Patents by Inventor Kirk Prall

Kirk Prall 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: 7569468
    Abstract: Methods and apparatus are described to facilitate forming memory devices with low resistance polysilicon local interconnects that allow a smaller array feature size and therefore facilitate forming arrays of a denser array format. Embodiments of the present invention are formed utilizing a wet etch process that has a high selectivity, allowing the deposition and etching of polysilicon local interconnects to source regions of array transistors. By providing for a local interconnect of polysilicon, a smaller source region and/or drain region can also be utilized, further decreasing the required word line spacing. Low resistance polysilicon local source interconnects can also couple to an increased number of memory cells, thereby reducing the number of contacts made to an array ground.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: August 4, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Chun Chen, Guy Blalock, Graham Wolstenholme, Kirk Prall
  • Patent number: 7517749
    Abstract: Methods and apparatus are described to facilitate forming memory devices with low resistance polysilicon local interconnects that allow a smaller array feature size and therefore facilitate forming arrays of a denser array format. Embodiments of the present invention are formed utilizing a wet etch process that has a high selectivity, allowing the deposition and etching of polysilicon local interconnects to source regions of array transistors. By providing for a local interconnect of polysilicon, a smaller source region and/or drain region can also be utilized, further decreasing the required word line spacing. Low resistance polysilicon local source interconnects can also couple to an increased number of memory cells, thereby reducing the number of contacts made to an array ground.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: April 14, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Chun Chen, Guy Blalock, Graham Wolstenholme, Kirk Prall
  • Publication number: 20090072303
    Abstract: An array of memory cells configured to store at least one bit per one F2 includes substantially vertical structures providing an electronic memory function spaced apart a distance equal to one half of a minimum pitch of the array. The structures providing the electronic memory function are configured to store more than one bit per gate. The array also includes electrical contacts to the memory cells including the substantially vertical structures. The cells can be programmed to have one of a number of charge levels trapped in the gate insulator adjacent to the first source/drain region such that the channel region has a first voltage threshold region (Vt1) and a second voltage threshold region (Vt2) and such that the programmed cell operates at reduced drain source current.
    Type: Application
    Filed: February 2, 2006
    Publication date: March 19, 2009
    Inventors: Kirk Prall, Leonard Forbes
  • Publication number: 20090068812
    Abstract: Disclosed is a method of forming memory devices employing halogen ion implantation and diffusion processes. In one illustrative embodiment, the method includes forming a plurality of word line structures above a semiconducting substrate, each of the word line structures comprising a gate insulation layer, performing an LDD ion implantation process to form LDD doped regions in the substrate between the word line structures, performing a halogen ion implantation process to implant atoms of halogen into the semiconducting substrate between the word line structures, and performing at least one anneal process to cause at least some of the atoms of halogen to diffuse into the gate insulation layers on adjacent word line structures.
    Type: Application
    Filed: November 14, 2008
    Publication date: March 12, 2009
    Inventors: Kirk Prall, Behnam Moradi, Seiichi Aritome, Di Li, Chris Larsen
  • Patent number: 7485528
    Abstract: Disclosed is a method of forming memory devices employing halogen ion implantation and diffusion processes. In one illustrative embodiment, the method includes forming a plurality of word line structures above a semiconducting substrate, each of the word line structures comprising a gate insulation layer, performing an LDD ion implantation process to form LDD doped regions in the substrate between the word line structures, performing a halogen ion implantation process to implant atoms of halogen into the semiconducting substrate between the word line structures, and performing at least one anneal process to cause at least some of the atoms of halogen to diffuse into the gate insulation layers on adjacent word line structures.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: February 3, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Kirk Prall, Behnam Moradi, Seiichi Aritome, Di Li, Chris Larsen
  • Publication number: 20090010075
    Abstract: An array of memory cells configured to store at least one bit per one F2 includes substantially vertical structures providing an electronic memory function spaced apart a distance equal to one half of a minimum pitch of the array. The structures providing the electronic memory function are configured to store more than one bit per gate. The array also includes electrical contacts to the memory cells including the substantially vertical structures. The cells can be programmed to have one of a number of charge levels trapped in the gate insulator adjacent to the first source/drain region such that the channel region has a first voltage threshold region (Vt1) and a second voltage threshold region (Vt2) and such that the programmed cell operates at reduced drain source current.
    Type: Application
    Filed: February 2, 2006
    Publication date: January 8, 2009
    Inventors: Kirk Prall, Leonard Forbes
  • Publication number: 20080200005
    Abstract: An integrated circuit transistor is fabricated with a trench gate having nonconductive sidewalls. The transistor is surrounded by an isolation trench filled with a nonconductive material. The sidewalls of the gate trench are formed of the nonconductive material and are substantially free of unetched substrate material. As a result, the sidewalls of the gate trench do not form an undesired conductive path between the source and the drain of the transistor, thereby advantageously reducing the amount of parasitic current that flows between the source and drain during operation.
    Type: Application
    Filed: February 19, 2008
    Publication date: August 21, 2008
    Inventors: Michael Smith, Mark Helm, Kirk Prall
  • Patent number: 7332419
    Abstract: An integrated circuit transistor is fabricated with a trench gate having nonconductive sidewalls. The transistor is surrounded by an isolation trench filled with a nonconductive material. The sidewalls of the gate trench are formed of the nonconductive material and are substantially free of unetched substrate material. As a result, the sidewalls of the gate trench do not form an undesired conductive path between the source and the drain of the transistor, thereby advantageously reducing the amount of parasitic current that flows between the source and drain during operation.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: February 19, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Michael Smith, Mark Helm, Kirk Prall
  • Publication number: 20080014698
    Abstract: Disclosed is a method of forming memory devices employing halogen ion implantation and diffusion processes. In one illustrative embodiment, the method includes forming a plurality of word line structures above a semiconducting substrate, each of the word line structures comprising a gate insulation layer, performing an LDD ion implantation process to form LDD doped regions in the substrate between the word line structures, performing a halogen ion implantation process to implant atoms of halogen into the semiconducting substrate between the word line structures, and performing at least one anneal process to cause at least some of the atoms of halogen to diffuse into the gate insulation layers on adjacent word line structures.
    Type: Application
    Filed: July 14, 2006
    Publication date: January 17, 2008
    Inventors: Kirk Prall, Behnam Moradi, Seiichi Aritome, Di Li, Chris Larsen
  • Publication number: 20080009117
    Abstract: Non-volatile memory devices and arrays are described that facilitate the use of band-gap engineered gate stacks with asymmetric tunnel barriers in floating gate memory cells in NOR or NAND memory architectures that allow for direct tunneling programming and erase with electrons and holes, while maintaining high charge blocking barriers and deep carrier trapping sites for good charge retention. The direct tunneling program and erase capability reduces damage to the gate stack and the crystal lattice from high energy carriers, reducing write fatigue and leakage issues and enhancing device lifespan. Memory cells of the present invention also allow multiple bit storage in a single memory cell, and allow for programming and erase with reduced voltages. A positive voltage erase process via hole tunneling is also provided.
    Type: Application
    Filed: September 12, 2007
    Publication date: January 10, 2008
    Inventors: Arup Bhattacharyya, Kirk Prall, Luan Tran
  • Patent number: 7279710
    Abstract: An integrated circuit transistor is fabricated with a trench gate having nonconductive sidewalls. The transistor is surrounded by an isolation trench filled with a nonconductive material. The sidewalls of the gate trench are formed of the nonconductive material and are substantially free of unetched substrate material. As a result, the sidewalls of the gate trench do not form an undesired conductive path between the source and the drain of the transistor, thereby advantageously reducing the amount of parasitic current that flows between the source and drain during operation.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: October 9, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Michael Smith, Mark Helm, Kirk Prall
  • Publication number: 20070164348
    Abstract: Floating-gate field-effect transistors or memory cells formed in isolated wells are useful in the fabrication of non-volatile memory arrays and devices. A column of such floating-gate memory cells are associated with a well containing the source/drain regions for each memory cell in the column. These wells are isolated from source/drain regions of other columns of the array. Fowler-Nordheim tunneling can be used to program and erase such floating-gate memory cells either on an individual basis or on a bulk or block basis.
    Type: Application
    Filed: February 15, 2007
    Publication date: July 19, 2007
    Inventors: Chun Chen, Andrei Mihnea, Kirk Prall
  • Publication number: 20070111443
    Abstract: A method of forming a memory transistor includes providing a substrate comprising semiconductive material and forming spaced-apart source/drain structures. At least one of the source/drain structures forms a Schottky contact to the semiconductive material. The method also includes forming a memory gate between the spaced-apart source/drain structures and forming a control gate disposed operatively over the memory gate.
    Type: Application
    Filed: December 29, 2006
    Publication date: May 17, 2007
    Inventor: Kirk Prall
  • Patent number: 7199422
    Abstract: Floating-gate field-effect transistors or memory cells formed in isolated wells are useful in the fabrication of non-volatile memory arrays and devices. A column of such floating-gate memory cells are associated with a well containing the source/drain regions for each memory cell in the column. These wells are isolated from source/drain regions of other columns of the array. Fowler-Nordheim tunneling can be used to program and erase such floating-gate memory cells either on an individual basis or on a bulk or block basis.
    Type: Grant
    Filed: December 6, 2004
    Date of Patent: April 3, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Chun Chen, Andrei Mihnea, Kirk Prall
  • Publication number: 20070049030
    Abstract: Spacers in a pitch multiplication process are formed without performing a spacer etch. Rather, the mandrels are formed over a substrate and then the sides of the mandrels are reacted, e.g., in an oxidization, nitridation, or silicidation step, to form a material that can be selectively removed relative to the unreacted portions of the mandrel. The unreacted portions are selectively removed to leave a pattern of free-standing spacers. The free-standing spacers can serve as a mask for subsequent processing steps, such as etching the substrate.
    Type: Application
    Filed: September 1, 2005
    Publication date: March 1, 2007
    Inventors: Gurtej Sandhu, Kirk Prall
  • Publication number: 20060258090
    Abstract: Non-volatile memory devices and arrays are described that facilitate the use of band-gap engineered gate stacks with asymmetric tunnel barriers in floating gate memory cells in NOR or NAND memory architectures that allow for direct tunneling programming and erase with electrons and holes, while maintaining high charge blocking barriers and deep carrier trapping sites for good charge retention. The direct tunneling program and erase capability reduces damage to the gate stack and the crystal lattice from high energy carriers, reducing write fatigue and leakage issues and enhancing device lifespan. Memory cells of the present invention also allow multiple bit storage in a single memory cell, and allow for programming and erase with reduced voltages. A positive voltage erase process via hole tunneling is also provided.
    Type: Application
    Filed: May 12, 2005
    Publication date: November 16, 2006
    Inventors: Arup Bhattacharyya, Kirk Prall, Luan Tran
  • Patent number: 7115509
    Abstract: Methods and apparatus are described to facilitate forming memory devices with low resistance polysilicon local interconnects that allow a smaller array feature size and therefore facilitate forming arrays of a denser array format. Embodiments of the present invention are formed utilizing a wet etch process that has a high selectivity, allowing the deposition and etching of polysilicon local interconnects to source regions of array transistors. By providing for a local interconnect of polysilicon, a smaller source region and/or drain region can also be utilized, further decreasing the required word line spacing. Low resistance polysilicon local source interconnects can also couple to an increased number of memory cells, thereby reducing the number of contacts made to an array ground.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: October 3, 2006
    Assignee: Micron Technology, Inc.
    Inventors: Chun Chen, Guy Blalock, Graham Wolstenholme, Kirk Prall
  • Publication number: 20060208310
    Abstract: A method for forming a flash memory device having a local interconnect connecting source regions of a plurality of transistors within a sector allows for a highly selective wet etch of a dielectric region overlying the source region. An embodiment of the method comprises the use of an etch-resistant layer covering various features such as any gate oxide remaining over the source region, spacers along sidewalls of the transistor stacks, and a capping layer of the transistor. An in-process semiconductor device resulting from the inventive method is also disclosed.
    Type: Application
    Filed: May 24, 2006
    Publication date: September 21, 2006
    Inventors: Kirk Prall, Chun Chen
  • Publication number: 20060203555
    Abstract: A multi-state NAND memory cell is comprised of two drain/source areas in a substrate. An oxide-nitride-oxide structure is formed above the substrate between the drain/source areas. The nitride layer acting as an asymmetric charge trapping layer. A control gate is located above the oxide-nitride-oxide structure. An asymmetrical bias on the drain/source areas causes the drain/source area with the higher voltage to inject an asymmetric distribution hole by gate induced drain leakage injection into the trapping layer substantially adjacent that drain/source area.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 14, 2006
    Inventor: Kirk Prall
  • Publication number: 20060203554
    Abstract: A multi-state NAND memory cell is comprised of two drain/source areas in a substrate. An oxide-nitride-oxide structure is formed above the substrate between the drain/source areas. The nitride layer acting as an asymmetric charge trapping layer. A control gate is located above the oxide-nitride-oxide structure. An asymmetrical bias on the drain/source areas causes the drain/source area with the higher voltage to inject an asymmetric distribution hole by gate induced drain leakage injection into the trapping layer substantially adjacent that drain/source area.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 14, 2006
    Inventor: Kirk Prall