Patents by Inventor Tsukasa Nakai
Tsukasa Nakai 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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Patent number: 8431920Abstract: According to one embodiment, an information recording and reproducing device includes a recording layer which includes a typical element and a transition element, and stores a state of a first electric resistivity and a state of a second electric resistivity different from the first electric resistivity by a movement of the typical element, and an electrode layer which is disposed at one end of the recording layer to apply a voltage or a current to the recording layer. The recording layer includes a first region which is in contact with the electrode layer and the electrode layer includes a second region which is in contact with the recording layer. The first and second regions are opposite to each other. And the first and second regions include the typical element, and a concentration of the typical element in the second region is higher than that in the first region.Type: GrantFiled: September 17, 2010Date of Patent: April 30, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Chikayoshi Kamata, Takayuki Tsukamoto, Takeshi Yamaguchi, Tsukasa Nakai, Takahiro Hirai, Shinya Aoki, Kohichi Kubo
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Patent number: 8416606Abstract: According to one embodiment, an information recording and reproducing device includes a recording layer and a driving unit. The recording layer includes a first layer containing a first compound. The first compound includes a first positive ion element. The first positive ion element is made of a transition metal element and serves as a first positive ion. The second positive ion element serves as a second positive ion. The driving unit is configured to generate a phase change in the recording layer and to record information by at least one of application of a voltage and application of a current to the recording layer. The coordination number of the first positive ion element at a position of a second coordination of the second positive ion element is 80% or more and less than 100% of the coordination number when the first compound is assumed to be a perfect crystal.Type: GrantFiled: March 4, 2011Date of Patent: April 9, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Tsukasa Nakai, Chikayoshi Kamata, Mariko Hayashi, Fumihiko Aiga, Takeshi Yamaguchi
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Patent number: 8395138Abstract: A nonvolatile semiconductor memory using carbon related films as variable resistance films includes bottom electrodes formed above a substrate, buffer layers formed on the bottom electrodes and each formed of a film containing nitrogen and containing carbon as a main component, variable resistance films formed on the buffer layers and each formed of a film containing carbon as a main component and the electrical resistivity thereof being changed according to application of voltage or supply of current, and top electrodes formed on the variable resistance films.Type: GrantFiled: August 21, 2009Date of Patent: March 12, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Kazuhiko Yamamoto, Kazuyuki Yahiro, Tsukasa Nakai
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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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Patent number: 8305797Abstract: According to one embodiment, an information recording/reproducing device includes a recording layer and a driver section. The recording layer has a first layer including a first compound. The first compound includes a mixed crystal of a first oxide containing a first metallic element and a second oxide. The second oxide has a crystal structure being same as the first oxide and contains a second metallic element different from the first metallic element. The driver section is configured to produce state change in the recording layer to record information by at least one of application of voltage to the recording layer and passage of current to the recording layer. Composition ratio of an element having a smaller ionic radius of the first and second metallic elements is not less than percolation threshold of a lattice formed of ions of the first and second metallic elements based on the crystal structure.Type: GrantFiled: March 9, 2011Date of Patent: November 6, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Shinya Aoki, Kohichi Kubo, Takayuki Tsukamoto, Takahiro Hirai, Chikayoshi Kamata, Tsukasa Nakai
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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: 8269205Abstract: According to one embodiment, an information recording and reproducing device includes a first layer, a second layer and a recording layer. The recording layer is provided between the first layer and the second layer and being capable of reversibly changing between a first state having a first resistance and a second state having a second resistance higher than the first resistance. The recording layer includes a first compound layer and a second compound layer. The first compound layer contains a first compound. The first compound includes a first cation element and a second cation element of a type different from the first cation element. The second compound layer contains a second compound. The second compound includes a transition element having a d-orbital partially filled with electron, and the second compound includes a void site capable of storing at least one of the first cation element and the second cation element.Type: GrantFiled: September 20, 2010Date of Patent: September 18, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Kohichi Kubo, Chikayoshi Kamata, Takayuki Tsukamoto, Shinya Aoki, Takahiro Hirai, Tsukasa Nakai, Toshiro Hiraoka
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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: 8232042Abstract: According to one embodiment, a storage medium comprises a transparent resin substrate on which a groove is formed, a recording layer formed on the groove on the transparent resin substrate, the recording layer using an organic dye material and recording information with a light beam of 620 nm or less in wavelength, a reflection layer formed on the recording layer, and a prevention layer formed between the recording layer and the reflection layer, the prevention layer preventing degradation of characteristics of the reflection layer.Type: GrantFiled: March 30, 2006Date of Patent: July 31, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Tsukasa Nakai, Seiji Morita, Koji Takazawa, Yasuaki Ootera, Naoki Morishita, Kazuyo Umezawa, Hideo Ando
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Patent number: 8207518Abstract: According to one embodiment, an information recording and reproducing device includes a first layer, a second layer and a recording layer. The recording layer is provided between the first layer and the second layer and being capable of reversibly changing between a first state having a first resistance and a second state having a second resistance higher than the first resistance by a current supplied via the first layer and the second layer. The recording layer includes a first compound layer and an insulating layer. The first compound layer contains a first compound. The first compound includes a first cation element and a second cation element of a type different from the first cation element. The insulating layer contains a third compound, and the third compound includes an element selected from group 1 to 4 elements and group 12 to 17 elements in the periodic table.Type: GrantFiled: September 20, 2010Date of Patent: June 26, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Kohichi Kubo, Chikayoshi Kamata, Takayuki Tsukamoto, Shinya Aoki, Takahiro Hirai, Tsukasa Nakai, Toshiro Hiraoka
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Publication number: 20120061732Abstract: According to one embodiment, an information recording/reproducing device including a semiconductor substrate, a first interconnect layer on the semiconductor substrate, a first memory cell array layer on the first interconnect layer, and a second interconnect layer on the first memory cell array layer. The first memory cell array layer comprises an insulating layer having an alignment mark, and a stacked layer structure on the insulating layer and including a storage layer and an electrode layer. All of the layers in the stacked layer structure comprises a material with a permeability of visible light of 1% or more.Type: ApplicationFiled: September 9, 2011Publication date: March 15, 2012Inventors: Takahiro HIRAI, Tsukasa NAKAI, Kohichi KUBO, Chikayoshi KAMATA, Takayuki TSUKAMOTO, Shinya AOKI
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Patent number: 8089796Abstract: According to one embodiment, an information recording and reproducing device includes a first layer, a second layer and a recording layer. The recording layer is provided between the first and second layers and is capable of reversibly transitioning between a first state and a second state with a resistance higher than in the first state. One of the first and second layers includes a resistivity distribution layer perpendicular to a stacking direction of the first and second layers, and the recording layer. The resistivity distribution layer includes a low and a high resistivity portion. Resistivity of the high resistivity portion is higher than resistivity of the low resistivity portion. The low resistivity portion contains a transition element identical to a transition element contained in the high resistivity portion.Type: GrantFiled: September 20, 2010Date of Patent: January 3, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Takeshi Yamaguchi, Chikayoshi Kamata, Tsukasa Nakai, Takahiro Hirai, Shinya Aoki, Kohichi Kubo
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Publication number: 20110303888Abstract: According to one embodiment, a nonvolatile memory device includes a memory cell connected to a first interconnect and a second interconnect. The memory cell includes a plurality of layers. The plurality of layers includes a carbon-containing memory layer sandwiched between a first electrode film and a second electrode film and a carbon-containing barrier layer provided at least one of between the first electrode film and the memory layer and between the second electrode film and the memory layer. The barrier layer has lower electrical resistivity than the memory layer.Type: ApplicationFiled: March 10, 2011Publication date: December 15, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Hiroyuki FUKUMIZU, Yasuhiro Nojiri, Tsukasa Nakai, Kazuhiko Yamamoto
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Publication number: 20110216576Abstract: According to one embodiment, an information recording/reproducing device includes a recording layer and a driver section. The recording layer has a first layer including a first compound. The first compound includes a mixed crystal of a first oxide containing a first metallic element and a second oxide. The second oxide has a crystal structure being same as the first oxide and contains a second metallic element different from the first metallic element. The driver section is configured to produce state change in the recording layer to record information by at least one of application of voltage to the recording layer and passage of current to the recording layer. Composition ratio of an element having a smaller ionic radius of the first and second metallic elements is not less than percolation threshold of a lattice formed of ions of the first and second metallic elements based on the crystal structure.Type: ApplicationFiled: March 9, 2011Publication date: September 8, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Shinya Aoki, Kohichi Kubo, Takayuki Tsukamoto, Takahiro Hirai, Chikayoshi Kamata, Tsukasa Nakai
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Publication number: 20110216582Abstract: According to one embodiment, an information recording and reproducing device includes a recording layer and a driving unit. The recording layer includes a first layer containing a first compound. The first compound includes a first positive ion element. The first positive ion element is made of a transition metal element and serves as a first positive ion. The second positive ion element serves as a second positive ion. The driving unit is configured to generate a phase change in the recording layer and to record information by at least one of application of a voltage and application of a current to the recording layer. The coordination number of the first positive ion element at a position of a second coordination of the second positive ion element is 80% or more and less than 100% of the coordination number when the first compound is assumed to be a perfect crystal.Type: ApplicationFiled: March 4, 2011Publication date: September 8, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Tsukasa Nakai, Chikayoshi Kamata, Mariko Hayashi, Fumihiko Aiga, Takeshi Yamaguchi
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Publication number: 20110205781Abstract: 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: ApplicationFiled: September 15, 2010Publication date: August 25, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Tsukasa Nakai, Yasuhiro Nojiri, Shuichi Kuboi, Motoya Kishida, Akiko Nomachi, Masanobu Baba, Hiroyuki Fukumizu
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Publication number: 20110069525Abstract: 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: ApplicationFiled: September 14, 2010Publication date: March 24, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Hiroyuki FUKUMIZU, Yasuhiro Nojiri, Tsukasa Nakai
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Publication number: 20110068319Abstract: According to one embodiment, an information recording and reproducing device includes a stacked body. The stacked body includes a first layer, a second layer and a recording layer provided between the first layer and the second layer. The recording layer includes a phase-change material and a crystal nucleus. The phase-change material is capable of reversely changing between a crystal state and an amorphous state by a current supplied via the first layer and the second layer. The crystal nucleus is provided in contact with the phase-change material and includes a crystal nucleus material having a crystal structure identical to a crystal structure of the crystal state of the phase-change material, and a crystal nucleus coating provided on a surface of the crystal nucleus material and having a composition different from a composition of the crystal nucleus material.Type: ApplicationFiled: September 20, 2010Publication date: March 24, 2011Applicant: Kabushiki Kaisha ToshibaInventors: Takayuki TSUKAMOTO, Tsukasa NAKAI, Akira KIKITSU, Takeshi YAMAGUCHI, Sumio ASHIDA