Patents by Inventor Hiroyuki Fukumizu
Hiroyuki Fukumizu 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: 20140048761Abstract: A semiconductor memory device according to an embodiment comprises: a semiconductor substrate; and a memory cell block formed on the semiconductor substrate and configured having a plurality of memory cell arrays, each of the memory cell arrays including a plurality of column lines, a plurality of row lines, and a plurality of memory cells disposed at each of intersections of the plurality of column lines and the plurality of row lines, each of the memory cells including a variable resistance element having a transition metal oxide as a material, at least one of the plurality of column lines and the plurality of row lines being a polysilicon wiring line having polysilicon as a material, and the memory cell block including a block film between the variable resistance element of the memory cell and the polysilicon wiring line.Type: ApplicationFiled: December 28, 2012Publication date: February 20, 2014Inventors: Yasuhiro NOJIRI, Hiroyuki Fukumizu, Shigeki Kobayashi, Masaki Yamato
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Publication number: 20130301339Abstract: A control circuit controls a voltage applied to a memory cell array. A first electrode contacts to a first surface of a variable resistance element, while a second electrode contacts to a second surface of the variable resistance element. The first electrode is configured by a metal, and the second electrode is configured by a P type semiconductor. The control unit, when performing a setting operation of a memory cell, applies a voltage such that a current flows in a direction from the first electrode toward the second electrode.Type: ApplicationFiled: February 27, 2013Publication date: November 14, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hiroyuki FUKUMIZU, Shigeki Kobayashi, Yasuhiro Nojiri, Masaki Yamato, Takeshi Yamaguchi
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Patent number: 8569731Abstract: A nonvolatile memory device includes: at least one first interconnection extending in a first direction; at least one second interconnection disposed above the first interconnection and extending in a second direction nonparallel to the first direction; a memory cell disposed between the first interconnection and the second interconnection at an intersection of the first interconnection and the second interconnection and including a memory element; and an element isolation layer disposed between the memory cells. At least one dielectric film with a higher density than the element isolation layer is disposed on a sidewall surface of the memory cell.Type: GrantFiled: March 18, 2010Date of Patent: October 29, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takuya Konno, Hiroyuki Fukumizu, Kazuhito Nishitani
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Patent number: 8536556Abstract: A nonvolatile memory device includes: a first interconnection extending in a first direction; a second interconnection extending in a second direction nonparallel to the first direction; and a memory layer placed between the first interconnection and the second interconnection and reversibly transitioning between a first state and a second state by a current supplied via the first interconnection and the second interconnection. A cross section parallel to the first and the second direction of the memory layer decreases toward the second interconnection.Type: GrantFiled: March 18, 2010Date of Patent: September 17, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Hiroyuki Fukumizu
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Publication number: 20130237008Abstract: According to one embodiment, a method is disclosed for manufacturing a nonvolatile memory device. The nonvolatile memory device includes a memory cell connected to a first interconnect and a second interconnect. The method can include forming a first electrode film on the first interconnect. The method can include forming a layer including a plurality of carbon nanotubes dispersed inside an insulator on the first electrode film. At least one carbon nanotube of the plurality of carbon nanotubes is exposed from a surface of the insulator. The method can include forming a second electrode film on the layer. In addition, the method can include forming a second interconnect on the second electrode film.Type: ApplicationFiled: April 25, 2013Publication date: September 12, 2013Applicant: Kabushiki Kaisha ToshibaInventors: Yasuhiro NOJIRI, Hiroyuki FUKUMIZU, Shinichi NAKAO, Kei WATANABE, Kazuhiko YAMAMOTO, Ichiro MIZUSHIMA, Yoshio OZAWA
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Publication number: 20130235646Abstract: A memory cell array is configured as an arrangement of memory cells disposed at intersections of a plurality of first lines and a plurality of second lines formed so as to intersect one another, each of the memory cells comprising a variable resistance element. A control circuit selectively drives the first lines and the second lines. The variable resistance element is configured by a transition metal oxide film. An electrode connected to the variable resistance element includes a polysilicon electrode configured from polysilicon. A block layer is formed between the polysilicon electrode and the variable resistance element.Type: ApplicationFiled: August 31, 2012Publication date: September 12, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro NOJIRI, Hiroyuki Fukumizu, Katsuyuki Sekine, Yutaka Ishibashi
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Publication number: 20130234096Abstract: A diode layer includes a first impurity semiconductor layer that includes a first impurity acting as an acceptor and a second impurity semiconductor layer that includes a second impurity acting as a donor. One end of a first electrode layer contacts the diode layer. One end of a polysilicon layer contacts the other end of the first electrode layer. One end of a variable resistance layer contacts the other end of the polysilicon layer and is able to change a resistance value. A second electrode layer contacts the other end of the variable resistance layer. At least one of a first area and a second area contains a third impurity. The first area includes one end of the polysilicon layer, the second area includes the other end of the polysilicon layer. The third impurity differs from the first impurity and the second impurity.Type: ApplicationFiled: August 31, 2012Publication date: September 12, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Katsuyuki SEKINE, Yasuhiro Nojiri, Hiroyuki Fukumizu
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Publication number: 20130228737Abstract: According to an embodiment, a nonvolatile semiconductor memory device comprises memory cells in each of which are series-connected: a variable resistance element including a metal oxide; an electrode including a polysilicon layer and a SiGe layer formed between the polysilicon layer and the metal oxide; and a bipolar type current rectifying element.Type: ApplicationFiled: August 31, 2012Publication date: September 5, 2013Applicant: Kabushiki Kaisha ToshibaInventors: Hiroyuki FUKUMIZU, Yasuhiro Nojiri, Katsuyuki Sekine
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Patent number: 8519371Abstract: According to one embodiment, a nonvolatile memory device includes a substrate, a first electrode, a second electrode, and a memory. The first electrode is provided on the substrate. The second electrode crosses on the first electrode. The memory portion is provided between the first electrode and the second electrode. At least one of an area of a first memory portion surface of the memory portion opposed to the first electrode and an area of a second memory portion surface of the memory portion opposed to the second electrode is smaller than an area of a cross surface of the first electrode and the second electrode opposed to each other by the crossing.Type: GrantFiled: September 7, 2010Date of Patent: August 27, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Fukumizu, Naoya Hayamizu, Makiko Tange
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Patent number: 8471325Abstract: According to one embodiment, a nonvolatile memory device includes a substrate, a first electrode, a second electrode, a third electrode, a first memory portion and a second memory portion. The first electrode extends in a first direction and is provided on the substrate. The second electrode extends in a second direction crossing the first direction and is provided on the first electrode. The third electrode extends in a third direction crossing the second direction and is provided on the second electrode. The first memory portion is provided between the first and the second electrodes and has a first oxygen composition ratio and a first layer thickness. The second memory portion is provided between the second and the third electrodes and has at least one of a second oxygen composition ratio different from the first oxygen composition ratio and a second layer thickness different from the first layer thickness.Type: GrantFiled: September 20, 2010Date of Patent: June 25, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Fukumizu, Noriko Bota
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Patent number: 8455346Abstract: According to one embodiment, a method is disclosed for manufacturing a nonvolatile memory device. The nonvolatile memory device includes a memory cell connected to a first interconnect and a second interconnect. The method can include forming a first electrode film on the first interconnect. The method can include forming a layer including a plurality of carbon nanotubes dispersed inside an insulator on the first electrode film. At least one carbon nanotube of the plurality of carbon nanotubes is exposed from a surface of the insulator. The method can include forming a second electrode film on the layer. In addition, the method can include forming a second interconnect on the second electrode film.Type: GrantFiled: March 30, 2011Date of Patent: June 4, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Nojiri, Hiroyuki Fukumizu, Shinichi Nakao, Kei Watanabe, Kazuhiko Yamamoto, Ichiro Mizushima, Yoshio Ozawa
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Publication number: 20130119342Abstract: According to one embodiment, a method is disclosed for manufacturing a semiconductor memory device. The method can include introducing halogen in a contact layer with a resistance variation film including a metal oxide. The method can include diffusing the halogen from the contact layer to the resistance variation film by a thermal treatment.Type: ApplicationFiled: November 14, 2012Publication date: May 16, 2013Inventors: Takeshi YAMAGUCHI, Hiroyuki FUKUMIZU
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Patent number: 8378331Abstract: This nonvolatile semiconductor memory device comprises a memory cell array including memory cells arranged therein. Each of the memory cells is located at respective intersections between first wirings and second wirings and includes a variable resistance element. The variable resistance element comprises a thin film including carbon (C). The thin film includes a side surface along a direction of a current flowing in the memory cell. The side surface includes carbon nitride (CNx).Type: GrantFiled: February 17, 2010Date of Patent: February 19, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Satoh, Tsukasa Nakai, Kazuhiko Yamamoto, Motoya Kishida, Hiroyuki Fukumizu, Yasuhiro Nojiri
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Patent number: 8339834Abstract: According to one embodiment, a non-volatile semiconductor memory device includes: a first line; a second line intersecting with the first line; and a memory cell arranged at a position where the second line intersects with the first line, wherein, the memory cell includes: a variable resistance element; and a negative resistance element connected in series to the variable resistance element.Type: GrantFiled: September 15, 2010Date of Patent: December 25, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Tsukasa Nakai, Yasuhiro Nojiri, Shuichi Kuboi, Motoya Kishida, Akiko Nomachi, Masanobu Baba, Hiroyuki Fukumizu
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Patent number: 8334525Abstract: According to one embodiment, a variable resistance layer includes a mixture of a first compound and a second compound. The first compound includes carbon (C) as well as at least one element selected from a group of elements G1. The group of elements G1 consists of hydrogen (H), boron (B), nitrogen (N), silicon (Si), and titanium (Ti). The second compound includes at least one compound selected from a group of compounds G2. The group of compounds G2 consists of silicon oxide (SiO2), silicon oxynitride (SiON), silicon nitride (Si3N4), carbon nitride (C3N4), boron nitride (BN), aluminum nitride (AlN), aluminum oxide (Al2O3), and silicon carbide (SiC). Concentration of the first compound in the variable resistance layer is not less than 30 volume percent, and not more than 70 volume percent.Type: GrantFiled: June 29, 2010Date of Patent: December 18, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Tsukasa Nakai, Hiroyuki Fukumizu, Yasuhiro Nojiri, Motoya Kishida, Kazuyuki Yahiro, Yasuhiro Satoh
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Publication number: 20120273743Abstract: A nonvolatile semiconductor memory device includes: a first interconnect; a second interconnect at a position opposing the first interconnect; and a variable resistance layer between the first interconnect and the second interconnect, the variable resistance layer being capable of reversibly changing between a first state and a second state by a voltage applied via the first interconnect and the second interconnect or a current supplied via the first interconnect and the second interconnect, the first state having a first resistivity, the second state having a second resistivity higher than the first resistivity. Wherein the variable resistance layer has a compound of carbon and silicon as a main component and including hydrogen.Type: ApplicationFiled: November 29, 2010Publication date: November 1, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Shuichi Kuboi, Masayuki Takata, Tsukasa Nakai, Hiroyuki Fukumizu, Yasuhiro Nojiri, Kenichi Ootsuka
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Patent number: 8274816Abstract: According to one embodiment, a nonvolatile memory device includes a memory layer and a driver section. The memory layer has a first state having a first resistance under application of a first voltage, a second state having a second resistance higher than the first resistance under application of a second voltage higher than the first voltage, and a third state having a third resistance between the first resistance and the second resistance under application of a third voltage between the first voltage and the second voltage. The driver section is configured to apply at least one of the first voltage, the second voltage and the third voltage to the memory layer to record information in the memory layer.Type: GrantFiled: February 28, 2011Date of Patent: September 25, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Noriko Bota, Yasuhiro Nojiri, Hiroyuki Fukumizu, Takuya Konno, Kazuhito Nishitani
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Patent number: 8274821Abstract: A nonvolatile memory device, includes: a memory layer having a resistance changeable by performing at least one selected from applying an electric field and providing a current, the storage layer having a first major surface; a plurality of first electrodes provided on the first major surface; a plurality of probe electrodes disposed to face the plurality of first electrodes, the plurality of probe electrodes having a changeable relative positional relationship with the first electrodes; a drive unit connected to the plurality of probe electrodes to record information in the memory layer by causing at least the one selected from the electric field and the current between at least two of the plurality of first electrodes via the plurality of probe electrodes, the electric field having a component parallel to the first major surface, the current flowing in a direction having a component parallel to the first major surface.Type: GrantFiled: March 17, 2010Date of Patent: September 25, 2012Assignee: Kabushiki Kaisha ToshibaInventor: Hiroyuki Fukumizu
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Patent number: 8264866Abstract: According to one embodiment, a nonvolatile memory device includes a memory cell. The memory cell is connected to a first interconnection and a second interconnection and includes a plurality of layers. The plurality of layers includes a memory layer and a carbon nanotube-containing layer which is in contact with the memory layer and contains a plurality of carbon nanotubes.Type: GrantFiled: September 14, 2010Date of Patent: September 11, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Hiroyuki Fukumizu, Yasuhiro Nojiri, Tsukasa Nakai
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Patent number: 8258494Abstract: A nonvolatile memory device, includes: a lower side electrode aligned in a first direction; an upper side electrode positioned above the lower side electrode and aligned in a second direction intersecting the first direction; and a memory unit provided between the lower side electrode and the upper side electrode. At least one selected from the lower side electrode and the upper side electrode includes a first electrode and a second electrode, the first electrode having a forward-tapered side wall, the second electrode having a reverse-tapered side wall and being adjacent to the first electrode via an insulating layer in substantially identical plane.Type: GrantFiled: March 18, 2010Date of Patent: September 4, 2012Assignee: Kabushiki Kaisha ToshibaInventor: Hiroyuki Fukumizu