Patents by Inventor Roger R. Lee

Roger R. Lee 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).

  • Publication number: 20010021549
    Abstract: Floating gate transistors and methods of forming the same are described. In one implementation, a floating gate is formed over a substrate. The floating gate has an inner first portion and an outer second portion. Conductivity enhancing impurity is provided in the inner first portion to a greater concentration than conductivity enhancing impurity in the outer second portion. In another implementation, the floating gate is formed from a first layer of conductively doped semiconductive material and a second layer of substantially undoped semiconductive material. In another implementation, the floating gate is formed from a first material having a first average grain size and a second material having a second average grain size which is larger than the first average grain size.
    Type: Application
    Filed: July 17, 1998
    Publication date: September 13, 2001
    Inventors: J. DENNIS KELLER, ROGER R. LEE
  • Patent number: 6281091
    Abstract: Disclosed is a container capacitor structure and method of constructing it. An etch mask and etch are used to expose portions of an exterior surface of electrode (“bottom electrodes”) of the container capacitor structure. The etch provides a recess between proximal pairs of container capacitor structures, which recess is available for forming additional capacitance. Accordingly, a capacitor dielectric and a top electrode are formed on and adjacent to, respectively, both an interior surface and portions of the exterior surface of the first electrode. Advantageously, surface area common to both the first electrode and second electrodes is increased over using only the interior surface, which provides additional capacitance without a decrease in spacing for clearing portions of the capacitor dielectric and the second electrode away from a contact hole location.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: August 28, 2001
    Assignee: Micron Technology, Inc.
    Inventors: D. Mark Durcan, Trung T. Doan, Roger R. Lee, Fernando Gonzalez
  • Patent number: 6243299
    Abstract: A flash memory system powered by an external primary voltage source, with the system including an array of flash memory cells arranged in rows and columns, with each of the cells including a source region, a drain region, a channel region intermediate the drain and source region, a floating gate disposed over the channel region and a control gate disposed over the floating gate, with the cells located in one of the array columns having their drains connected to a common bit line and with the cells in one of the rows having their control gates connected to a common word line. The memory system includes a control circuit carrying out read, programming and erase operations. The erase operation is performed by applying a negative voltage to control gate of the cell being erased and a positive voltage to the source of the cells being erased.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: June 5, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Darrell D. Rinerson, Roger R. Lee, Christophe J. Chevallier
  • Patent number: 6184096
    Abstract: A semiconductor processing method of providing dopant impurity into a semiconductor substrate includes: a) providing a semiconductor substrate, the substrate comprising a first bulk region having a blanket doping of a first conductivity type dopant, the substrate comprising a second bulk region having a blanket doping of a second conductivity type dopant; b) defining field oxide regions and active area regions in each of the first and second bulk substrate regions; c) in the same masking step, masking active area regions of the first bulk substrate region while leaving field oxide regions of the first bulk substrate region unmasked and masking field oxide regions of the second bulk substrate region while leaving select active area regions of the second bulk substrate region unmasked; and d) in the same ion implanting step, ion implanting first conductivity type impurity through the unmasked portions of the first and second bulk substrate regions to simultaneously form channel stop isolation implants beneath t
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: February 6, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Roger R. Lee, Charles H. Dennison
  • Patent number: 6159818
    Abstract: Disclosed is a container capacitor structure and method of constructing it. An etch mask and etch are used to expose portions of an exterior surface of electrode ("bottom electrodes") of the container capacitor structure. The etch provides a recess between proximal pairs of container capacitor structures, which recess is available for forming additional capacitance. Accordingly, a capacitor dielectric and a top electrode are formed on and adjacent to, respectively, both an interior surface and portions of the exterior surface of the first electrode. Advantageously, surface area common to both the first electrode and second electrodes is increased over using only the interior surface, which provides additional capacitance without a decrease in spacing for clearing portions of the capacitor dielectric and the second electrode away from a contact hole location.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: December 12, 2000
    Assignee: Micron Technology, Inc.
    Inventors: D. Mark Durcan, Trung T. Doan, Roger R. Lee, Fernando Gonzalez, Er-Xuan Ping
  • Patent number: 5989980
    Abstract: A semiconductor processing method of forming field isolation oxide relative to a semiconductor substrate includes providing a semiconductor substrate having field and active area regions; forming masking material over the active area region and leaving the field region exposed, the masking material comprising first, second and third layers, and having a sidewall; exposing the semiconductor substrate to first oxidation conditions effective to form field isolation oxide of a first thickness over the exposed field region; forming an etch stop material layer over the sidewall; removing at least a portion of the third layer selectively relative to the etch stop material layer; and subjecting the semiconductor substrate to second oxidation conditions effective to grow the field isolation oxide to a second thickness on the exposed field region of the semiconductor substrate.
    Type: Grant
    Filed: November 25, 1997
    Date of Patent: November 23, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Roger R. Lee, Fernando Gonzalez
  • Patent number: 5985719
    Abstract: A method of reducing undesired electron depletion through sidewalls of a floating gate of a floating gate transistor comprising providing a non-oxide or oxynitride layer over said sidewalls. Integrated circuitry including a non-volatile field effect transistor includes, a) a floating gate transistor having a gate construction and a pair of opposing source/drain regions, the gate construction having at least one sidewall; b) a shielding layer over the gate sidewall; and c) a dielectric layer on the shielding layer, the dielectric layer being of a different material than the shielding layer. The shielding layer might be provided over an oxide layer previously provided on sidewalls of the gate construction. The shielding layer might be provided over sidewall spacers previously provided relative to sidewalls of the gate construction. Example and preferred shielding layer materials include Si.sub.3 N.sub.4, oxynitride compounds, and aluminum.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: November 16, 1999
    Assignee: Micron Technology, Inc.
    Inventors: J. Dennis Keller, Roger R. Lee
  • Patent number: 5981338
    Abstract: A method of forming a line for floating gate transistors is described and which includes, providing a substrate having a plurality of discrete field oxide regions, and intervening active area regions therebetween; forming a first alternating series of floating gates over a first alternating series of active area regions; forming a second alternating series of floating gates over a second alternating series of active area regions, the second series of floating gates disposed in spaced, overlapping and partial covering relation relative to the first alternating series of floating gates; forming a layer of dielectric material over the first and second series of floating gates; and forming a control gate layer of electrically conductive material over the layer of dielectric material. The present invention further relates to a memory chip, and die having a line of floating gate transistors formed from the same method.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: November 9, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5936275
    Abstract: A method of forming a line for floating gate transistors is described and which includes, providing a substrate having a plurality of discrete field oxide regions, and intervening active area regions therebetween; forming a first alternating series of floating gates over a first alternating series of active area regions; forming a second alternating series of floating gates over a second alternating series of active area regions, the second series of floating gates disposed in spaced, overlapping and partial covering relation relative to the first alternating series of floating gates; forming a layer of dielectric material over the first and second series of floating gates; and forming a control gate layer of electrically conductive material over the layer of dielectric material. The present invention further relates to a memory chip, and die having a line of floating gate transistors formed from the same method.
    Type: Grant
    Filed: December 11, 1997
    Date of Patent: August 10, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5917755
    Abstract: A flash memory system powered by an external primary voltage source, with the system including an array of flash memory cells arranged in rows and columns, with each of the cells including a source region, a drain region, a channel region intermediate the drain and source region, a floating gate disposed over the channel region and a control gate disposed over the floating gate, with the cells located in one of the array columns having their drains connected to a common bit line and with the cells in one of the rows having their control gates connected to a common word line. The memory system includes a control circuit carrying out read, programming and erase operations. The erase operation is performed by applying a negative voltage to control gate of the cell being erased and a positive voltage to the source of the cells being erased.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: June 29, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Darrell D. Rinerson, Roger R. Lee, Christophe J. Chevallier
  • Patent number: 5904532
    Abstract: A semiconductor processing method of providing dopant impurity into a semiconductor substrate includes: a) providing a semiconductor substrate, the substrate comprising a first bulk region having a blanket doping of a first conductivity type dopant, the substrate comprising a second bulk region having a blanket doping of a second conductivity type dopant; b) defining field oxide regions and active area regions in each of the first and second bulk substrate regions; c) in the same masking step, masking active area regions of the first bulk substrate region while leaving field oxide regions of the first bulk substrate region unmasked and masking field oxide regions of the second bulk substrate region while leaving select active area regions of the second bulk substrate region unmasked; and d) in the same ion implanting step, ion implanting first conductivity type impurity through the unmasked portions of the first and second bulk substrate regions to simultaneously form channel stop isolation implants beneath t
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: May 18, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Roger R. Lee, Charles H. Dennison
  • Patent number: 5781477
    Abstract: A flash memory system powered by an external primary voltage source, with the system including an array of flash memory cells arranged in rows and columns, with each of the cells including a source region, a drain region, a channel region intermediate the drain and source region, a floating gate disposed over the channel region and a control gate disposed over the floating gate, with the cells located in one of the array columns having their drains connected to a common bit line and with the cells in one of the rows having their control gates connected to a common word line. The memory system includes a control circuit carrying out read, programming and erase operations. The erase operation is performed by applying a negative voltage to control gate of the cell being erased and a positive voltage to the source of the cells being erased.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: July 14, 1998
    Assignee: Micron Quantum Devices, Inc.
    Inventors: Darrell D. Rinerson, Roger R. Lee, Christophe J. Chevallier
  • Patent number: 5748527
    Abstract: A flash memory array comprises a primary row line and a redundant row line each having memory cells therealong. A method of accessing the flash memory array comprises preprogramming all said memory cells. Next, all memory cells are erased simultaneously. Subsequently, all memory cells along the primary row line are programmed and the cells along the redundant row line are selectively programmed. The primary row line is bypassed during any read cycle.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: May 5, 1998
    Assignee: Micron Technology, Inc.
    Inventors: Roger R. Lee, Fernando Gonzalez
  • Patent number: 5726471
    Abstract: A method of reducing undesired electron depletion through sidewalls of a floating gate of a floating gate transistor comprising providing a non-oxide or oxynitride layer over said sidewalls. Integrated circuitry including a non-volatile field effect transistor includes, a) a floating gate transistor having a gate construction and a pair of opposing source/drain regions, the gate construction having at least one sidewall; b) a shielding layer over the gate sidewall; and c) a dielectric layer on the shielding layer, the dielectric layer being of a different material than the shielding layer. The shielding layer might be provided over an oxide layer previously provided on sidewalls of the gate construction. The shielding layer might be provided over sidewall spacers previously provided relative to sidewalls of the gate construction. Example and preferred shielding layer materials include Si.sub.3 N.sub.4, oxynitride compounds, and aluminum.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: March 10, 1998
    Assignee: Micron Technology, Inc.
    Inventors: J. Dennis Keller, Roger R. Lee
  • Patent number: 5721441
    Abstract: A method of forming a line for floating gate transistors is described and which includes, providing a substrate having a plurality of discrete field oxide regions, and intervening active area regions therebetween; forming a first alternating series of floating gates over a first alternating series of active area regions; forming a second alternating series of floating gates over a second alternating series of active area regions, the second series of floating gates disposed in spaced, overlapping and partial covering relation relative to the first alternating series of floating gates; forming a layer of dielectric material over the first and second series of floating gates; and forming a control gate layer of electrically conductive material over the layer of dielectric material. The present invention further relates to a memory chip, and die having a line of floating gate transistors formed from the same method.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: February 24, 1998
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5714414
    Abstract: A semiconductor processing method of forming field isolation oxide relative to a semiconductor substrate includes providing a semiconductor substrate having field and active area regions; forming masking material over the active area region and leaving the field region exposed, the masking material comprising first, second and third layers, and having a sidewall; exposing the semiconductor substrate to first oxidation conditions effective to form field isolation oxide of a first thickness over the exposed field region; forming an etch stop material layer over the sidewall; removing at least a portion of the third layer selectively relative to the etch stop material layer; and subjecting the semiconductor substrate to second oxidation conditions effective to grow the field isolation oxide to a second thickness on the exposed field region of the semiconductor substrate.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: February 3, 1998
    Assignee: Micron Technology, Inc.
    Inventors: Roger R. Lee, Fernando Gonzalez
  • Patent number: 5707898
    Abstract: A method of reducing undesired electron depletion through sidewalls of a floating gate of a floating gate transistor comprising providing a non-oxide or oxynitride layer over said sidewalls. Integrated circuitry including a non-volatile field effect transistor includes, a) a floating gate transistor having a gate construction and a pair of opposing source/drain regions, the gate construction having at least one sidewall; b) a shielding layer over the gate sidewall; and c) a dielectric layer on the shielding layer, the dielectric layer being of a different material than the shielding layer. The shielding layer might be provided over an oxide layer previously provided on sidewalls of the gate construction. The shielding layer might be provided over sidewall spacers previously provided relative to sidewalls of the gate construction. Example and preferred shielding layer materials include Si.sub.3 N.sub.4, oxynitride compounds, and aluminum.
    Type: Grant
    Filed: April 1, 1996
    Date of Patent: January 13, 1998
    Assignee: Micron Technology, Inc.
    Inventors: J. Dennis Keller, Roger R. Lee
  • Patent number: 5700730
    Abstract: A semiconductor processing method of providing dopant impurity into a semiconductor substrate includes: a) providing a semiconductor substrate, the substrate comprising a first bulk region having a blanket doping of a first conductivity type dopant, the substrate comprising a second bulk region having a blanket doping of a second conductivity type dopant; b) defining field oxide regions and active area regions in each of the first and second bulk substrate regions; c) in the same masking step, masking active area regions of the first bulk substrate region while leaving field oxide regions of the first bulk substrate region unmasked and masking field oxide regions of the second bulk substrate region while leaving select active area regions of the second bulk substrate region unmasked; and d) in the same ion implanting step, ion implanting first conductivity type impurity through the unmasked portions of the first and second bulk substrate regions to simultaneously form channel stop isolation implants beneath t
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: December 23, 1997
    Assignee: Micron Technology, Inc.
    Inventors: Roger R. Lee, Charles H. Dennison
  • Patent number: 5680350
    Abstract: This invention constitutes a method for narrowing threshold voltage distribution among the individual cells of a block erased flash memory array by firstly, preprogramming cells within the block be erased to a level of saturation using hot electron injection to drive a surplus of electrons into the floating gate of each cell; secondly, subjecting all cells with the block to a first erase pulse which causes the surplus electrons within the floating gate of each cell to be driven into the cell's source region via Fowler-Nordheim tunneling, with the erase pulse being of sufficient length to erase every cell within the block; thirdly, subjecting all cells within the block to a word line stress step or a soft programming step, by means of which some electrons are driven back into the floating gate of each cell via Fowler-Nordheim tunneling or hot electron injection, respectively; and, fourthly, subjecting all cells within the block to a second erase pulse, the second erase pulse being at least an order of magnitud
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: October 21, 1997
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5658814
    Abstract: A method of forming a line for floating gate transistors is described and which includes, providing a substrate having a plurality of discrete field oxide regions, and intervening active area regions therebetween; forming a first alternating series of floating gates over a first alternating series of active area regions; forming a second alternating series of floating gates over a second alternating series of active area regions, the second series of floating gates disposed in spaced, overlapping and partial covering relation relative to the first alternating series of floating gates; forming a layer of dielectric material over the first and second series of floating gates; and forming a control gate layer of electrically conductive material over the layer of dielectric material. The present invention further relates to a memory chip, and die having a line of floating gate transistors formed from the same method.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: August 19, 1997
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee