate. A dielectric layer is provided on the silicon layer. A trench is formed in the dielectric layer to expose the silicon layer, the trench having trench walls in the <100> direction. The method includes epitaxially growing silicon between trench walls formed in the dielectric layer.
    Type: Application
    Filed: October 4, 2006
    Publication date: April 10, 2008
    Inventors: David H. Wells, Du Li
  • Publication number: 20080057692
    Abstract: Single spacer processes for multiplying pitch by a factor greater than two are provided. In one embodiment, n, where n?2, tiers of stacked mandrels are formed over a substrate, each of the n tiers comprising a plurality of mandrels substantially parallel to one another. Mandrels at tier n are over and parallel to mandrels at tier n?1, and the distance between adjoining mandrels at tier n is greater than the distance between adjoining mandrels at tier n?1. Spacers are simultaneously formed on sidewalls of the mandrels. Exposed portions of the mandrels are etched away and a pattern of lines defined by the spacers is transferred to the substrate.
    Type: Application
    Filed: August 30, 2006
    Publication date: March 6, 2008
    Inventors: David H. Wells, Mirzafer K. Abatchev
  • Publication number: 20080044979
    Abstract: Some embodiments include formation of at least one cavity in a first semiconductor material, followed by epitaxially growing a second semiconductor material over the first semiconductor material and bridging across the at least one cavity. The cavity may be left open, or material may be provided within the cavity. The material provided within the cavity may be suitable for forming, for example, one or more of electromagnetic radiation interaction components, transistor gates, insulative structures, and coolant structures. Some embodiments include one or more of transistor devices, electromagnetic radiation interaction components, transistor devices, coolant structures, insulative structures and gas reservoirs.
    Type: Application
    Filed: August 18, 2006
    Publication date: February 21, 2008
    Inventors: David H. Wells, Eric R. Blomiley
  • Publication number: 20070281493
    Abstract: A single crystal silicon etching method includes providing single crystal silicon substrate having at least one trench therein. The substrate is exposed to an anisotropic etchant which undercuts the silicon. By controlling the length of the etch, single crystal silicon islands or smooth vertical walls in the single crystal silicon may be created.
    Type: Application
    Filed: June 2, 2006
    Publication date: December 6, 2007
    Inventors: Janos Fucsko, David H. Wells, Patrick Flynn, Whonchee Lee
  • Publication number: 20070278183
    Abstract: A single crystal silicon etching method includes providing a single crystal silicon substrate having at least one trench therein. The substrate is exposed to a buffered fluoride etch solution which undercuts the silicon to provide lateral shelves when patterned in the <100> direction. The resulting structure includes an undercut feature when patterned in the <100> direction.
    Type: Application
    Filed: June 2, 2006
    Publication date: December 6, 2007
    Inventors: Whonchee Lee, Janos Fucsko, David H. Wells
  • Publication number: 20070281488
    Abstract: A method of forming at least one undercut structure in a semiconductor substrate. The method comprises providing a semiconductor substrate, forming at least one doped region in the semiconductor substrate, and removing the at least one doped region to form at least one undercut structure in the semiconductor substrate. The at least one undercut structure may include at least one substantially vertical shelf, at least one substantially horizontal shelf, and at least one faceted surface. The at least one doped region may be formed by implanting an impurity in the semiconductor substrate, which is, optionally, annealed. The at least one doped region may be removed selective to the undoped portion of the semiconductor substrate by at least one of wet etching or dry etching. An intermediate semiconductor structure that comprises a single crystalline silicon substrate and at least one undercut structure formed in the single crystalline silicon substrate is also disclosed.
    Type: Application
    Filed: June 2, 2006
    Publication date: December 6, 2007
    Inventors: David H. Wells, H. Montgomery Manning
  • Patent number: 7229895
    Abstract: A method of forming a buried digit line is disclosed. Sacrificial spacers are formed along the sidewalls of an isolation trench, which is then filled with a sacrificial material. One spacer is masked while the other spacer is removed and an etch step into the substrate beneath the removed spacer forms an isolation window. Insulating liners are then formed along the sidewalls of the emptied trench, including into the isolation window. A digit line recess is then formed through the bottom of the trench between the insulating liners, which double as masks to self-align this etch. The digit line recess is then filled with metal and recessed back, with an optional prior insulating element deposited and recessed back in the bottom of the recess.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: June 12, 2007
    Assignee: Micron Technology, Inc
    Inventor: David H. Wells
  • Patent number: 7161211
    Abstract: Aluminum-containing films having an oxygen content within the films. The aluminum-containing film is formed by introducing hydrogen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: January 9, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Kanwal K. Raina, David H. Wells
  • Patent number: 6893905
    Abstract: An aluminum-containing film having an oxygen content within the film. The aluminum-containing film is formed by introducing hydrogen gas and oxygen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: May 17, 2005
    Assignee: Micron Technology, Inc.
    Inventors: Kanwal K. Raina, David H. Wells
  • Publication number: 20030127744
    Abstract: Aluminum-containing films having an oxygen content within the films. The aluminum-containing film is formed by introducing hydrogen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
    Type: Application
    Filed: November 6, 2002
    Publication date: July 10, 2003
    Inventors: Kanwal K. Raina, David H. Wells
  • Patent number: 6555402
    Abstract: An extraction grid for field emitter tip structures and method of forming are described. A conductive layer is deposited over an insulative layer formed over the field emitter tip structures. The conductive layer is milled using ion milling. Owing to topographical differences along an exposed surface of the conductive layer, ions strike the exposed surface at various angles of incidence. As etch rate from ion milling is dependent at least in part upon angle of incidence, a selectivity based on varying topography of the exposed surface (“topographic selectivity”) results in non-uniform removal of material thereof. In particular, portions of the conductive layer in near proximity to the field emitter tip structures are removed faster than portions of the conductive layer between emitter tip structures. Thus, portions of the insulative layer in near proximity to the field emitter tip structures may be exposed while leaving intervening portions of the conductive layer for forming the extraction grid.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: April 29, 2003
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, Ji Ung Lee, Aaron R. Wilson
  • Patent number: 6534244
    Abstract: A phase-shifting lithographic mask, a method for its fabrication, and a method for its use in forming field-emission display emitters is described. The mask is made from a plate and has field and pattern regions that both transmit light of a given wavelength. The pattern region is a plurality of regularly spaced etched regions of the plate, with the optical path length of the pattern region differing from the optical path length of the field region by an odd integer multiple of one-half the light wavelength. Use of phase-shifting lithography improves depth-of-focus, and correspondingly relaxes planarity requirements. The pattern region of the mask is sized to expose a photoresist layer used in fabricating field-emission display emitters in just a single light exposure, thereby avoiding the disadvantages associated with conventional dual pass phase-shifting lithography.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: March 18, 2003
    Assignee: Micron Technology, Inc.
    Inventors: David A. Zimlich, David H. Wells
  • Publication number: 20020190387
    Abstract: An aluminum-containing film having an oxygen content within the film. The aluminum-containing film is formed by introducing hydrogen gas and oxygen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
    Type: Application
    Filed: June 26, 2002
    Publication date: December 19, 2002
    Inventors: Kanwal K. Raina, David H. Wells
  • Patent number: 6495296
    Abstract: A method, composition, and article for patterning and depositioning a substrate employing a colloidal suspension includes the step of agitating the colloidal suspension to eliminate aggregations of colloidal particles in the substrate. The colloidal suspension may include a plurality of colloidal particles in a suspension medium which may comprise deionized water, a resist such as photoresist, and a solvent.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: December 17, 2002
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, James J. Hofmann
  • Publication number: 20020185963
    Abstract: An arrangement of spacer posts in a flat panel display. The spacer posts maintain a fixed separation between a back plate and a face plate. The back plate includes one or more electron emission sources. Phosphors or other electro-optic material are distributed among a plurality of pixel areas on the face plate. The pixel areas are arranged in distinct groups, where each group contains N adjacent pixel areas. Each pixel area includes an area free of phosphor material. Within each group of N pixel areas, the respective phosphor-free areas of the N pixel areas are contiguous so as to form a combined phosphor-free area equal to or greater than the transverse cross-section of one end of a spacer. Consequently, a spacer can be attached to the face plate at each combined phosphor-free area without disrupting the uniformity of the distribution of phosphors on the face plate.
    Type: Application
    Filed: June 7, 2001
    Publication date: December 12, 2002
    Applicant: Pixtech S.A
    Inventors: Jimmy J. Browning, David H. Wells, Jianping Yang
  • Patent number: 6461774
    Abstract: A phase-shifting lithographic mask, a method for its fabrication, and a method for its use in forming field-emission display emitters is described. The mask is made from a plate and has field and pattern regions that both transmit light of a given wavelength. The pattern region is a plurality of regularly spaced etched regions of the plate, with the optical path length of the pattern region differing from the optical path length of the field region by an odd integer multiple of one-half the light wavelength. Use of phase-shifting lithography improves depth-of-focus, and correspondingly relaxes planarity requirements. The pattern region of the mask is sized to expose a photoresist layer used in fabricating field-emission display emitters in just a single light exposure, thereby avoiding the disadvantages associated with conventional dual pass phase-shifting lithography.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: October 8, 2002
    Assignee: Micron Technology, Inc.
    Inventors: David A. Zimlich, David H. Wells
  • Patent number: 6455939
    Abstract: An aluminum-containing film having an oxygen content within the film. The aluminum-containing film is formed by introducing hydrogen gas and oxygen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress.
    Type: Grant
    Filed: May 15, 2000
    Date of Patent: September 24, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Kanwal K. Raina, David H. Wells
  • Patent number: 6451513
    Abstract: A phase-shifting lithographic mask, a method for its fabrication, and a method for its use in forming field-emission display emitters is described. The mask is made from a plate and has field and pattern regions that both transmit light of a given wavelength. The pattern region is a plurality of regularly spaced etched regions of the plate, with the optical path length of the pattern region differing from the optical path length of the field region by an odd integer multiple of one-half the light wavelength. Use of phase-shifting lithography improves depth-of-focus, and correspondingly relaxes planarity requirements. The pattern region of the mask is sized to expose a photoresist layer used in fabricating field-emission display emitters in just a single light exposure, thereby avoiding the disadvantages associated with conventional dual pass phase-shifting lithography.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: September 17, 2002
    Assignee: Micron Technology, Inc.
    Inventors: David A. Zimlich, David H. Wells
  • Patent number: 6428943
    Abstract: A method, composition, and article for patterning and depositioning a substrate employing a colloidal suspension includes the step of agitating the colloidal suspension to eliminate aggregations of colloidal particles in the substrate. The colloidal suspension may include a plurality of colloidal particles in a suspension medium which may comprise deionized water, a resist such as photoresist, and a solvent.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: August 6, 2002
    Assignee: Micron Technology, Inc.
    Inventors: David H. Wells, James J. Hofmann