Patents by Inventor Toshitake Yaegashi

Toshitake Yaegashi 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: 10797065
    Abstract: A nonvolatile semiconductor storage device including a number of memory cells formed on a semiconductor substrate, each of the memory cells has a tunnel insulating film, a charge storage layer, a block insulating film, and a gate electrode which are formed in sequence on the substrate. The gate electrode is structured such that at least first and second gate electrode layers are stacked. The dimension in the direction of gate length of the second gate electrode layer, which is formed on the first gate electrode layer, is smaller than the dimension in the direction of gate length of the first gate electrode layer.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: October 6, 2020
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventor: Toshitake Yaegashi
  • Publication number: 20170221918
    Abstract: A nonvolatile semiconductor storage device including a number of memory cells formed on a semiconductor substrate, each of the memory cells has a tunnel insulating film, a charge storage layer, a block insulating film, and a gate electrode which are formed in sequence on the substrate. The gate electrode is structured such that at least first and second gate electrode layers are stacked. The dimension in the direction of gate length of the second gate electrode layer, which is formed on the first gate electrode layer, is smaller than the dimension in the direction of gate length of the first gate electrode layer.
    Type: Application
    Filed: April 19, 2017
    Publication date: August 3, 2017
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Toshitake YAEGASHI
  • Patent number: 9691779
    Abstract: A nonvolatile semiconductor storage device including a number of memory cells formed on a semiconductor substrate, each of the memory cells has a tunnel insulating film, a charge storage layer, a block insulating film, and a gate electrode which are formed in sequence on the substrate. The gate electrode is structured such that at least first and second gate electrode layers are stacked. The dimension in the direction of gate length of the second gate electrode layer, which is formed on the first gate electrode layer, is smaller than the dimension in the direction of gate length of the first gate electrode layer.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: June 27, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventor: Toshitake Yaegashi
  • Publication number: 20160064409
    Abstract: A non-volatile semiconductor storage device includes a plurality of gate electrodes stacked in a first direction, a channel portion facing the gate electrodes and extending in the first direction, and first and second charge storage layers between the gate electrode and the channel portion in a second direction crossing the first direction, wherein the second charge storage layer has portions that are between the gate electrodes in the first direction.
    Type: Application
    Filed: July 28, 2015
    Publication date: March 3, 2016
    Inventor: Toshitake YAEGASHI
  • Publication number: 20150261603
    Abstract: The word line includes a first word line which is connected to the memory cell configured capable of storing data of a first bit number and a second word line which is connected to the memory cell configured capable of storing data of a second bit number which is smaller than the first bit number. The control circuit is configured to store in the memory cell connected to the first word line user data capable of being arbitrarily rewritten by a user and a parity for performing error correction on the user data. The control circuit is configured to store in the memory cell connected to the second word line not only the parity but also a first external parity for performing error correction on the user data.
    Type: Application
    Filed: June 2, 2014
    Publication date: September 17, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toshitake YAEGASHI, Osamu TORII
  • Publication number: 20150256204
    Abstract: According to one embodiment, a memory controller includes a first encoder configured to generate a first codeword by encoding first data and generate a second codeword by encoding second data; an operation unit configured to perform an exor operation with at least the first codeword and the second codeword as inputs to generate a first exor-codeword; and a second encoder configured to encode the first exor-codeword to generate a second-stage parity; wherein the first codeword, the second codeword, and the second-stage parity are written to a nonvolatile memory.
    Type: Application
    Filed: August 6, 2014
    Publication date: September 10, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Osamu TORII, Toshitake YAEGASHI
  • Patent number: 8969942
    Abstract: In a non-volatile semiconductor memory device and a method for manufacturing the device, each memory cell and its select Tr have the same gate insulating film as a Vcc Tr. Further, the gate electrodes of a Vpp Tr and Vcc Tr are realized by the use of a first polysilicon layer. A material such as salicide or a metal, which differs from second polysilicon (which forms a control gate layer), may be provided on the first polysilicon layer. With the above features, a non-volatile semiconductor memory device can be manufactured by reduced steps and be operated at high speed in a reliable manner.
    Type: Grant
    Filed: March 6, 2014
    Date of Patent: March 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshitake Yaegashi, Kazuhiro Shimizu, Seiichi Aritome
  • Publication number: 20140367766
    Abstract: A nonvolatile semiconductor storage device including a number of memory cells formed on a semiconductor substrate, each of the memory cells has a tunnel insulating film, a charge storage layer, a block insulating film, and a gate electrode which are formed in sequence on the substrate. The gate electrode is structured such that at least first and second gate electrode layers are stacked. The dimension in the direction of gate length of the second gate electrode layer, which is formed on the first gate electrode layer, is smaller than the dimension in the direction of gate length of the first gate electrode layer.
    Type: Application
    Filed: September 3, 2014
    Publication date: December 18, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Toshitake YAEGASHI
  • Patent number: 8878282
    Abstract: A nonvolatile semiconductor storage device including a number of memory cells formed on a semiconductor substrate, each of the memory cells has a tunnel insulating film, a charge storage layer, a block insulating film, and a gate electrode which are formed in sequence on the substrate. The gate electrode is structured such that at least first and second gate electrode layers are stacked. The dimension in the direction of gate length of the second gate electrode layer, which is formed on the first gate electrode layer, is smaller than the dimension in the direction of gate length of the first gate electrode layer.
    Type: Grant
    Filed: September 18, 2013
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshitake Yaegashi
  • Publication number: 20140217494
    Abstract: First and second memory cells have first and second channels, first and second tunnel insulating films, first and second charge storage layers formed of an insulating film, first and second block insulating films, and first and second gate electrodes. A first select transistor has a third channel, a first gate insulating film, and a first gate electrode. The first channel includes a first-conductivity-type region and a second-conductivity-type region which is formed on at least a part of the first-conductivity-type region and whose conductivity type is opposite to the first conductivity type. The third channel includes the first-conductivity-type region and the second-conductivity-type region formed on the first-conductivity-type region. The number of data stored in the first memory cell is smaller than that of data stored in the second memory cell.
    Type: Application
    Filed: April 15, 2014
    Publication date: August 7, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Toshitake YAEGASHI
  • Publication number: 20140183617
    Abstract: In a non-volatile semiconductor memory device and a method for manufacturing the device, each memory cell and its select Tr have the same gate insulating film as a Vcc Tr. Further, the gate electrodes of a Vpp Tr and Vcc Tr are realized by the use of a first polysilicon layer. A material such as salicide or a metal, which differs from second polysilicon (which forms a control gate layer), may be provided on the first polysilicon layer. With the above features, a non-volatile semiconductor memory device can be manufactured by reduced steps and be operated at high speed in a reliable manner.
    Type: Application
    Filed: March 6, 2014
    Publication date: July 3, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshitake Yaegashi, Kazuhiro Shimizu, Seiichi Aritome
  • Patent number: 8735966
    Abstract: First and second memory cells have first and second channels, first and second tunnel insulating films, first and second charge storage layers formed of an insulating film, first and second block insulating films, and first and second gate electrodes. A first select transistor has a third channel, a first gate insulating film, and a first gate electrode. The first channel includes a first-conductivity-type region and a second-conductivity-type region which is formed on at least a part of the first-conductivity-type region and whose conductivity type is opposite to the first conductivity type. The third channel includes the first-conductivity-type region and the second-conductivity-type region formed on the first-conductivity-type region. The number of data stored in the first memory cell is smaller than that of data stored in the second memory cell.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: May 27, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshitake Yaegashi
  • Patent number: 8728903
    Abstract: A first isolation is formed on a semiconductor substrate, and a first element region is isolated via the first isolation. A first gate insulating film is formed on the first element region, and a first gate electrode is formed on the first gate insulating film. A second isolation is formed on the semiconductor substrate, and a second element region is isolated via the second isolation. A second gate insulating film is formed on the second element region, and a second gate electrode is formed on the second gate insulating film. A first oxide film is formed between the first isolation and the first element region. A second oxide film is formed between the second isolation and the second element region. The first isolation has a width narrower than the second isolation, and the first oxide film has a thickness thinner than the second oxide film.
    Type: Grant
    Filed: August 7, 2012
    Date of Patent: May 20, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshitake Yaegashi, Junichi Shiozawa
  • Patent number: 8723246
    Abstract: A nonvolatile semiconductor memory according to examples of the present invention comprises a memory cell and a peripheral transistor. The memory cell has a first intergate insulating film having a multilayer structure and provided on a floating gate electrode and an isolation insulating layer. The peripheral transistor has a second intergate insulating film having a multilayer structure and provided on a first gate electrode and a second isolation insulating layer. The first and second intergate insulating films have the same structure, and a lowermost insulating layer of the first intergate insulating film on the first isolation insulating layer is thinner than a lowermost insulating layer of the second intergate insulating film on the second isolation insulating layer.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: May 13, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshitake Yaegashi
  • Patent number: 8698225
    Abstract: In a non-volatile semiconductor memory device and a method for manufacturing the device, each memory cell and its select Tr have the same gate insulating film as a Vcc Tr. Further, the gate electrodes of a Vpp Tr and Vcc Tr are realized by the use of a first polysilicon layer. A material such as salicide or a metal, which differs from second polysilicon (which forms a control gate layer), may be provided on the first polysilicon layer. With the above features, a non-volatile semiconductor memory device can be manufactured by reduced steps and be operated at high speed in a reliable manner.
    Type: Grant
    Filed: January 18, 2011
    Date of Patent: April 15, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshitake Yaegashi, Kazuhiro Shimizu, Seiichi Aritome
  • Patent number: 8679916
    Abstract: In device isolation trenches, a first device-isolation insulator film is formed to have recesses thereon and a second device-isolation insulator film is formed in the recesses. The uppermost portions at both ends of the first device-isolation insulator film are located higher than the uppermost portions at both ends of the second device-isolation insulator film.
    Type: Grant
    Filed: September 12, 2013
    Date of Patent: March 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshitake Yaegashi, Koki Ueno
  • Patent number: 8648405
    Abstract: A nonvolatile semiconductor memory device includes a plurality of floating gate electrodes respectively formed above a semiconductor substrate with first insulating films disposed therebetween, and a control gate electrode formed above the plurality of floating gate electrodes with a second insulating film disposed therebetween. In each of the plurality of floating gate electrodes is formed to have a width of an upper portion thereof in a channel width direction which is smaller than a width of a lower portion thereof in the channel width direction and one of contact surfaces thereof on at least opposed sides which contact the second insulating film is formed to have one surface, and the second insulating film has a maximum film thickness in a vertical direction, the maximum film thickness being set smaller than a distance from a lowest surface to a highest surface of the second insulating film in the vertical direction.
    Type: Grant
    Filed: October 4, 2012
    Date of Patent: February 11, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshitake Yaegashi
  • Patent number: 8647940
    Abstract: A semiconductor memory device includes a first select transistor, first stepped portion, and a first contact plug. The first select transistor is formed on a side of an upper surface of a substrate and has a first multi-layer gate. The first stepped portion is formed by etching the substrate adjacent to the first multi-layer gate of the first select transistor such that the first stepped portion forms a cavity in the upper surface of the substrate. The first contact plug is formed in the first stepped portion.
    Type: Grant
    Filed: August 9, 2013
    Date of Patent: February 11, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshitake Yaegashi
  • Patent number: 8637915
    Abstract: A nonvolatile semiconductor memory includes first and second memory cells having a floating gate and a control gate. The floating gate of the first and second memory cells is comprised a first part, and a second part arranged on the first part, and a width of the second part in an extending direction of the control gate is narrower than that of the first part. A first space between the first parts of the first and second memory cells is filled with one kind of an insulator. The control gate is arranged at a second space between the second parts of the first and second memory cells.
    Type: Grant
    Filed: January 14, 2011
    Date of Patent: January 28, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Ichige, Fumitaka Arai, Riichiro Shirota, Toshitake Yaegashi, Yoshio Ozawa, Akihito Yamamoto, Ichiro Mizushima, Yoshihiko Saito
  • Publication number: 20140017875
    Abstract: In device isolation trenches, a first device-isolation insulator film is formed to have recesses thereon and a second device-isolation insulator film is formed in the recesses. The uppermost portions at both ends of the first device-isolation insulator film are located higher than the uppermost portions at both ends of the second device-isolation insulator film.
    Type: Application
    Filed: September 12, 2013
    Publication date: January 16, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toshitake YAEGASHI, Koki Ueno