Patents by Inventor Takashi Izumida

Takashi Izumida 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: 8610282
    Abstract: In one embodiment, a semiconductor device includes a substrate, and a plurality of interconnects provided in the same interconnect layer above the substrate. The device further includes a plurality of insulators provided so as to be buried between the plurality of interconnects. Moreover, the plurality of interconnects include an interconnect group in which 2N or more interconnects are successively arrayed so that correlation coefficients of line edge roughness (LER) between both side surfaces of the respective interconnects are positive, where N is an integer of 4 or more.
    Type: Grant
    Filed: May 17, 2011
    Date of Patent: December 17, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Kurusu, Takashi Izumida, Hiroyoshi Tanimoto, Nobutoshi Aoki
  • Patent number: 8598649
    Abstract: A nonvolatile semiconductor memory device according to embodiment includes: a semiconductor substrate having an upper portion being partitioned into a plurality of semiconductor portions extending in a first direction; a charge storage film provided on the semiconductor portion; a word-line electrode provided on the semiconductor substrate and extending in a second direction intersecting with the first direction; and a pair of selection gate electrodes provided on both sides of the word-line electrode in the first direction on the semiconductor substrate and extending in the second direction, a shortest distance between a corner portion of each of the semiconductor portions and each of the selection gate electrodes being longer than a shortest distance between the corner portion of the semiconductor portion and the word-line electrode in a cross section parallel to the second direction.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: December 3, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Okamura, Noboru Ooike, Wataru Sakamoto, Takashi Izumida
  • Patent number: 8575684
    Abstract: In a nonvolatile semiconductor memory device provided with memory cell transistors arranged in a direction and a select transistor to select the memory cell transistors, each of the memory cell transistors of a charge trap type are at least composed of a first insulating layer and a first gate electrode respectively, and the select transistor is at least composed of a second insulating layer and a second gate electrode. The first gate electrode is provided with a first silicide layer of a first width formed on the first insulating layer. The second gate electrode is provided with an impurity-doped silicon layer formed on the second insulating layer and with a second silicide layer of a second width formed on the impurity-doped silicon layer. The second silicide has the same composition as the first silicide. The second width is larger than the first width.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: November 5, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Nobutoshi Aoki
  • Publication number: 20130250670
    Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic layer, a second magnetic layer, a non-magnetic layer formed between the first magnetic layer and the second magnetic layer, a charge storage layer having a first surface and a second surface different from the first surface, the first surface facing the second magnetic layer, a first insulating layer formed between the second magnetic layer and the first surface of the charge storage layer, and a second insulating layer formed on the second surface of the charge storage layer.
    Type: Application
    Filed: February 28, 2013
    Publication date: September 26, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tsukasa NAKAI, Takashi IZUMIDA, Jyunichi OZEKI, Masaki KONDO, Toshiyuki ENDA, Nobutoshi AOKI
  • Publication number: 20130248965
    Abstract: According to one embodiment, there is provided a nonvolatile semiconductor memory device including a substrate, a laminated film which has a configuration where first insulating layers and first electrode layers are alternately laminated in a first direction vertical to the substrate, a second insulating layer formed on an inner wall of a first through hole pierced in the first insulating layers and the first electrode layers along the first direction, an intermediate layer formed on a surface of the second insulating layer, a third insulating layer formed on a surface of the intermediate layer, and a pillar-like first semiconductor region which is formed on a surface of the third insulating layer and extends along the first direction.
    Type: Application
    Filed: March 20, 2013
    Publication date: September 26, 2013
    Inventors: Tsukasa NAKAI, Nobutoshi AOKI, Takashi IZUMIDA, Masaki KONDO, Toshiyuki ENDA
  • Publication number: 20130240970
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a semiconductor substrate, a gate insulating film formed on the semiconductor substrate, a floating gate electrode formed on the gate insulating film, made of polysilicon containing a p-type impurity as a group XIII element, and having a lower film and an upper film stacked on the lower film, an inter-electrode insulating film formed on the floating gate electrode, and a control gate electrode formed on the inter-electrode insulating film. One of a concentration and an activation concentration of the p-type impurity in the upper film is higher than one of a concentration and an activation concentration of the p-type impurity in the lower film.
    Type: Application
    Filed: September 4, 2012
    Publication date: September 19, 2013
    Inventors: Masaki KONDO, Nobutoshi AOKI, Takashi IZUMIDA, Tomomi YODA
  • Patent number: 8487364
    Abstract: A nonvolatile semiconductor memory device according to embodiment includes: a semiconductor substrate having an upper portion being partitioned into a plurality of semiconductor portions extending in a first direction; a charge storage film provided on the semiconductor portion; a word-line electrode provided on the semiconductor substrate and extending in a second direction intersecting with the first direction; and a pair of selection gate electrodes provided on both sides of the word-line electrode in the first direction on the semiconductor substrate and extending in the second direction, a shortest distance between a corner portion of each of the semiconductor portions and each of the selection gate electrodes being longer than a shortest distance between the corner portion of the semiconductor portion and the word-line electrode in a cross section parallel to the second direction.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: July 16, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Okamura, Noboru Ooike, Wataru Sakamoto, Takashi Izumida
  • Patent number: 8420467
    Abstract: A semiconductor device has a semiconductor substrate, a semiconductor fin which is formed on the semiconductor substrate, which has a long side direction and a short side direction, and which has a carbon-containing silicon film including an impurity and a silicon film formed on the carbon-containing silicon film, a gate electrode which is formed to face both side surfaces of the semiconductor fin in the short side direction, source and drain regions which are respectively formed in the semiconductor fin located in the direction of both sides in the long side direction of the semiconductor fin so as to sandwich the gate electrode, and an element isolation insulating film which is formed on the side surface of the semiconductor fin and between the gate electrode and the semiconductor substrate.
    Type: Grant
    Filed: September 2, 2011
    Date of Patent: April 16, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Nobutoshi Aoki
  • Publication number: 20130069148
    Abstract: According to one embodiment, a semiconductor device includes an element region partitioned by an isolation region in a semiconductor substrate, and a source region and a drain region formed in a surface layer of the element region by being isolated by a gate trench along a predetermined direction across the element region. The semiconductor device includes a gate electrode formed to reach a position deeper than the source region and the drain region by embedding at least part thereof in the gate trench with a gate dielectric film interposed therebetween. An interface in the drain region, which is in contact with the gate dielectric film, includes a projection projecting toward the gate electrode side.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 21, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takashi IZUMIDA, Nobutoshi AOKI
  • Publication number: 20130015500
    Abstract: According to one embodiment, a semiconductor device includes a semiconductor protrusion formed on a semiconductor substrate, a source/drain layer provided in a vertical direction of the semiconductor protrusion, a gate electrode provided on a side surface of the semiconductor protrusion through a gate insulating film, and a channel region provided on the side surface of the semiconductor protrusion. The potential height in the channel region is different between the drain layer side and the source layer side.
    Type: Application
    Filed: March 2, 2012
    Publication date: January 17, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takashi IZUMIDA, Toshitaka MIYATA
  • Patent number: 8354706
    Abstract: A semiconductor memory device according to an embodiment of the present invention includes a substrate, a first gate insulator formed on the substrate and serving as an F-N (Fowler-Nordheim) tunneling film, a first floating gate formed on the first gate insulator, a second gate insulator formed on the first floating gate and serving as an F-N tunneling film, a second floating gate formed on the second gate insulator, an intergate insulator formed on the second floating gate and serving as a charge blocking film, and a control gate formed on the intergate insulator, at least one of the first and second floating gates including a metal layer.
    Type: Grant
    Filed: March 8, 2010
    Date of Patent: January 15, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takahisa Kanemura, Tomomi Kusaka, Takashi Izumida, Masaki Kondo, Nobutoshi Aoki
  • Patent number: 8289782
    Abstract: A semiconductor memory device according to an embodiment of the present invention includes a substrate, a gate insulator formed on the substrate and serving as an F-N (Fowler-Nordheim) tunneling film, a first floating gate formed on the gate insulator, a first intergate insulator formed on the first floating gate and serving as an F-N tunneling film, a second floating gate formed on the first intergate insulator, a second intergate insulator formed on the second floating gate and serving as a charge blocking film, and a control gate formed on the second intergate insulator.
    Type: Grant
    Filed: March 8, 2010
    Date of Patent: October 16, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Tomomi Kusaka, Masaki Kondo, Nobutoshi Aoki
  • Patent number: 8258562
    Abstract: A semiconductor device of an example of the invention comprises a memory cell and a select gate transistor provided for the memory cell. A gate electrode of the select gate transistor has a Tri-gate structure in which an upper surface of a gate insulating film formed above a channel of the select gate transistor is set higher than a portion of an upper surface of an element isolation region of the select gate transistor.
    Type: Grant
    Filed: May 21, 2009
    Date of Patent: September 4, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Takahisa Kanemura, Nobutoshi Aoki
  • Patent number: 8212306
    Abstract: A semiconductor storage device has a semiconductor substrate, a plurality of first insulating films formed on the semiconductor substrate with predetermined spacing therebetween, an element isolation region formed between the first insulating films in a first direction, a floating gate electrode comprising a first charge accumulation film formed on the first insulating film, a second charge accumulation film formed on the first charge accumulation film and having a width in a second direction orthogonal to the first direction smaller than the width of the first charge accumulation film, and a third charge accumulation film formed on the second charge accumulation film and having the width in the second direction larger than the width of the second charge accumulation film, a second insulating film formed on the second charge accumulation film and between the second charge accumulation film and the element isolation region, a third insulating film formed on the charge accumulation film and the element isolatio
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: July 3, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Nobutoshi Aoki, Masaki Kondo, Takahisa Kanemura
  • Publication number: 20120146128
    Abstract: In a nonvolatile semiconductor memory device provided with memory cell transistors arranged in a direction and a select transistor to select the memory cell transistors, each of the memory cell transistors of a charge trap type are at least composed of a first insulating layer and a first gate electrode respectively, and the select transistor is at least composed of a second insulating layer and a second gate electrode. The first gate electrode is provided with a first silicide layer of a first width formed on the first insulating layer. The second gate electrode is provided with an impurity-doped silicon layer formed on the second insulating layer and with a second silicide layer of a second width formed on the impurity-doped silicon layer. The second silicide has the same composition as the first silicide. The second width is larger than the first width.
    Type: Application
    Filed: February 2, 2012
    Publication date: June 14, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takashi Izumida, Nobutoshi Aoki
  • Publication number: 20120139031
    Abstract: In a nonvolatile semiconductor memory device provided with memory cell transistors arranged in a direction and a select transistor to select the memory cell transistors, each of the memory cell transistors of a charge trap type are at least composed of a first insulating layer and a first gate electrode respectively, and the select transistor is at least composed of a second insulating layer and a second gate electrode. The first gate electrode is provided with a first silicide layer of a first width formed on the first insulating layer. The second gate electrode is provided with an impurity-doped silicon layer formed on the second insulating layer and with a second silicide layer of a second width formed on the impurity-doped silicon layer. The second silicide has the same composition as the first silicide. The second width is larger than the first width.
    Type: Application
    Filed: February 2, 2012
    Publication date: June 7, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takashi IZUMIDA, Nobutoshi AOKI
  • Patent number: 8148217
    Abstract: A method of manufacturing a semiconductor device includes forming a mask layer on a first-conductivity-type semiconductor substrate, etching the semiconductor substrate using the mask layer as a mask, thereby forming a projecting semiconductor layer, forming a first insulating layer on the semiconductor substrate to cover a lower portion of the projecting semiconductor layer, doping a first-conductivity-type impurity into the first insulating layer, thereby forming a high-impurity-concentration layer in the lower portion of the projecting semiconductor layer, forming gate insulating films on side surfaces of the projecting semiconductor layer which upwardly extend from an upper surface of the first insulating layer, and forming a gate electrode on the gate insulating films and on the first insulating film.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: April 3, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Sanae Ito, Takahisa Kanemura
  • Patent number: 8134203
    Abstract: In a nonvolatile semiconductor memory device provided with memory cell transistors arranged in a direction and a select transistor to select the memory cell transistors, each of the memory cell transistors of a charge trap type are at least composed of a first insulating layer and a first gate electrode respectively, and the select transistor is at least composed of a second insulating layer and a second gate electrode. The first gate electrode is provided with a first silicide layer of a first width formed on the first insulating layer. The second gate electrode is provided with an impurity-doped silicon layer formed on the second insulating layer and with a second silicide layer of a second width formed on the impurity-doped silicon layer. The second silicide has the same composition as the first silicide. The second width is larger than the first width.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: March 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Nobutoshi Aoki
  • Patent number: 8110864
    Abstract: In one aspect of the present invention, a nonvolatile semiconductor memory device may include a semiconductor substrate; a plurality of tunnel insulating films formed on the semiconductor substrate at predetermined intervals in a first direction; a plurality of floating gate electrodes each having a first portion and a second portion, the first portions being formed on the respective tunnel insulating films, the second portions being formed on the respective first portions and having smaller width than the first portions in the first direction; an inter-gate insulating film formed on the floating gate electrodes; and first and second control gate electrodes respectively formed on sidewalls, in the first direction, of the second portion of each of the plurality of floating gate electrodes with the inter-gate insulating film interposed therebetween.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: February 7, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Masaki Kondo
  • Publication number: 20120003801
    Abstract: A semiconductor device has a semiconductor substrate, a semiconductor fin which is formed on the semiconductor substrate, which has a long side direction and a short side direction, and which has a carbon-containing silicon film including an impurity and a silicon film formed on the carbon-containing silicon film, a gate electrode which is formed to face both side surfaces of the semiconductor fin in the short side direction, source and drain regions which are respectively formed in the semiconductor fin located in the direction of both sides in the long side direction of the semiconductor fin so as to sandwich the gate electrode, and an element isolation insulating film which is formed on the side surface of the semiconductor fin and between the gate electrode and the semiconductor substrate.
    Type: Application
    Filed: September 2, 2011
    Publication date: January 5, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takashi Izumida, Nobutoshi Aoki