Patents by Inventor Reika Ichihara

Reika Ichihara 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: 20120112171
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a first stacked structure body, a first semiconductor layer, a first organic film, a first semiconductor-side insulating film, and a first electrode-side insulating film. The first stacked structure body includes a plurality of first electrode films stacked along a first direction and a first inter-electrode insulating film provided between the first electrode films. The first semiconductor layer is opposed to side faces of the first electrode films. The first organic film is provided between the side faces of the first electrode films and the first semiconductor layer and containing an organic compound. The first semiconductor-side insulating film is provided between the first organic film and the first semiconductor layer. The first electrode-side insulating film provided between the first organic film and the side faces of the first electrode films.
    Type: Application
    Filed: September 16, 2011
    Publication date: May 10, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shigeki Hattori, Reika Ichihara, Masaya Terai, Hideyuki Nishizawa, Tsukasa Tada, Koji Asakawa, Hiroyuki Fuke, Satoshi Mikoshiba, Yoshiaki Fukuzumi, Hideaki Aochi
  • Patent number: 8174080
    Abstract: A semiconductor device includes a semiconductor substrate, an nMISFET formed on the substrate, the nMISFET including a first dielectric formed on the substrate and a first metal gate electrode formed on the first dielectric and formed of one metal element selected from Ti, Zr, Hf, Ta, Sc, Y, a lanthanoide and actinide series and of one selected from boride, silicide and germanide compounds of the one metal element, and a pMISFET formed on the substrate, the pMISFET including a second dielectric formed on the substrate and a second metal gate electrode formed on the second dielectric and made of the same material as that of the first metal gate electrode, at least a portion of the second dielectric facing the second metal gate electrode being made of an insulating material different from that of at least a portion of the first dielectric facing the first metal gate electrode.
    Type: Grant
    Filed: July 15, 2011
    Date of Patent: May 8, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Reika Ichihara, Yoshinori Tsuchiya, Masato Koyama, Akira Nishiyama
  • Patent number: 8148787
    Abstract: There is disclosed a semiconductor device comprising a P-channel MIS transistor which includes an N-type semiconductor layer, a first gate insulating layer formed on the N-type semiconductor layer and containing a carbon compound of a metal, and an N-channel MIS transistor which includes a P-type semiconductor layer, a second gate insulating layer formed on the P-type semiconductor layer, and a second gate electrode formed on the second gate insulating layer.
    Type: Grant
    Filed: March 9, 2010
    Date of Patent: April 3, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masato Koyama, Akira Nishiyama, Yoshinori Tsuchiya, Reika Ichihara
  • Publication number: 20120063193
    Abstract: According to one embodiment, a multi-level resistance change memory includes a memory cell includes first and second resistance change films connected in series, and a capacitor connected in parallel to the first resistance change film, a voltage pulse generating circuit generating a first voltage pulse with a first pulse width to divide a voltage of the first voltage pulse into the first and second resistance change films based on a resistance ratio thereof, and generating a second voltage pulse with a second pulse width shorter than the first pulse width to apply a voltage of the second voltage pulse to the second resistance change film by a transient response of the capacitor, and a control circuit which is stored multi-level data to the memory cell by using the first and second voltage pulses in a writing.
    Type: Application
    Filed: March 22, 2011
    Publication date: March 15, 2012
    Inventor: Reika ICHIHARA
  • Patent number: 8129792
    Abstract: A semiconductor device includes n- and p-type semiconductor regions separately formed on a substrate, an interlayer insulator formed on the substrate and having first and second trenches formed to reach the n- and p-type regions. There are further included first and second gate insulators formed inside of the first and second trenches, a first metal layer formed inside of the first trench via the first gate insulator, a second metal layer formed in a thickness of 1 monolayer or more and 1.5 nm or less inside of the second trench via the second gate insulator, a third metal layer formed on the second metal layer and containing at least one of a simple substance, a nitride, a carbide and an oxide of at least one metal element of alkaline earth metal elements and group III elements, first and second source/drain regions formed on the n- and p-type regions.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: March 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Reika Ichihara, Yoshinori Tsuchiya, Hiroki Tanaka, Masahiko Yoshiki, Masato Koyama
  • Publication number: 20120049289
    Abstract: A semiconductor device includes pMISFET and nMIS formed on the semiconductor substrate. The pMISFET includes, on the semiconductor substrate, first source/drain regions, a first gate dielectric formed therebetween, first lower and upper metal layers stacked on the first gate dielectric, a first upper metal layer containing at least one metallic element belonging to groups IIA and IIIA. The nMISFET includes, on the semiconductor substrate, second source/drain regions, second gate dielectric formed therebetween, a second lower and upper metal layers stacked on the second gate dielectric and the second upper metal layer substantially having the same composition as the first upper metal layer. The first lower metal layer is thicker than the second lower metal layer, and the atomic density of the metallic element contained in the first gate dielectric is lower than the atomic density of the metallic element contained in the second gate dielectric.
    Type: Application
    Filed: November 7, 2011
    Publication date: March 1, 2012
    Inventors: Reika ICHIHARA, Masato Koyama
  • Publication number: 20120012807
    Abstract: A semiconductor memory device in an embodiment comprises memory cells, each of the memory cells disposed between a first line and a second line and having a variable resistance element and a switching element connected in series. The variable resistance element includes a variable resistance layer configured to change in resistance value thereof between a low-resistance state and a high-resistance state. The variable resistance layer is configured by a transition metal oxide. A ratio of transition metal and oxygen configuring the transition metal oxide varies between 1:1 and 1:2 along a first direction directed from the first line to the second line.
    Type: Application
    Filed: July 13, 2011
    Publication date: January 19, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takeshi YAMAGUCHI, Hirofumi Inoue, Reika Ichihara, Takayuki Tsukamoto, Takashi Shigeoka, Katsuyuki Sekine, Shinya Aoki
  • Patent number: 8085577
    Abstract: A nonvolatile semiconductor memory device comprises: a plurality of first lines; a plurality of second lines; a plurality of memory cells each disposed at each of crossing-points of the first lines and the second lines and each comprising a variable resistor and a bi-directional diode; and a voltage control circuit configured to control a voltage of selected one of the first lines, unselected ones of the first lines, selected one of the second lines, and unselected ones of the second lines, respectively. The variable resistor is configured to change its resistance value depending on a polarity of a voltage applied thereto. The voltage control circuit is configured to apply a voltage pulse to the selected one of the first lines and to connect a capacitor of a certain capacitance to one end of the selected one of the second lines.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: December 27, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Kanno, Reika Ichihara, Takayuki Tsukamoto, Kenichi Murooka
  • Patent number: 8076732
    Abstract: A semiconductor device includes pMISFET and nMIS formed on the semiconductor substrate. The pMISFET includes, on the semiconductor substrate, first source/drain regions, a first gate dielectric formed therebetween, first lower and upper metal layers stacked on the first gate dielectric, a first upper metal layer containing at least one metallic element belonging to groups IIA and IIIA. The nMISFET includes, on the semiconductor substrate, second source/drain regions, second gate dielectric formed therebetween, a second lower and upper metal layers stacked on the second gate dielectric and the second upper metal layer substantially having the same composition as the first upper metal layer. The first lower metal layer is thicker than the second lower metal layer, and the atomic density of the metallic element contained in the first gate dielectric is lower than the atomic density of the metallic element contained in the second gate dielectric.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: December 13, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Reika Ichihara, Masato Koyama
  • Publication number: 20110275184
    Abstract: A semiconductor device includes a semiconductor substrate, an nMISFET formed on the substrate, the nMISFET including a first dielectric formed on the substrate and a first metal gate electrode formed on the first dielectric and formed of one metal element selected from Ti, Zr, Hf, Ta, Sc, Y, a lanthanoide and actinide series and of one selected from boride, silicide and germanide compounds of the one metal element, and a pMISFET formed on the substrate, the pMISFET including a second dielectric formed on the substrate and a second metal gate electrode formed on the second dielectric and made of the same material as that of the first metal gate electrode, at least a portion of the second dielectric facing the second metal gate electrode being made of an insulating material different from that of at least a portion of the first dielectric facing the first metal gate electrode.
    Type: Application
    Filed: July 15, 2011
    Publication date: November 10, 2011
    Inventors: Reika ICHIHARA, Yoshinori TSUCHIYA, Masato KOYAMA, Akira NISHIYAMA
  • Patent number: 8053300
    Abstract: A semiconductor device includes a semiconductor substrate, an nMISFET formed on the substrate, the nMISFET including a first dielectric formed on the substrate and a first metal gate electrode formed on the first dielectric and formed of one metal element selected from Ti, Zr, Hf, Ta, Sc, Y, a lanthanoide and actinide series and of one selected from boride, silicide and germanide compounds of the one metal element, and a pMISFET formed on the substrate, the pMISFET including a second dielectric formed on the substrate and a second metal gate electrode formed on the second dielectric and made of the same material as that of the first metal gate electrode, at least a portion of the second dielectric facing the second metal gate electrode being made of an insulating material different from that of at least a portion of the first dielectric facing the first metal gate electrode.
    Type: Grant
    Filed: August 20, 2007
    Date of Patent: November 8, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Reika Ichihara, Yoshinori Tsuchiya, Masato Koyama, Akira Nishiyama
  • Publication number: 20110266632
    Abstract: A semiconductor device includes a semiconductor substrate, an nMISFET formed on the substrate, the nMISFET including a first dielectric formed on the substrate and a first metal gate electrode formed on the first dielectric and formed of one metal element selected from Ti, Zr, Hf, Ta, Sc, Y, a lanthanoide and actinide series and of one selected from boride, silicide and germanide compounds of the one metal element, and a pMISFET formed on the substrate, the pMISFET including a second dielectric formed on the substrate and a second metal gate electrode formed on the second dielectric and made of the same material as that of the first metal gate electrode, at least a portion of the second dielectric facing the second metal gate electrode being made of an insulating material different from that of at least a portion of the first dielectric facing the first metal gate electrode.
    Type: Application
    Filed: July 15, 2011
    Publication date: November 3, 2011
    Inventors: Reika ICHIHARA, Yoshinori Tsuchiya, Masato Koyama, Akira Nishiyama
  • Publication number: 20110216574
    Abstract: A nonvolatile semiconductor memory device in accordance with an embodiment comprises a plurality of first, second lines, a plurality of memory cells, and a control circuit. The plurality of second lines extend so as to intersect the first lines. The plurality of memory cells are disposed at intersections of the first, second lines, and each includes a variable resistor. The control circuit is configured to control a voltage applied to the memory cells. The control circuit applies a first pulse voltage to the variable resistor during a forming operation. In addition, the control circuit applies a second pulse voltage to the variable resistor during a setting operation, the second pulse voltage having a polarity opposite to the first pulse voltage. Furthermore, the control circuit applies a third pulse voltage to the variable resistor during a resetting operation, the third pulse voltage having a polarity identical to the first pulse voltage.
    Type: Application
    Filed: September 21, 2010
    Publication date: September 8, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Reika ICHIHARA, Takayuki Tsukamoto
  • Patent number: 7986014
    Abstract: A semiconductor device includes a semiconductor substrate, an nMISFET formed on the substrate, the nMISFET including a first dielectric formed on the substrate and a first metal gate electrode formed on the first dielectric and formed of one metal element selected from Ti, Zr, Hf, Ta, Sc, Y, a lanthanoide and actinide series and of one selected from boride, silicide and germanide compounds of the one metal element, and a pMISFET formed on the substrate, the pMISFET including a second dielectric formed on the substrate and a second metal gate electrode formed on the second dielectric and made of the same material as that of the first metal gate electrode, at least a portion of the second dielectric facing the second metal gate electrode being made of an insulating material different from that of at least a portion of the first dielectric facing the first metal gate electrode.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: July 26, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Reika Ichihara, Yoshinori Tsuchiya, Masato Koyama, Akira Nishiyama
  • Patent number: 7968956
    Abstract: A semiconductor device includes a semiconductor substrate, a p-channel MIS transistor formed on the substrate, the p-channel transistor having a first gate dielectric formed on the substrate and a first gate electrode layer formed on the first dielectric, and an n-channel MIS transistor formed on the substrate, the n-channel transistor having a second gate dielectric formed on the substrate and a second gate electrode layer formed on the second dielectric. A bottom layer of the first gate electrode layer in contact with the first gate dielectric and a bottom layer of the second gate electrode layer in contact with the second gate dielectric have the same orientation and the same composition including Ta and C, and a mole ratio of Ta to a total of C and Ta, (Ta/(Ta+C)), is larger than 0.5.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: June 28, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kosuke Tatsumura, Masakazu Goto, Reika Ichihara, Masato Koyama, Shigeru Kawanaka, Kazuaki Nakajima
  • Patent number: 7964489
    Abstract: A semiconductor device includes: a p-channel MIS transistor including: a first insulating layer formed on a semiconductor region between a source region and a drain region, and containing at least silicon and oxygen; a second insulating layer formed on the first insulating layer, and containing hafnium, silicon, oxygen, and nitrogen, and a first gate electrode formed on the second insulating layer. The first and second insulating layers have a first and second region respectively. The first and second regions are in a 0.3 nm range in the film thickness direction from an interface between the first insulating layer and the second insulating layer. Each of the first and second regions include aluminum atoms with a concentration of 1×1020 cm?3 or more to 1×1022 cm?3 or less.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: June 21, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masato Koyama, Yoshinori Tsuchiya, Yuuichi Kamimuta, Reika Ichihara, Katsuyuki Sekine
  • Patent number: 7948790
    Abstract: A memory cell arranged between first and second wirings includes a variable-resistor element. A controller controls a voltage applied between the first and second wirings. The controller performs a first operation that applies a first voltage between the first and second wirings to switch the variable-resistor element from a first state with a resistance value not less than a first resistance value, to a second state with a resistance value not more than a second resistance value smaller than the first resistance value. The second operation applies a second voltage smaller than the first voltage between the first and second wirings to switch the variable-resistor element from the second state to the first state. In the first operation, a verify voltage is applied between the first and second wirings. Based on the obtained signal, a third voltage smaller than the first voltage is applied between the first and second wirings.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: May 24, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Tsukamoto, Reika Ichihara
  • Publication number: 20110103128
    Abstract: Nonvolatile semiconductor memory device of an embodiment includes: a memory cell array including a plurality of first and second lines intersecting each other and plural memory cells provided at intersections of the first and second lines and having data written and erased upon application of voltages of the same polarity; and a writing circuit configured to select first and second lines and supply a set or reset pulse to the memory cell through the selected first and second lines. In an erase operation, the writing circuit repeatedly supplies the reset pulse to a selected memory cell until data is erased, by increasing or decreasing voltage level and voltage application time of the reset pulse within a reset region. The reset region, or an aggregate of combinations of voltage level and voltage application time of the reset pulse, is a region where voltage level and voltage application time are negatively correlated.
    Type: Application
    Filed: September 15, 2010
    Publication date: May 5, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Kanno, Reika Ichihara, Takayuki Tsukamoto, Kenichi Murooka, Hirofumi Inoue
  • Publication number: 20110069532
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit. The memory cell array includes a plurality of first wirings, a plurality of second wirings intersecting the plurality of first wirings, and a plurality of memory cells provided at the intersections of the plurality of first and second wirings and each including a non-ohmic element and a variable resistance element connected in series. The control circuit selects one of the plurality of memory cells, generates an erasing pulse for erasing data from the selected memory cell, and supplies the erasing pulse to the selected memory cell. The control circuit executes data erase by applying a voltage of the erasing pulse to the non-ohmic element in the reverse bias direction.
    Type: Application
    Filed: September 7, 2010
    Publication date: March 24, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Reika ICHIHARA, Takayuki Tsukamoto, Hiroshi Kanno, Kenichi Murooka
  • Publication number: 20110032745
    Abstract: A non-volatile semiconductor memory device according to an aspect of embodiments of the present invention includes a memory cell array including: multiple first wirings; multiple second wirings crossing the multiple first wirings; and multiple electrically rewritable memory cells respectively arranged at intersections of the first wirings and the second wirings, and each formed of a variable resistor which stores a resistance value as data in a non-volatile manner. The non-volatile semiconductor memory device according to an aspect of the embodiments of the present invention further includes a controller for selecting a given one of the memory cells, generating an erase pulse which is used for erasing data, and supplying the erase pulse to the selected memory cell. The erase pulse has a pulse width which is increased or decreased exponentially in accordance with an access path length to the selected memory cell.
    Type: Application
    Filed: July 29, 2010
    Publication date: February 10, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Reika ICHIHARA, Takayuki Tsukamoto, Kenichi Murooka, Hirofumi Inoue, Hiroshi Kanno