Patents by Inventor Seje TAKAKI
Seje TAKAKI 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: 10707314Abstract: A stack including doped semiconductor strips, a one-dimensional array of gate electrode strips, and a dielectric matrix layer is formed over a substrate. A two-dimensional array of openings is formed through the dielectric matrix layer and the one-dimensional array of gate electrode strips. A two-dimensional array of tubular gate electrode portions is formed in the two-dimensional array of openings. Each of the tubular gate electrode portions is formed directly on a respective one of the gate electrode strips. Gate dielectrics are formed on inner sidewalls of the tubular gate electrode portions. Vertical semiconductor channels are formed within each of the gate dielectrics by deposition of a semiconductor material. A two-dimensional array of vertical field effect transistors including surrounding gate electrodes is formed.Type: GrantFiled: September 29, 2017Date of Patent: July 7, 2020Assignee: SANDISK TECHNOLOGIES LLCInventors: Seje Takaki, Jongsun Sel, Hisakazu Otoi, Chao Feng Yeh
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Patent number: 10541273Abstract: A method is provided that includes forming a transistor by forming a gate dielectric layer above a substrate, forming a spacer dielectric layer above the gate dielectric layer, and forming a gate adjacent the gate dielectric layer and above the spacer dielectric layer.Type: GrantFiled: November 28, 2017Date of Patent: January 21, 2020Assignee: SanDisk Technologies LLCInventor: Seje Takaki
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Publication number: 20190165044Abstract: A method is provided that includes forming a transistor by forming a gate dielectric layer above a substrate, forming a spacer dielectric layer above the gate dielectric layer, and forming a gate adjacent the gate dielectric layer and above the spacer dielectric layer.Type: ApplicationFiled: November 28, 2017Publication date: May 30, 2019Applicant: SanDisk Technologies LLCInventor: Seje Takaki
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Resistive random access memory device containing replacement word lines and method of making thereof
Patent number: 10283710Abstract: A method of forming a resistive memory device includes forming an alternating stack of insulating layers and sacrificial material layers that extend along a first horizontal direction over a substrate, forming a laterally alternating sequence of vertical conductive lines and dielectric pillar structures that alternate along the first horizontal direction on sidewalls of the alternating stack, forming lateral recesses by removing the sacrificial material layers selective to the insulating layers, selectively growing resistive memory material portions from physically exposed surfaces of the vertical conductive lines in the lateral recesses, and forming electrically conductive layers over the resistive memory material portions in the lateral recesses.Type: GrantFiled: September 5, 2017Date of Patent: May 7, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Shin Kikuchi, Seje Takaki -
Publication number: 20190103467Abstract: A stack including doped semiconductor strips, a one-dimensional array of gate electrode strips, and a dielectric matrix layer is formed over a substrate. A two-dimensional array of openings is formed through the dielectric matrix layer and the one-dimensional array of gate electrode strips. A two-dimensional array of tubular gate electrode portions is formed in the two-dimensional array of openings. Each of the tubular gate electrode portions is formed directly on a respective one of the gate electrode strips. Gate dielectrics are formed on inner sidewalls of the tubular gate electrode portions. Vertical semiconductor channels are formed within each of the gate dielectrics by deposition of a semiconductor material. A two-dimensional array of vertical field effect transistors including surrounding gate electrodes is formed.Type: ApplicationFiled: September 29, 2017Publication date: April 4, 2019Inventors: Seje TAKAKI, Jongsun SEL, Hisakazu OTOI, Chao Feng YEH
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RESISTIVE RANDOM ACCESS MEMORY DEVICE CONTAINING REPLACEMENT WORD LINES AND METHOD OF MAKING THEREOF
Publication number: 20190074441Abstract: A method of forming a resistive memory device includes forming an alternating stack of insulating layers and sacrificial material layers that extend along a first horizontal direction over a substrate, forming a laterally alternating sequence of vertical conductive lines and dielectric pillar structures that alternate along the first horizontal direction on sidewalls of the alternating stack, forming lateral recesses by removing the sacrificial material layers selective to the insulating layers, selectively growing resistive memory material portions from physically exposed surfaces of the vertical conductive lines in the lateral recesses, and forming electrically conductive layers over the resistive memory material portions in the lateral recesses.Type: ApplicationFiled: September 5, 2017Publication date: March 7, 2019Inventors: Shin KIKUCHI, Seje TAKAKI -
Publication number: 20190051703Abstract: A two-dimensional array of vertical field effect transistors is provided, which includes a one-dimensional array of ladder-shaped gate electrode lines. Each of the ladder-shaped gate electrode lines includes a pair of rail portions that laterally extend along a first horizontal direction and spaced among one another along a second horizontal direction and rung portions extending between the pair of rail portions along the second horizontal direction. The vertical field effect transistors include gate dielectrics located in each opening defined by a neighboring pair of rung portions, and vertical semiconductor channels laterally surrounded by a respective one of the gate dielectrics and extending along a vertical direction. The two-dimensional array of vertical field effect transistors can be employed to select vertical bit lines of a three-dimensional ReRAM device.Type: ApplicationFiled: August 9, 2017Publication date: February 14, 2019Inventors: Jongsun SEL, Hisakazu OTOI, Seje TAKAKI, Tuan PHAM
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Patent number: 10115895Abstract: Dielectric wall structures are formed through a stack of a doped semiconductor material layer, a planar insulating spacer layer, and a sacrificial matrix layer. Gate electrode rails are formed through the dielectric wall structures and the sacrificial matrix layer. A two-dimensional array of rectangular openings is formed by removing remaining portions of the sacrificial matrix layer. A two-dimensional array of tubular gate electrode portions is formed in the two-dimensional array of rectangular openings. Gate dielectrics are formed on sidewalls of the tubular gate electrode portions. Vertical semiconductor channels are formed within each of the gate dielectrics by deposition of a semiconductor material. A two-dimensional array of vertical field effect transistors including surround gates is formed, which may be employed as access transistors of a three-dimensional memory device.Type: GrantFiled: September 26, 2017Date of Patent: October 30, 2018Assignee: SANDISK TECHNOLOGIES LLCInventors: Seje Takaki, Jongsun Sel, Hisakazu Otoi
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Patent number: 10096654Abstract: An alternating material stack of insulator lines and first electrically conductive material layers is formed over a substrate, and is patterned to provide alternating stacks of insulating layers and first electrically conductive lines. A metal can be selectively deposited on the physically exposed sidewalls of the first electrically conductive material layers to form metal lines, while not growing from the surfaces of the insulator lines. The metal lines are oxidized to form metal oxide lines that are self-aligned to the sidewalls of the first electrically conductive lines. Vertically extending second electrically conductive lines can be formed as a two-dimensional array of generally pillar-shaped structures between the alternating stacks of the insulator lines and the first electrically conductive lines. Each portion of the metal oxide lines at junctions of first and second electrically conductive lines constitute a resistive memory element for a resistive random access memory (ReRAM) device.Type: GrantFiled: September 11, 2015Date of Patent: October 9, 2018Assignee: SANDISK TECHNOLOGIES LLCInventors: Shin Kikuchi, Kazushi Komeda, Takuya Futase, Teruyuki Mine, Seje Takaki, Eiji Hayashi, Toshihide Tobitsuka
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Patent number: 9754999Abstract: A method is provided that includes forming a transistor by forming a gate disposed in a first direction above a substrate, the gate including a first bridge portion and a second bridge portion, forming the first bridge portion extending in the first direction and disposed near a top of the gate, and forming the second bridge portion extending in the first direction and disposed near a bottom of the gate.Type: GrantFiled: August 18, 2016Date of Patent: September 5, 2017Assignee: SanDisk Technologies LLCInventors: Seje Takaki, Manabu Hayashi, Ryousuke Itou, Takuro Maede, Kengo Kajiwara, Tetsuya Yamada, Yusuke Oda
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Patent number: 9748172Abstract: A 3D nonvolatile memory has memory elements arranged in a three-dimensional pattern with a plurality of memory layers stacked over a semiconductor substrate. It has a 2D array of vertical bit lines and a plurality of staircase word lines. Each staircase word line has a series of alternating segments and risers and traverses the plurality of memory layers with a segment in each memory layer. The plurality of staircase word lines have their segments lined up to form a 2D array of stacks of segments. Riser for a pair of segments from each adjacent stacks at different memory layers is provided by a conductive sidewall layer of a stairwell disposed between the adjacent stacks. Multiple insulated conductive sidewall layers provide multiple risers for the adjacent stacks. Layer-by-layer stairwell excavation and sidewall processes between adjacent stacks create risers for different pairs of segments between stacks to form the staircase word lines.Type: GrantFiled: February 13, 2017Date of Patent: August 29, 2017Assignee: SanDisk Technologies LLCInventor: Seje Takaki
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Patent number: 9698202Abstract: Resistive random access memory (ReRAM) array includes line stack structures located over a substrate. The line stack structures are laterally spaced apart along a first horizontal direction, and extend along a second horizontal direction that is different from the first horizontal direction. Each line stack structure comprises an alternating plurality of word lines and bit lines. An intervening line stack including a memory material line structure, an intrinsic semiconductor material line structure, and a doped semiconductor material line structure is located between each vertically neighboring pair of a word line and a bit line within the alternating plurality of word lines and bit lines. A two-dimensional array of vertical selector lines functions as gate electrodes that activates a semiconductor channel between a word line and a bit line. Resistance of the memory material line structure contacting the activated semiconductor channel can be programmed and/or measured within the ReRAM array.Type: GrantFiled: March 2, 2015Date of Patent: July 4, 2017Assignee: SANDISK TECHNOLOGIES LLCInventor: Seje Takaki
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Patent number: 9673257Abstract: A method is provided that includes forming a transistor by forming a first a rail gate disposed in a first direction above a substrate, forming a second rail gate disposed in a second direction above the substrate, the second direction perpendicular to the first direction, and forming a bridge section disposed between the first rail gate and the second rail gate.Type: GrantFiled: June 3, 2016Date of Patent: June 6, 2017Assignee: SanDisk Technologies LLCInventors: Seje Takaki, Manabu Hayashi, Akira Nakada, Ryousuke Itou, Takuro Maede, Kengo Kajiwara, Tetsuya Yamada
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Publication number: 20170154845Abstract: A 3D nonvolatile memory has memory elements arranged in a three-dimensional pattern with a plurality of memory layers stacked over a semiconductor substrate. It has a 2D array of vertical bit lines and a plurality of staircase word lines. Each staircase word line has a series of alternating segments and risers and traverses the plurality of memory layers with a segment in each memory layer. The plurality of staircase word lines have their segments lined up to form a 2D array of stacks of segments. Riser for a pair of segments from each adjacent stacks at different memory layers is provided by a conductive sidewall layer of a stairwell disposed between the adjacent stacks. Multiple insulated conductive sidewall layers provide multiple risers for the adjacent stacks. Layer-by-layer stairwell excavation and sidewall processes between adjacent stacks create risers for different pairs of segments between stacks to form the staircase word lines.Type: ApplicationFiled: February 13, 2017Publication date: June 1, 2017Applicant: SANDISK TECHNOLOGIES LLCInventor: Seje Takaki
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Patent number: 9646880Abstract: A method is provided for forming a monolithic three-dimensional memory array. The method includes forming a first vertically-oriented polysilicon pillar above a substrate, the first vertically-oriented polysilicon pillar surrounded by a dielectric material, removing the first vertically-oriented polysilicon pillar to form a first void in the dielectric material, and filling the first void with a conductive material to form a first via.Type: GrantFiled: January 14, 2016Date of Patent: May 9, 2017Assignee: SanDisk Technologies LLCInventors: Seje Takaki, Teruyuki Mine
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Patent number: 9613689Abstract: A three-dimensional memory device includes an alternating stack of word lines and insulating layers, a plurality of gate lines, a plurality of global bit lines, and a plurality of local bit lines contacting a respective gate line and global bit line. A plurality of memory elements is located at each overlap region between the word lines and the local bit lines. A plurality of diodes located in electrical series between each of the local bit lines and the respective one of the plurality of gate lines. A plurality of selector elements located in electrical series between each of the local bit lines and the respective one of the plurality of global bit lines. The plurality of selector elements includes a material that provides a conductivity change of at least one order of magnitude upon application of a voltage.Type: GrantFiled: July 8, 2016Date of Patent: April 4, 2017Assignee: SANDISK TECHNOLOGIES LLCInventor: Seje Takaki
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Publication number: 20170077184Abstract: An alternating material stack of insulator lines and first electrically conductive material layers is formed over a substrate, and is patterned to provide alternating stacks of insulating layers and first electrically conductive lines. A metal can be selectively deposited on the physically exposed sidewalls of the first electrically conductive material layers to form metal lines, while not growing from the surfaces of the insulator lines. The metal lines are oxidized to form metal oxide lines that are self-aligned to the sidewalls of the first electrically conductive lines. Vertically extending second electrically conductive lines can be formed as a two-dimensional array of generally pillar-shaped structures between the alternating stacks of the insulator lines and the first electrically conductive lines. Each portion of the metal oxide lines at junctions of first and second electrically conductive lines constitute a resistive memory element for a resistive random access memory (ReRAM) device.Type: ApplicationFiled: September 11, 2015Publication date: March 16, 2017Inventors: Shin KIKUCHI, Kazushi KOMEDA, Takuya FUTASE, Teruyuki MINE, Seje TAKAKI, Eiji HAYASHI, Toshihide TOBITSUKA
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Patent number: 9595566Abstract: A 3D nonvolatile memory has memory elements arranged in a three-dimensional pattern with a plurality of memory layers stacked over a semiconductor substrate. It has a 2D array of vertical bit lines and a plurality of staircase word lines. Each staircase word line has a series of alternating segments and risers and traverses the plurality of memory layers with a segment in each memory layer. The plurality of staircase word lines have their segments lined up to form a 2D array of stacks of segments. Riser for a pair of segments from each adjacent stacks at different memory layers is provided by a conductive sidewall layer of a stairwell disposed between the adjacent stacks. Multiple insulated conductive sidewall layers provide multiple risers for the adjacent stacks. Layer-by-layer stairwell excavation and sidewall processes between adjacent stacks create risers for different pairs of segments between stacks to form the staircase word lines.Type: GrantFiled: February 25, 2015Date of Patent: March 14, 2017Assignee: SanDisk Technologies LLCInventor: Seje Takaki
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Patent number: 9583539Abstract: A three-dimensional monolithic memory device includes at least one device region and a plurality of contact regions each including a stack of an alternating plurality of conductive word line contact layers and insulating layers located over a substrate, where the stacks in the plurality of contact regions are separated from one another by an insulating material, and a bridge connector including a conductive material extending between a first conductive word line contact layer of a first stack in a first contact region and a second conductive word line contact layer of a second stack in a second contact region, where the first word line contact layer extends in a first contact level substantially parallel to a major surface of the substrate and the second word line contact layer extends in a second contact level substantially parallel to the major surface of the substrate that is different than the first level.Type: GrantFiled: August 19, 2014Date of Patent: February 28, 2017Assignee: SANDISK TECHNOLOGIES LLCInventor: Seje Takaki
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Patent number: 9530824Abstract: A monolithic three-dimensional memory array is provided that includes a plurality of global bit lines disposed above a substrate, each global bit line having a long axis, a plurality of vertically-oriented bit lines disposed above the global bit lines, a plurality of word lines disposed above the global bit lines, a plurality of memory cells coupled between the vertically-oriented bit lines and the word lines, and a plurality of vertically-oriented bit line select transistors coupled between the vertically-oriented bit lines and the global bit lines, each vertically-oriented bit line select transistor comprising a width and a thickness. Vertically-oriented bit line select transistors disposed above adjacent global bit lines are offset from one another in a direction along the long axis of the global bit lines. The width of each vertically-oriented bit line select transistor is greater than the thickness of the vertically-oriented bit line select transistors.Type: GrantFiled: November 14, 2014Date of Patent: December 27, 2016Assignee: SanDisk Technologies LLCInventors: Seje Takaki, Yoshio Mori