Patents by Inventor Hiroaki Hazama

Hiroaki Hazama 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: 8879326
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Grant
    Filed: June 17, 2013
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Hazama, Norio Ohtani
  • Patent number: 8837225
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate and memory transistors, each of which has a laminate formed by alternately laminating insulating films and conductive films on the semiconductor substrate, a silicon pillar going through the laminate, a tunnel insulating film arranged on the surface of the silicon pillar facing the laminate, a charge accumulating layer arranged on the surface of the tunnel insulating film facing the laminate, and a block insulating film arranged on the surface of the charge accumulating layer facing the laminate and in contact with the conductive film. During a data deletion operation, a voltage is applied on the conductive film so that the potential of the silicon pillar with respect to the conductive film decreases as the cross-sectional area of the silicon pillar decreases.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: September 16, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masaaki Higuchi, Katsuyuki Sekine, Ryota Katsumata, Hiroaki Hazama
  • Publication number: 20140010016
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate and memory transistors, each of which has a laminate formed by alternately laminating insulating films and conductive films on the semiconductor substrate, a silicon pillar going through the laminate, a tunnel insulating film arranged on the surface of the silicon pillar facing the laminate, a charge accumulating layer arranged on the surface of the tunnel insulating film facing the laminate, and a block insulating film arranged on the surface of the charge accumulating layer facing the laminate and in contact with the conductive film. During a data deletion operation, a voltage is applied on the conductive film so that the potential of the silicon pillar with respect to the conductive film decreases as the cross-sectional area of the silicon pillar decreases.
    Type: Application
    Filed: March 6, 2013
    Publication date: January 9, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masaaki HIGUCHI, Katsuyuki SEKINE, Ryota KATSUMATA, Hiroaki HAZAMA
  • Publication number: 20130279261
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Application
    Filed: June 17, 2013
    Publication date: October 24, 2013
    Inventors: Hiroaki Hazama, Norio Ohtani
  • Patent number: 8482984
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: July 9, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Hazama, Norio Ohtani
  • Patent number: 8363480
    Abstract: A nonvolatile semiconductor storage device including a NAND cell unit having a first and a second select gate transistor, a plurality of memory cell transistors series connected between the first and second select gate transistors that are coupled to corresponding word lines, and a peripheral circuit erase verifying the NAND cell unit by turning on the first and second select gate transistors, applying a predetermined voltage level on the source line, making a voltage level applied on one or more of the word lines coupled to the memory cell transistors relatively closer to the second select gate transistor larger than that applied on one or more of the word lines coupled to the memory cell transistors relatively closer to the first select gate transistor, and verifying data erase of the memory cell transistors.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: January 29, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroaki Hazama
  • Publication number: 20120262989
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Application
    Filed: June 22, 2012
    Publication date: October 18, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki HAZAMA, Norio Ohtani
  • Patent number: 8274834
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Grant
    Filed: February 7, 2011
    Date of Patent: September 25, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Hazama, Norio Ohtani
  • Patent number: 8222106
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate, a plurality of first element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a first cell array region into a band shape, a plurality of second element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a second cell array region into a band shape. Each first element isolation insulating film has a level from a surface of the semiconductor substrate, the first charge storage layer has a level from the surface of the semiconductor substrate, and each second element isolation insulating film has a level from the surface of the semiconductor substrate, the level of each first element isolation insulating film being lower than the level of the first charge storage layer and higher than the level of each second element isolation insulating film.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: July 17, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroaki Hazama
  • Publication number: 20120127803
    Abstract: A nonvolatile semiconductor storage device including a NAND cell unit having a first and a second select gate transistor, a plurality of memory cell transistors series connected between the first and second select gate transistors that are coupled to corresponding word lines, and a peripheral circuit erase verifying the NAND cell unit by turning on the first and second select gate transistors, applying a predetermined voltage level on the source line, making a voltage level applied on one or more of the word lines coupled to the memory cell transistors relatively closer to the second select gate transistor larger than that applied on one or more of the word lines coupled to the memory cell transistors relatively closer to the first select gate transistor, and verifying data erase of the memory cell transistors.
    Type: Application
    Filed: January 27, 2012
    Publication date: May 24, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Hiroaki HAZAMA
  • Publication number: 20120077328
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate, a plurality of first element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a first cell array region into a band shape, a plurality of second element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a second cell array region into a band shape. Each first element isolation insulating film has a level from a surface of the semiconductor substrate, the first charge storage layer has a level from the surface of the semiconductor substrate, and each second element isolation insulating film has a level from the surface of the semiconductor substrate, the level of each first element isolation insulating film being lower than the level of the first charge storage layer and higher than the level of each second element isolation insulating film.
    Type: Application
    Filed: December 1, 2011
    Publication date: March 29, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Hiroaki Hazama
  • Patent number: 8130555
    Abstract: A nonvolatile semiconductor storage device including a NAND cell unit having a first and a second select gate transistor, a plurality of memory cell transistors series connected between the first and second select gate transistors that are coupled to corresponding word lines, and a peripheral circuit erase verifying the NAND cell unit by turning on the first and second select gate transistors, applying a predetermined voltage level on the source line, detecting a voltage level of the bit line at once under a state where a voltage level applied on one or more of the word lines coupled to the memory cell transistors relatively closer to the second select gate transistor is arranged higher than that applied on one or more of the word lines coupled to the memory cell transistors relatively closer to the first select gate transistor, and verifying data erase based on the detected voltage.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: March 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroaki Hazama
  • Patent number: 8098509
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate, a plurality of first element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a first cell array region into a band shape, a plurality of second element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a second cell array region into a band shape. Each first element isolation insulating film has a level from a surface of the semiconductor substrate, the first charge storage layer has a level from the surface of the semiconductor substrate, and each second element isolation insulating film has a level from the surface of the semiconductor substrate, the level of each first element isolation insulating film being lower than the level of the first charge storage layer and higher than the level of each second element isolation insulating film.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: January 17, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroaki Hazama
  • Publication number: 20110128789
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Application
    Filed: February 7, 2011
    Publication date: June 2, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Hazama, Norio Ootani
  • Patent number: 7898867
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Grant
    Filed: December 28, 2009
    Date of Patent: March 1, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Hazama, Norio Ohtani
  • Publication number: 20100265767
    Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate, a plurality of first element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a first cell array region into a band shape, a plurality of second element isolation insulating films formed on a surface of the semiconductor substrate corresponding to a second cell array region into a band shape. Each first element isolation insulating film has a level from a surface of the semiconductor substrate, the first charge storage layer has a level from the surface of the semiconductor substrate, and each second element isolation insulating film has a level from the surface of the semiconductor substrate, the level of each first element isolation insulating film being lower than the level of the first charge storage layer and higher than the level of each second element isolation insulating film.
    Type: Application
    Filed: September 18, 2009
    Publication date: October 21, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Hiroaki HAZAMA
  • Patent number: 7795667
    Abstract: A semiconductor device comprises a non-volatile memory including a memory cell array, element isolating regions, a second trench and a word line. The memory cell array is constituted by memory cells which have floating electrodes and are arranged in the shape of a matrix on a semiconductor substrate. Each of the element isolating regions has a first trench formed in the semiconductor substrate and between memory cells adjacent to each other along a gate width direction, and an isolating filler filled in the first trench. The second trench is formed in the isolating filler and between the floating electrodes of the memory cells adjacent to each other along the gate width direction, and is narrow at the bottom thereof. The word line is connected to the memory cells, buried in the second trenches and extending along the gate width direction.
    Type: Grant
    Filed: July 3, 2003
    Date of Patent: September 14, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadashi Iguchi, Katsuhiro Ishida, Hiroaki Tsunoda, Hirohisa Iizuka, Hiroaki Hazama, Seiichi Mori
  • Patent number: 7786524
    Abstract: A semiconductor device includes a semiconductor substrate including a first region and a second region being adjacent to the first region; a floating gate electrode layer formed above the semiconductor substrate in the first region, the floating gate electrode layer including a first width; a dummy gate electrode layer formed above the semiconductor substrate in the second region, the dummy gate electrode layer including a second width being greater than the first width of the floating gate electrode layer; a first gate insulating film formed on the floating gate electrode layer, the first gate insulating film including a first thickness; a second gate insulating film formed on the dummy gate electrode layer, the second gate insulating film including a second thickness being greater than the first thickness of the first gate insulating film; and a control gate electrode layer formed on the first and the second gate insulating films.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: August 31, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroaki Hazama
  • Publication number: 20100103741
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cells.
    Type: Application
    Filed: December 28, 2009
    Publication date: April 29, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki HAZAMA, Norio Ootani
  • Patent number: 7692969
    Abstract: A nonvolatile semiconductor memory device having a plurality of electrically rewritable nonvolatile memory cells connected in series together includes a select gate transistor connected in series to the serial combination of memory cells. A certain one of the memory cells which is located adjacent to the select gets transistor is for use as a dummy cell. This dummy cell is not used for data storage. During data erasing, the dummy cell is applied with the same bias voltage as that for the other memory cell.
    Type: Grant
    Filed: March 23, 2009
    Date of Patent: April 6, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroaki Hazama, Norio Ohtani