Patents by Inventor Yoshio Kawashima
Yoshio Kawashima 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: 8995170Abstract: A non-volatile memory device includes: a memory cell array including a plurality of memory cells each including a first variable resistance element and a first current steering element and a parameter generation circuit including a reference cell including a second variable resistance element and a second current steering element having the same current density-voltage characteristic as that of the first current steering element, wherein a conductive shorting layer for causing short-circuiting between the electrodes is formed on the side surfaces of the second variable resistance element.Type: GrantFiled: March 27, 2013Date of Patent: March 31, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Yoshio Kawashima, Yukio Hayakawa, Takumi Mikawa
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Patent number: 8952350Abstract: A non-volatile memory device of the present invention comprises a first electrode; a variable resistance layer formed on and above the first electrode; a second electrode formed on and above the variable resistance layer; a side wall protective layer having an insulativity and covering a side wall of the first electrode, a side wall of the variable resistance layer and a side wall of the second electrode; and an electrically-conductive layer connected to the second electrode; the non-volatile memory device including a connection layer which is provided between the second electrode and the electrically-conductive layer to connect the second electrode and the electrically-conductive layer to each other, and comprises an electrically-conductive material different from a material constituting the electrically-conductive layer; wherein the side wall protective layer extends across the second electrode to a position which is above an upper end of the second electrode and below an upper end of the connection layer sType: GrantFiled: September 26, 2013Date of Patent: February 10, 2015Assignee: Panasonic Intellectual Property Management Co., Ltd.Inventors: Hideaki Murase, Yoshio Kawashima, Atsushi Himeno
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Patent number: 8921200Abstract: A method of manufacturing a variable resistance nonvolatile memory element includes: forming a lower electrode layer above a substrate; forming, on the lower electrode layer, a variable resistance layer including an oxygen-deficient transition metal oxide; forming an upper electrode layer on the variable resistance layer; and forming a patterned mask on the upper electrode layer and etching the upper electrode layer, the variable resistance layer, and the lower electrode layer using the patterned mask. In the etching, at least the variable resistance layer is etched using an etching gas containing bromine.Type: GrantFiled: April 11, 2012Date of Patent: December 30, 2014Assignee: Panasonic CorporationInventors: Yoshio Kawashima, Takumi Mikawa, Shinichi Imai
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Patent number: 8889478Abstract: Provided is a method for manufacturing a variable resistance nonvolatile semiconductor memory element, and a nonvolatile semiconductor memory element which make it possible to operate at a low voltage and high speed when initial breakdown is caused, and exhibit favorable diode element characteristics. The method for manufacturing the nonvolatile semiconductor memory element includes, after forming a top electrode of a variable resistance element and at least before forming a top electrode of an MSM diode element, oxidizing to insulate a portion of a variable resistance film in a region around an end face of a variable resistance layer.Type: GrantFiled: November 18, 2011Date of Patent: November 18, 2014Assignee: Panasonic CorporationInventors: Takumi Mikawa, Yukio Hayakawa, Yoshio Kawashima, Takeki Ninomiya
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Publication number: 20140264249Abstract: A nonvolatile memory device includes a plurality of nonvolatile memory elements each having an upper electrode, a variable resistance layer, and a lower electrode; a first insulating layer embedding the plurality of nonvolatile memory elements, and ranging from a lowermost part of the lower electrode to a position higher than an uppermost part of the upper electrode in each of the nonvolatile memory elements; a second insulating layer being formed on the first insulating layer, and having an average size of vacancies larger than an average size of vacancies included in the first insulating layer, or having an average carbon concentration higher than an average carbon concentration of the first insulating layer; and a conductive layer penetrating the second insulating layer and a part of the first insulating layer and being connected to at least one of the upper electrodes included in the nonvolatile memory elements.Type: ApplicationFiled: March 13, 2014Publication date: September 18, 2014Applicant: Panasonic CorporationInventors: Satoru ITO, Yoshio KAWASHIMA, Yukio HAYAKAWA, Takumi MIKAWA
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Publication number: 20140203234Abstract: A variable resistance nonvolatile memory element includes: first and second electrode layers; a first variable resistance layer between the first and second electrode layers; and a second variable resistance layer between the second electrode layer and the first variable resistance layer and having a higher resistance value than the first variable resistance layer. When viewed in a direction perpendicular to the major surface of the second variable resistance layer, an outline of the second variable resistance layer is located inwardly of the outline of any one of the second electrode layer and the first variable resistance layer, and an outline of a face of the second variable resistance layer, the face being in contact with the first variable resistance layer is located inwardly of an outline of a face of the first variable resistance layer, the face being in contact with the second variable resistance layer.Type: ApplicationFiled: January 18, 2013Publication date: July 24, 2014Applicant: Panasonic CorporationInventors: Takeki Ninomiya, Takeshi Takagi, Koji Katayama, Yoshio Kawashima
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Patent number: 8785238Abstract: The method includes: forming a lower electrode layer above a substrate; forming a variable resistance layer on the lower electrode layer; forming an upper electrode layer on the variable resistance layer; forming a hard mask layer on the upper electrode layer; forming a photoresist mask on the hard mask layer; forming a hard mask by performing etching on the hard mask layer using the photoresist mask; and forming a nonvolatile memory element by performing etching on the upper electrode layer, the variable resistance layer, and the lower electrode layer, using the hard mask. In the forming of a photoresist mask, the photoresist mask is formed to have corner portions which recede toward the center portion in planar view.Type: GrantFiled: June 30, 2011Date of Patent: July 22, 2014Assignee: Panasonic CorporationInventors: Yoshio Kawashima, Takumi Mikawa
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Publication number: 20140175369Abstract: A method of manufacturing a non-volatile memory device comprises: forming a first electrode layer; a variable resistance material layer, a second electrode layer; and a hard mask layer, forming a first resist mask extending in a first direction on the hard mask layer; forming a first hard mask extending in the first direction by etching the hard mask layer using the first resist mask; forming a second resist mask extending in a second direction, on the first hard mask such that the width of the second resist mask is greater than the width of the first resist mask; forming a second hard mask by etching the first hard mask using the second resist mask; and forming a variable resistance element by patterning, by etching the second electrode layer, the variable resistance material layer and the first electrode layer using the second hard mask.Type: ApplicationFiled: December 23, 2013Publication date: June 26, 2014Applicant: PANASONIC CORPORATIONInventors: Hideaki MURASE, Satoru ITO, Yoshio KAWASHIMA, Takumi MIKAWA
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Publication number: 20140145136Abstract: A non-volatile memory device of the present invention comprises a first electrode; a variable resistance layer formed on and above the first electrode; a second electrode formed on and above the variable resistance layer; a side wall protective layer having an insulativity and covering a side wall of the first electrode, a side wall of the variable resistance layer and a side wall of the second electrode; and an electrically-conductive layer which is in contact with the second electrode; wherein the electrically-conductive layer covers an entire of the second electrode and at least a portion of the side wall protective layer located outward relative to the second electrode, when viewed from a thickness direction; and the side wall protective layer extends across the second electrode to a position above an upper end of the second electrode such that an upper end of the side wall protective layer is located above the upper end of the second electrode, when viewed from a side.Type: ApplicationFiled: September 26, 2013Publication date: May 29, 2014Applicant: PANASONIC CORPORATIONInventors: Hideaki MURASE, Yoshio KAWASHIMA, Atsushi HIMENO
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Publication number: 20140113430Abstract: A method of manufacturing a semiconductor device according to the present invention includes: forming a lower electrode above a substrate; forming, above the lower electrode, a first variable resistance layer comprising a first metal oxide; forming a step region in the first variable resistance layer by collision of ions excited by plasma; removing residue of the first variable resistance layer created in the forming of the step region; forming a second variable resistance layer which covers the step region of the first variable resistance layer, comprises a second metal oxide having a degree of oxygen deficiency lower than a degree of oxygen deficiency of the first metal oxide, and has a bend on a step formed along an edge of the step region; and forming an upper electrode above the second variable resistance layer.Type: ApplicationFiled: October 9, 2012Publication date: April 24, 2014Applicant: PANASONIC CORPORATIONInventors: Yukio Hayakawa, Atsushi Himeno, Hideaki Murase, Yoshio Kawashima, Takumi Mikawa
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Publication number: 20140110659Abstract: A method of manufacturing a nonvolatile memory device includes: forming a first electrode; forming, above the first electrode, a metal oxide material layer including a first metal oxide; forming a mask above part of the metal oxide material layer main surface; forming, in a region of the metal oxide material layer not covered by the mask, a high oxygen concentration region including a second metal oxide having a lower degree of oxygen deficiency than the first metal oxide; removing the mask; forming, above a first variable resistance layer including the high oxygen concentration region and a low oxygen concentration region that is a region of the metal oxide material layer other than the high oxygen concentration region, a second variable resistance layer including a third metal oxide having a lower degree of oxygen deficiency than the first metal oxide; and forming a second electrode above the second variable resistance layer.Type: ApplicationFiled: March 27, 2013Publication date: April 24, 2014Applicant: Panasonic CorporationInventors: Hideaki Murase, Yoshio Kawashima, Atsushi Himeno, Takumi Mikawa
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Publication number: 20140097396Abstract: A non-volatile memory device of the present invention comprises a first electrode; a variable resistance layer formed on and above the first electrode; a second electrode formed on and above the variable resistance layer; a side wall protective layer having an insulativity and covering a side wall of the first electrode, a side wall of the variable resistance layer and a side wall of the second electrode; and an electrically-conductive layer connected to the second electrode; the non-volatile memory device including a connection layer which is provided between the second electrode and the electrically-conductive layer to connect the second electrode and the electrically-conductive layer to each other, and comprises an electrically-conductive material different from a material constituting the electrically-conductive layer; wherein the side wall protective layer extends across the second electrode to a position which is above an upper end of the second electrode and below an upper end of the connection layer sType: ApplicationFiled: September 26, 2013Publication date: April 10, 2014Applicant: PANASONIC CORPORATIONInventors: Hideaki MURASE, Yoshio KAWASHIMA, Atsushi HIMENO
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Publication number: 20140098595Abstract: A non-volatile memory device includes: a memory cell array including a plurality of memory cells each including a first variable resistance element and a first current steering element and a parameter generation circuit including a reference cell including a second variable resistance element and a second current steering element having the same current density-voltage characteristic as that of the first current steering element, wherein a conductive shorting layer for causing short-circuiting between the electrodes is formed on the side surfaces of the second variable resistance element.Type: ApplicationFiled: March 27, 2013Publication date: April 10, 2014Applicant: Panasonic CorporationInventors: Yoshio Kawashima, Yukio Hayakawa, Takumi Mikawa
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Publication number: 20140063913Abstract: A non-volatile memory device includes: a memory cell array including a plurality of memory cells each including a variable resistance element and a first current steering element; and a current steering element parameter generation circuit. The current steering element parameter generation circuit includes: a third line placed between a substrate and a second interlayer dielectric; a fourth line placed above the second interlayer dielectric; and a second current steering element which is connected between the third line and the fourth line without the variable resistance element being interposed therebetween when the variable resistance element is removed between the third line and the fourth line and has the same non-linear current steering characteristics as the first current steering element.Type: ApplicationFiled: December 17, 2012Publication date: March 6, 2014Applicant: Panasonic CorporationInventors: Yoshio Kawashima, Yukio Hayakawa
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Publication number: 20140024197Abstract: A method of manufacturing a variable resistance nonvolatile memory element includes: forming a lower electrode layer above a substrate; forming, on the lower electrode layer, a variable resistance layer including an oxygen-deficient transition metal oxide; forming an upper electrode layer on the variable resistance layer; and forming a patterned mask on the upper electrode layer and etching the upper electrode layer, the variable resistance layer, and the lower electrode layer using the patterned mask, wherein in the etching, at least the variable resistance layer is etched using an etching gas containing bromine.Type: ApplicationFiled: April 11, 2012Publication date: January 23, 2014Inventors: Yoshio Kawashima, Takumi Mikawa, Shinichi Imai
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Patent number: 8610102Abstract: A nonvolatile memory device (10A) comprises an upper electrode layer (2); a lower electrode layer (4); a resistance variable layer (3) sandwiched between the upper electrode layer (2) and the lower electrode layer (4); and a charge diffusion prevention mask (1A) formed on a portion of the upper electrode layer (2); wherein the resistance variable layer (3) includes a first film comprising oxygen-deficient transition metal oxide and a second film comprising oxygen-deficient transition metal oxide which is higher in oxygen content than the first film; at least one of the upper electrode layer (2) and the lower electrode layer (4) comprises a simple substance or alloy of a platinum group element; and the charge diffusion prevention mask (1A) is insulative, and is lower in etching rate of dry etching than the upper electrode layer (2) and the lower electrode layer (4).Type: GrantFiled: June 16, 2010Date of Patent: December 17, 2013Assignee: Panasonic CorporationInventors: Yoshio Kawashima, Takumi Mikawa
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Patent number: 8574957Abstract: An object of the present invention is to provide a method for manufacturing a variable resistance nonvolatile semiconductor memory element which can operate at a low voltage and high speed when initial breakdown is caused, and inhibit oxidization of a contact plug. The method for manufacturing the variable resistance nonvolatile semiconductor memory element, which includes a bottom electrode, a variable resistance layer, and a top electrode which are formed above a contact plug, includes oxidizing to insulate an end portion of the variable resistance layer prior to forming a bottom electrode by patterning a first conductive film.Type: GrantFiled: November 10, 2011Date of Patent: November 5, 2013Assignee: Panasonic CorporationInventors: Takumi Mikawa, Yukio Hayakawa, Takeki Ninomiya, Yoshio Kawashima
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Patent number: 8537605Abstract: A nonvolatile semiconductor memory device (100) comprises a substrate (102) provided with a transistor (101); a first interlayer insulating layer (103) formed over the substrate to cover the transistor; a first contact plug (104) formed in the first interlayer insulating layer and electrically connected to either of a drain electrode (101a) or a source electrode (101b) of the transistor, and a second contact plug (105) formed in the first interlayer insulating layer and electrically connected to the other of the drain electrode or the source electrode of the transistor; a resistance variable layer (106) formed to cover a portion of the first contact plug; a first wire (107) formed on the resistance variable layer; and a second wire (108) formed to cover a portion of the second contact plug; an end surface of the resistance variable layer being coplanar with an end surface of the first wire.Type: GrantFiled: February 9, 2009Date of Patent: September 17, 2013Assignee: Panasonic CorporationInventors: Takumi Mikawa, Yoshio Kawashima, Koji Arita, Takeki Ninomiya
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Patent number: 8530321Abstract: A variable resistance element comprises, when M is a transition metal element, O is oxygen, and x and y are positive numbers satisfying y>x; a lower electrode; a first oxide layer formed on the lower electrode and comprising MOx when a content ratio of O with respect to M is x; a second oxide layer formed on the first oxide layer and comprising MOy when a content ratio of O with respect to M is y; an upper electrode formed on the second oxide layer; a protective layer formed on the upper electrode and comprising an electrically conductive material having a composition different from a composition of the upper electrode; an interlayer insulating layer formed to cover the protective layer; and an upper contact plug formed inside an upper contact hole penetrating the interlayer insulating layer.Type: GrantFiled: December 14, 2010Date of Patent: September 10, 2013Assignee: Panasonic CorporationInventors: Takeki Ninomiya, Yoshio Kawashima, Yukio Hayakawa, Takumi Mikawa
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Patent number: 8492743Abstract: A nonvolatile memory device includes a substrate, a lower electrode formed above said substrate, a second variable resistance layer formed above said lower electrode and comprising a second transitional metal oxide, a first variable resistance layer formed above said second variable resistance layer and comprising a first transitional metal oxide having an oxygen content that is lower than an oxygen content of the second transitional metal oxide, and an upper electrode formed above said first variable resistance layer. A step is formed in an interface between said lower electrode and said second variable resistance layer. The second variable resistance layer is formed covering the step and has a bend above the step.Type: GrantFiled: January 29, 2013Date of Patent: July 23, 2013Assignee: Panasonic CorporationInventors: Takumi Mikawa, Yoshio Kawashima