Patents by Inventor Hiroshi Sakuraba

Hiroshi Sakuraba 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: 7387935
    Abstract: A memory cell unit including: a semiconductor substrate having a source diffusion layer in at least a part of a surface thereof; a column-shaped semiconductor layer provided on the semiconductor substrate, and having a drain diffusion layer provided in an uppermost portion thereof and a first low concentration impurity diffusion layer provided in an entire bottom portion thereof; a memory cell arrangement which includes a plurality of memory cells provided in a peripheral wall of the column-shaped semiconductor layer and connected in series perpendicularly to the substrate, the memory cells each having a charge storage layer and a control gate; a second impurity diffusion layer provided at a lower end of the memory cell arrangement; and a selection transistor having a gate electrode provided around the peripheral wall of the column-shaped semiconductor layer and connecting the second impurity diffusion layer and the first impurity diffusion layer; wherein the first impurity diffusion layer extends into a part
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: June 17, 2008
    Assignees: Sharp Kabushiki Kaisha
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno, Ryusuke Matsuyama, Shinji Horii, Takuji Tanigami
  • Patent number: 7088617
    Abstract: A nonvolatile semiconductor storage device including: a plurality of memory cell unit groups each comprising one or more NAND nonvolatile memory cell units each comprising at least one memory cell having a control gate, a first selection transistor having a first selection gate, and a second selection transistor having a second selection gate, the memory cell unit groups each further comprising a control gate line connected to the control gate, a first selection gate line connected to the first selection gate, and a second selection gate line connected to the second selection gate; a common control gate line connected commonly to the control gate lines of different ones of the memory cell unit groups; a first common selection gate line connected commonly to the first selection gate lines of different ones of the memory cell unit groups; and a second common selection gate line connected commonly to the second selection gate lines of different ones of the memory cell unit groups; wherein the memory cells in the
    Type: Grant
    Filed: August 16, 2004
    Date of Patent: August 8, 2006
    Assignees: Sharp Kabushiki Kaisha, Fujio Masuoka
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno, Ryusuke Matsuyama, Shinji Horii
  • Patent number: 7009888
    Abstract: A method for driving a nonvolatile memory device including a semiconductor substrate, an island semiconductor layer on the substrate, a memory cell having a control gate and a charge storage layer surrounding a peripheral surface of the island semiconductor layer, a first selection transistor provided between the memory cell and the substrate and having a first selection gate, a source diffusion layer between the substrate and the island semiconductor layer, a drain diffusion layer provided in an opposing end of the island semiconductor layer from the source diffusion layer, and a second selection transistor provided between the memory cell and the drain diffusion layer and having a second selection gate, the method comprising the steps of: applying a negative first voltage to the drain and the first selection gate, applying a positive second voltage to the second selection gate, and applying 0V or a positive third voltage to the source; and applying a positive fourth voltage higher than the second voltage to
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: March 7, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno, Ryusuke Matsuyama, Shinji Horii
  • Publication number: 20050063237
    Abstract: A memory cell unit including: a semiconductor substrate having a source diffusion layer in at least a part of a surface thereof; a column-shaped semiconductor layer provided on the semiconductor substrate, and having a drain diffusion layer provided in an uppermost portion thereof and a first low concentration impurity diffusion layer provided in an entire bottom portion thereof; a memory cell arrangement which includes a plurality of memory cells provided in a peripheral wall of the column-shaped semiconductor layer and connected in series perpendicularly to the substrate, the memory cells each having a charge storage layer and a control gate; a second impurity diffusion layer provided at a lower end of the memory cell arrangement; and a selection transistor having a gate electrode provided around the peripheral wall of the column-shaped semiconductor layer and connecting the second impurity diffusion layer and the first impurity diffusion layer; wherein the first impurity diffusion layer extends into a part
    Type: Application
    Filed: September 14, 2004
    Publication date: March 24, 2005
    Applicants: Fujio MASUOKA, SHARP KABUSHIKI KAISHA
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno, Ryusuke Matsuyama, Shinji Horii, Takuji Tanigami
  • Publication number: 20050051806
    Abstract: A memory cell unit including: a semiconductor substrate having a source diffusion layer provided in a surface thereof; a column-shaped semiconductor layer provided on the source diffusion layer and having a drain diffusion layer provided in an uppermost portion thereof; a memory cell arrangement which includes a plurality of memory cells arranged in series with the intervention of a first impurity diffusion layer; a first selection transistor connected to one end of the memory cell arrangement with the intervention of a second impurity diffusion layer and connected to the drain diffusion layer; and a second selection transistor connected to the other end of the memory cell arrangement with the intervention of a third impurity diffusion layer and connected to the source diffusion layer; wherein a distance between the third impurity diffusion layer and the source diffusion layer is greater than a distance between impurity diffusion layers disposed on opposite sides of each of the memory cells, whereby punch-thr
    Type: Application
    Filed: August 30, 2004
    Publication date: March 10, 2005
    Applicants: FUJIO MASUOKA, SHARP KABUSHIKI KAISHA
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno
  • Publication number: 20050047209
    Abstract: A nonvolatile semiconductor storage device including: a plurality of memory cell unit groups each comprising one or more NAND nonvolatile memory cell units each comprising at least one memory cell having a control gate, a first selection transistor having a first selection gate, and a second selection transistor having a second selection gate, the memory cell unit groups each further comprising a control gate line connected to the control gate, a first selection gate line connected to the first selection gate, and a second selection gate line connected to the second selection gate; a common control gate line connected commonly to the control gate lines of different ones of the memory cell unit groups; a first common selection gate line connected commonly to the first selection gate lines of different ones of the memory cell unit groups; and a second common selection gate line connected commonly to the second selection gate lines of different ones of the memory cell unit groups; wherein the memory cells in the
    Type: Application
    Filed: August 16, 2004
    Publication date: March 3, 2005
    Applicants: Fujio Masuoka, SHARP KABUSHIKI KAISHA
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno, Ryusuke Matsuyama, Shinji Horii
  • Publication number: 20050012134
    Abstract: A method for driving a nonvolatile memory device including a semiconductor substrate, an island semiconductor layer on the substrate, a memory cell having a control gate and a charge storage layer surrounding a peripheral surface of the island semiconductor layer, a first selection transistor provided between the memory cell and the substrate and having a first selection gate, a source diffusion layer between the substrate and the island semiconductor layer, a drain diffusion layer provided in an opposing end of the island semiconductor layer from the source diffusion layer, and a second selection transistor provided between the memory cell and the drain diffusion layer and having a second selection gate, the method comprising the steps of: applying a negative first voltage to the drain and the first selection gate, applying a positive second voltage to the second selection gate, and applying 0V or a positive third voltage to the source; and applying a positive fourth voltage higher than the second voltage to
    Type: Application
    Filed: July 8, 2004
    Publication date: January 20, 2005
    Applicants: Fujio Masuoka, SHARP KABUSHIKI KAISHA
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Fumiyoshi Matsuoka, Syounosuke Ueno, Ryusuke Matsuyama, Shinji Horii
  • Publication number: 20040262681
    Abstract: A semiconductor device including: a silicon pillar having a high-resistivity region and first and second highly doped regions sandwiching the high-resistivity region therebetween, the high-resistivity region having an impurity concentration of 1017 cm−3 or less; an insulator surrounding the high-resistivity region; and a conductor surrounding the insulator, wherein the conductor is made of a material which permits a voltage applied to the conductor to control an electric current flowing between the first and second highly doped regions and which has a work function bringing the high-resistivity region to a perfect depletion condition during the flow of the electric current between the first and second highly doped regions.
    Type: Application
    Filed: May 25, 2004
    Publication date: December 30, 2004
    Applicants: FUJIO MASUOKA, SHARP KABUSHIKI KAISHA
    Inventors: Fujio Masuoka, Hiroshi Sakuraba, Yasue Yamamoto