Patents by Inventor Iwao Kunishima
Iwao Kunishima 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).
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Publication number: 20210202839Abstract: [Problem]: The problem of the present invention is to provide a stacked structure excellent in stability of atomic arrangement, a method of manufacturing same, and a semiconductor device using the stacked structure. [Solution]: The stacked structure of the present invention is characterized in that it has an alloy layer A having germanium and tellurium as a main component and an alloy layer B having tellurium and either of antimony or bismuth as a main component, and at least either of the alloy layer A or the alloy layer B contains at least either of sulfur or selenium as a chalcogen atom.Type: ApplicationFiled: June 21, 2019Publication date: July 1, 2021Inventors: Junji Tominaga, Noriyuki Miyata, Yoshiki Kamata, Iwao Kunishima
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Patent number: 10559750Abstract: According to one embodiment, a nonvolatile memory device includes a first conductive portion, an insulating film surrounding a side surface of the first conductive portion, an intermediate layer provided on the first conductive portion and the insulating film, a first film including a first portion provided on the intermediate layer and at least one second portion provided in the intermediate layer and outside an upper edge of the first conductive portion, the first film including, above the first conductive portion, a resistance change portion that has a first resistance state and a second resistance state having resistance higher than resistance in the first resistance state, and a second conductive portion provided at least on the resistance change portion.Type: GrantFiled: August 31, 2018Date of Patent: February 11, 2020Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yoshiaki Asao, Misako Morota, Yoshiki Kamata, Yukihiro Nomura, Iwao Kunishima
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Publication number: 20190288193Abstract: According to one embodiment, a nonvolatile memory device includes a first conductive portion, an insulating film surrounding a side surface of the first conductive portion, an intermediate layer provided on the first conductive portion and the insulating film, a first film including a first portion provided on the intermediate layer and at least one second portion provided in the intermediate layer and outside an upper edge of the first conductive portion, the first film including, above the first conductive portion, a resistance change portion that has a first resistance state and a second resistance state having resistance higher than resistance in the first resistance state, and a second conductive portion provided at least on the resistance change portion.Type: ApplicationFiled: August 31, 2018Publication date: September 19, 2019Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoshiaki ASAO, Misako MOROTA, Yoshiki KAMATA, Yukihiro NOMURA, Iwao KUNISHIMA
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Patent number: 10153429Abstract: A memory device according to an embodiment includes a first conductive layer, a second conductive layer, a third conductive layer intersecting the first conductive layer and the second conductive layer, and a resistance change layer including a first region which is provided between the first conductive layer and the third conductive layer and has a superlattice structure, a second region which is provided between the second conductive layer and the third conductive layer and has the superlattice structure, and a third region which is provided between the first region and the second region. The third region includes at least one element selected from the group consisting of O, F, C, P, B, N, H, Bi, Cd, Zn, Ga, Se, Al, S, Be, In, and Pb. Concentration of the at least one element in the third region is higher than that in the first region and the second region.Type: GrantFiled: June 28, 2017Date of Patent: December 11, 2018Assignee: Toshiba Memory CorporationInventors: Yoshiki Kamata, Yoshiaki Asao, Iwao Kunishima, Misako Morota
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Publication number: 20180006216Abstract: A memory device according to an embodiment includes a first conductive layer, a second conductive layer, a third conductive layer intersecting the first conductive layer and the second conductive layer, and a resistance change layer including a first region which is provided between the first conductive layer and the third conductive layer and has a superlattice structure, a second region which is provided between the second conductive layer and the third conductive layer and has the superlattice structure, and a third region which is provided between the first region and the second region. The third region includes at least one element selected from the group consisting of O, F, C, P, B, N, H, Bi, Cd, Zn, Ga, Se, Al, S, Be, In, and Pb. Concentration of the at least one element in the third region is higher than that in the first region and the second region.Type: ApplicationFiled: June 28, 2017Publication date: January 4, 2018Inventors: Yoshiki KAMATA, Yoshiaki ASAO, Iwao KUNISHIMA, Misako MOROTA
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Patent number: 9384829Abstract: A memory device includes n (n being an integer of 2 or more) resistance change films being series connected to each other. Each of the resistance change films is a superlattice film in which plural pairs of a first crystal layer made of a first compound and a second crystal layer made of a second compound are alternately stacked. An average composition of the entire resistance change film or an arrangement pitch of the first crystal layers and the second crystal layers are mutually different among the n resistance change films.Type: GrantFiled: March 20, 2013Date of Patent: July 5, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Hironobu Furuhashi, Iwao Kunishima, Susumu Shuto, Yoshiaki Asao, Gaku Sudo
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Patent number: 9324406Abstract: According to one embodiment, a semiconductor memory device includes a memory cell and a control circuit. The memory cell is such that a ferroelectric film is provided as a gate dielectric film. When data is stored in the memory cell, the control circuit applies a first voltage to the gate dielectric film and thereafter applies a second voltage, whose amplitude is smaller than that of the first voltage and whose polarity is opposite to that of the first voltage.Type: GrantFiled: January 8, 2015Date of Patent: April 26, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Susumu Shuto, Takayuki Okada, Iwao Kunishima
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Publication number: 20150117085Abstract: According to one embodiment, a semiconductor memory device includes a memory cell and a control circuit. The memory cell is such that a ferroelectric film is provided as a gate dielectric film. When data is stored in the memory cell, the control circuit applies a first voltage to the gate dielectric film and thereafter applies a second voltage, whose amplitude is smaller than that of the first voltage and whose polarity is opposite to that of the first voltage.Type: ApplicationFiled: January 8, 2015Publication date: April 30, 2015Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Susumu SHUTO, Takayuki OKADA, Iwao KUNISHIMA
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Patent number: 8953359Abstract: According to one embodiment, a semiconductor memory device includes a memory cell and a control circuit. The memory cell is such that a ferroelectric film is provided as a gate dielectric film. When data is stored in the memory cell, the control circuit applies a first voltage to the gate dielectric film and thereafter applies a second voltage, whose amplitude is smaller than that of the first voltage and whose polarity is opposite to that of the first voltage.Type: GrantFiled: July 26, 2013Date of Patent: February 10, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Susumu Shuto, Takayuki Okada, Iwao Kunishima
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Publication number: 20140254274Abstract: According to one embodiment, a semiconductor memory device includes a memory cell and a control circuit. The memory cell is such that a ferroelectric film is provided as a gate dielectric film. When data is stored in the memory cell, the control circuit applies a first voltage to the gate dielectric film and thereafter applies a second voltage, whose amplitude is smaller than that of the first voltage and whose polarity is opposite to that of the first voltage.Type: ApplicationFiled: July 26, 2013Publication date: September 11, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Susumu SHUTO, Takayuki OKADA, Iwao KUNISHIMA
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Publication number: 20140185359Abstract: According to one embodiment, a memory device includes n (n being an integer of 2 or more) resistance change films being series connected to each other. Each of the resistance change films is a superlattice film in which a plurality of pairs of a first crystal layer made of a first compound and a second crystal layer made of a second compound are alternately stacked. Average composition of the entire resistance change film or arrangement pitch of the first crystal layers and the second crystal layers are mutually different among the n resistance change films.Type: ApplicationFiled: March 20, 2013Publication date: July 3, 2014Inventors: Hironobu FURUHASHI, Iwao KUNISHIMA, Susumu SHUTO, Yoshiaki ASAO, Gaku SUDO
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Publication number: 20110140238Abstract: According to an embodiment, there is provided a method for manufacturing a semiconductor device having a ferroelectric capacitor including a lower electrode, an upper electrode, and a dielectric film provided between the lower electrode and the upper electrode. The method includes firstly forming a conductive film on the lower electrode. Next, it includes forming an SRO film on the conductive film. Then, it includes performing a first thermal treatment crystallizing the SRO film. Then, it includes forming a first PZT film on the SRO film by the sputtering method and performing a second thermal treatment crystallizing the first PZT film. Then, it includes forming the second PZT film on the first PZT film by the CVD method.Type: ApplicationFiled: September 21, 2010Publication date: June 16, 2011Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Katsuaki NATORI, Koji YAMAKAWA, Takayuki OKADA, Iwao KUNISHIMA, Hiroshi NAKAKI
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Patent number: 7763920Abstract: According to an aspect of the present invention, there is provided a semiconductor memory including a lower electrode, a first insulating region formed in the same layer as the lower electrode, a ferroelectric film formed on the lower electrode and on the first insulating region, an upper electrode formed on the ferroelectric film, a second insulating region formed in the same layer as the upper electrode and a transistor. The first insulating region partitions the lower electrode. The second insulating region partitions the upper electrode. The transistor includes a first impurity region connected to the lower electrode and a second impurity region connected to the upper electrode. At least one of the first insulating region and the second insulating region is formed by insulating the lower electrode or the upper electrode.Type: GrantFiled: September 11, 2007Date of Patent: July 27, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Yoshinori Kumura, Tohru Ozaki, Iwao Kunishima
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Publication number: 20100012994Abstract: A semiconductor storage device has the ferroelectric capacitor has: a capacitor film formed above the MOS transistor with an interlayer insulating film interposed therebetween; a first capacitor electrode electrically connected to a source region of the MOS transistor and formed in contact with one side wall of the capacitor film; and a second capacitor electrode electrically connected to a drain region of the MOS transistor and formed in contact with the other side wall of the capacitor film, and the capacitor film is composed of a film stack including a plurality of films including a first insulating film intended to orient a film formed on an upper surface thereof in a predetermined direction and a ferroelectric film formed on the first insulating film to be oriented in a direction perpendicular to the semiconductor substrate.Type: ApplicationFiled: July 16, 2009Publication date: January 21, 2010Applicant: Kabushiki Kaisha ToshibaInventors: Tohru OZAKI, Iwao KUNISHIMA, Yoshinori KUMURA
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Patent number: 7612398Abstract: A semiconductor storage device wherein a plurality of ferroelectric capacitors are sufficiently covered with a hydrogen barrier film formed thereon comprises a field effect transistor formed on one surface side of a semiconductor substrate, a plurality of ferroelectric capacitors formed close to each other above the field effect transistor, an insulting film configured to cover the plurality of ferroelectric capacitors and planarised a space between adjacent ferroelectric capacitors in a self-aligned manner during formation thereof, and a hydrogen barrier film formed on the insulating film.Type: GrantFiled: September 1, 2004Date of Patent: November 3, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Yoshinori Kumura, Yoshiro Shimojo, Iwao Kunishima, Tohru Ozaki
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Patent number: 7573084Abstract: According to an aspect of the present invention, there is provided a non-volatile semiconductor memory device, including a ferroelectric capacitor being stacked a first electrode, a ferroelectric film and a second electrode in order, a first protective film with hydrogen barrier performance, the first protective film being formed under the first electrode and on a side-wall of the ferroelectric capacitor, the first protective film being widened from the second electrode towards the first electrode, a second protective film with hydrogen barrier performance, the second protective film being formed over the second electrode and on the first protective film formed on the side-wall of the ferroelectric capacitor, the second protective film being widened from the first electrode towards the second electrode, a cell transistor, a source of the cell transistor being connected to the first electrode, a drain of the cell transistor being connected to a bit line and a gate being connected to a word line.Type: GrantFiled: September 18, 2007Date of Patent: August 11, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Yoshinori Kumura, Tohru Ozaki, Iwao Kunishima
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Patent number: 7446362Abstract: A semiconductor memory device includes a semiconductor substrate having a first region and a second region, a transistor placed in the first region of the semiconductor substrate, a first insulating film formed on the semiconductor substrate in the first and second regions and on the transistor, a first ferroelectric capacitor formed on the first insulating film in the first region and electrically connected to the transistor, a hydrogen barrier film formed above the first ferroelectric capacitor and above the first insulating film in the first and second regions, a first contact penetrating the hydrogen barrier film in the first region and electrically connected to the first ferroelectric capacitor, and a second contact which penetrates the hydrogen barrier film in the second region and which is in a floating state.Type: GrantFiled: November 16, 2007Date of Patent: November 4, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Osamu Hidaka, Iwao Kunishima, Hiroyuki Kanaya
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Patent number: 7429508Abstract: A semiconductor memory device includes a semiconductor substrate having a first region and a second region, a transistor placed in the first region of the semiconductor substrate, a first insulating film formed on the semiconductor substrate in the first and second regions and on the transistor, a first ferroelectric capacitor formed on the first insulating film in the first region and electrically connected to the transistor, a hydrogen barrier film formed above the first ferroelectric capacitor and above the first insulating film in the first and second regions, a first contact penetrating the hydrogen barrier film in the first region and electrically connected to the first ferroelectric capacitor, and a second contact which penetrates the hydrogen barrier film in the second region and which is in a floating state.Type: GrantFiled: November 16, 2007Date of Patent: September 30, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Osamu Hidaka, Iwao Kunishima, Hiroyuki Kanaya
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Publication number: 20080230818Abstract: According to an aspect of the present invention, there is provided a non-volatile memory including: a transistor formed on a semiconductor substrate, the transistor including: two diffusion layers and a gate therebetween; a first insulating film formed on a top and a side surfaces of the gate; a first and a second contact plugs formed on corresponding one of the diffusion layers to contact the first insulating film; a ferroelectric capacitor formed on the first contact plug and on the first insulating film, the ferroelectric capacitor including: a first and a second electrodes and a ferroelectric film therebetween; a third contact plug formed on the second electrode; and a fourth contact plug formed on the second contact plug.Type: ApplicationFiled: March 21, 2008Publication date: September 25, 2008Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoshinori Kumura, Tohru Ozaki, Iwao Kunishima
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Publication number: 20080173912Abstract: A semiconductor device comprising a ferroelectric capacitor having improved reliability is disclosed. According to one aspect of the present invention, it is provided a semiconductor device comprising a transistor formed on a semiconductor substrate, a ferroelectric capacitor formed above the transistor and comprising a lower electrode, a ferroelectric film and an upper electrode, a first hydrogen barrier film formed over the ferroelectric capacitor, an insulator formed over the first hydrogen barrier film, a contact plug disposed in the insulator and electrically connected with the upper electrode, a second hydrogen barrier film disposed between the contact plug and the insulator continuously, and a wiring connected with the contact plug.Type: ApplicationFiled: November 16, 2007Publication date: July 24, 2008Inventors: Yoshinori KUMURA, Tohru Ozaki, Susumu Shuto, Yoshiro Shimojo, Iwao Kunishima