Patents by Inventor Tomoyasu Kakegawa

Tomoyasu Kakegawa 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).

  • Patent number: 10115459
    Abstract: An opening is formed through at least one dielectric material layer. A first metallic liner is formed on a bottom surface and sidewalls of the opening by depositing a first metallic material. A metal portion including an elemental metal or an intermetallic alloy of at least two elemental metals is formed on the first metallic liner. A second metallic liner including a second metallic material is formed directly on a top surface of the metal portion. The first metallic material and the second metallic material differ in composition. The first metallic liner and the second metallic liner contact an entirety of all surfaces of the metal portion. The first and second metallic liners can protect the metal portion from a subsequently deposited dielectric material layer, which may be formed as an air-gap dielectric layer after recessing the at least one dielectric material layer.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: October 30, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Katsuo Yamada, Tomoyasu Kakegawa, Peter Rabkin, Jayavel Pachamuthu, Mohan Dunga, Masaaki Higashitani
  • Patent number: 9847249
    Abstract: A stack of layers is formed that includes first, second, and third dielectric layers. Contact plugs are then formed extending through the stack. Then a fourth dielectric layer is formed over the stack and contact plugs and trenches are formed through the fourth and third dielectric layers, extending to the second dielectric layer and exposing contact plugs.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: December 19, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yuji Takahashi, Takuya Futase, Noritaka Fukuo, Katsuo Yamada, Tomoyasu Kakegawa
  • Patent number: 9799527
    Abstract: Isolation is provided by forming a first trench, depositing a cover layer on the bottom and sidewalls of the first trench, selectively removing the cover layer from the bottom and forming a second trench extending from the bottom of the first trench. The second trench is then substantially filled by thermal oxide formed by oxidation and the first trench is subsequently filled with a deposited dielectric.
    Type: Grant
    Filed: October 21, 2014
    Date of Patent: October 24, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Katsuo Yamada, Yuji Takahashi, Takuya Futase, Noritaka Fukuo, Tomoyasu Kakegawa
  • Patent number: 9768183
    Abstract: An initial etch forms a trench over first contact areas of a plurality of NAND strings, the initial etch also forming individual openings over second contact areas of the plurality of NAND strings. Material is added in the trench to reduce an area of exposed bottom surface of the trench while maintaining the individual openings without substantial reduction of bottom surface area. Subsequent further etching extends the trench and the plurality of individual openings.
    Type: Grant
    Filed: May 15, 2015
    Date of Patent: September 19, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Shunsuke Akimoto, Hidetoshi Nakamoto, Keita Kumamoto, Hidehito Koseki, Yuji Takahashi, Noritaka Fukuo, Tomoyasu Kakegawa, Takuya Futase
  • Publication number: 20170040333
    Abstract: A NAND flash memory includes active areas separated by STI structures in a substrate with a layer of a first dielectric over the substrate. Portions of a second dielectric extend over the STI structures and another layer of the first dielectric extends over both the layer and portions, with contact holes extending through the dielectric layers at locations over the active areas in the semiconductor substrate.
    Type: Application
    Filed: August 3, 2015
    Publication date: February 9, 2017
    Inventors: Keita Kumamoto, Yuji Takahashi, Hidetoshi Nakamoto, Tomoyasu Kakegawa, Shunsuke Akimoto, Hidehito Koseki, Takuya Futase
  • Publication number: 20160336335
    Abstract: An initial etch forms a trench over first contact areas of a plurality of NAND strings, the initial etch also forming individual openings over second contact areas of the plurality of NAND strings. Material is added in the trench to reduce an area of exposed bottom surface of the trench while maintaining the individual openings without substantial reduction of bottom surface area. Subsequent further etching extends the trench and the plurality of individual openings.
    Type: Application
    Filed: May 15, 2015
    Publication date: November 17, 2016
    Inventors: Shunsuke Akimoto, Hidetoshi Nakamoto, Keita Kumamoto, Hidehito Koseki, Yuji Takahashi, Noritaka Fukuo, Tomoyasu Kakegawa, Takuya Futase
  • Patent number: 9466523
    Abstract: Contact holes are constrained to their designated active areas by etch-resistant walls so that they cannot contact adjacent active areas. Etch-resistant walls provide outer limits for any contact hole bending that may occur and thus keep contact holes substantially vertical. Mask openings for contact hole formation may be large so that they overlap etch-resistant walls.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: October 11, 2016
    Assignee: SanDisk Technologies LLC
    Inventors: Tomoyasu Kakegawa, Takuya Futase, Katsuo Yamada, Keita Kumamoto, Hirotada Tobita
  • Publication number: 20160204059
    Abstract: Trenches are formed partially through a sacrificial layer at locations where bit lines are to be formed with some sacrificial material overlying vias. The trenches are lined with a protective layer and then the trenches are extended to expose vias. Bit lines are formed. Then sacrificial material is removed from between bit lines while portions of the protective layer remain to protect the bit lines.
    Type: Application
    Filed: January 9, 2015
    Publication date: July 14, 2016
    Inventors: Noritaka Fukuo, Takuya Futase, Katsuo Yamada, Yuji Takahashi, Tomoyasu Kakegawa
  • Publication number: 20160126179
    Abstract: A stack of layers is formed that includes first, second, and third dielectric layers. Contact plugs are then formed extending through the stack. Then a fourth dielectric layer is formed over the stack and contact plugs and trenches are formed through the fourth and third dielectric layers, extending to the second dielectric layer and exposing contact plugs.
    Type: Application
    Filed: November 5, 2014
    Publication date: May 5, 2016
    Inventors: Yuji Takahashi, Takuya Futase, Noritaka Fukuo, Katsuo Yamada, Tomoyasu Kakegawa
  • Publication number: 20160111493
    Abstract: Isolation is provided by forming a first trench, depositing a cover layer on the bottom and sidewalls of the first trench, selectively removing the cover layer from the bottom and forming a second trench extending from the bottom of the first trench. The second trench is then substantially filled by thermal oxide formed by oxidation and the first trench is subsequently filled with a deposited dielectric.
    Type: Application
    Filed: October 21, 2014
    Publication date: April 21, 2016
    Inventors: Katsuo Yamada, Yuji Takahashi, Takuya Futase, Noritaka Fukuo, Tomoyasu Kakegawa
  • Publication number: 20160035738
    Abstract: Contact holes are constrained to their designated active areas by etch-resistant walls so that they cannot contact adjacent active areas. Etch-resistant walls provide outer limits for any contact hole bending that may occur and thus keep contact holes substantially vertical. Mask openings for contact hole formation may be large so that they overlap etch-resistant walls.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 4, 2016
    Inventors: Tomoyasu Kakegawa, Takuya Futase, Katsuo Yamada, Keita Kumamoto, Hirotada Tobita
  • Publication number: 20150332953
    Abstract: Air gaps are formed between conductive metal lines that have an inner barrier layer and an outer barrier layer. An etch step to remove sacrificial material is performed under a first set of process conditions producing a byproduct that suppresses further etching. A byproduct removal step performed under a second set of process conditions removes the byproduct.
    Type: Application
    Filed: September 25, 2014
    Publication date: November 19, 2015
    Inventors: Takuya Futase, Katsuo Yamada, Tomoyasu Kakegawa, Noritaka Fukuo, Yuji Takahashi
  • Patent number: 9177853
    Abstract: Air gaps are formed between conductive metal lines that have an inner barrier layer and an outer barrier layer. An etch step to remove sacrificial material is performed under a first set of process conditions producing a byproduct that suppresses further etching. A byproduct removal step performed under a second set of process conditions removes the byproduct.
    Type: Grant
    Filed: September 25, 2014
    Date of Patent: November 3, 2015
    Assignee: SanDisk Technologies Inc.
    Inventors: Takuya Futase, Katsuo Yamada, Tomoyasu Kakegawa, Noritaka Fukuo, Yuji Takahashi
  • Publication number: 20140021428
    Abstract: A semiconductor device comprises a first transistor including a first diffusion region, a first body region, and a second diffusion region, formed to align in a direction orthogonal to a main surface; a second transistor including a third diffusion region, a second body region, and a fourth diffusion region, formed to align in a direction orthogonal to the main surface; a first variable resistance element provided in the second diffusion region of the first transistor; a second variable resistance element provided in the fourth diffusion region of the second transistor; a bit line commonly connected to the first variable resistance element and the second variable resistance element; a first word line arranged on a first side of the first body region; a second word line arrange between a second side of the first body region and a first side of the second body region; and a third word line arranged on a second side of the second body region.
    Type: Application
    Filed: July 17, 2013
    Publication date: January 23, 2014
    Inventors: Tomoyasu KAKEGAWA, Takao Adachi, Yoshinori Tanaka
  • Patent number: 8574996
    Abstract: A method of manufacturing a semiconductor device comprises: forming a processing target; forming a first supporter on the processing target; forming a first mask so as to contact one side surface of the first mask with a side surface of the first supporter; patterning the processing target using, as masks, the first mask and the first supporter; forming a second supporter so as to be contacted with a side surface of the processing target exposed in first processing step and the other side surface of the first mask; removing the first supporter; and patterning the processing target using, as masks, the first mask and the second supporter.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: November 5, 2013
    Assignee: Elpida Memory, Inc.
    Inventor: Tomoyasu Kakegawa
  • Patent number: 8513638
    Abstract: A semiconductor device may include, but is not limited to: a first insulating film; a second insulating film over the first insulating film; a first memory structure between the first and second insulating films; and a third insulating film between the first and second insulating films. The first memory structure may include, but is not limited to: a heater electrode; and a phase-change memory element between the heater electrode and the second insulating film. The phase-change memory element contacts the heater electrode. The third insulating film covers at least a side surface of the phase-change memory element. Empty space is positioned adjacent to at least one of the heater electrode and the third insulating film.
    Type: Grant
    Filed: September 2, 2011
    Date of Patent: August 20, 2013
    Assignee: Elpida Memory, Inc.
    Inventors: Tomoyasu Kakegawa, Isamu Asano, Tsuyoshi Kawagoe, Hiromi Sasaoka, Naoya Higano, Yuta Watanabe
  • Publication number: 20130005113
    Abstract: A method of manufacturing a semiconductor device comprises: forming a processing target; forming a first supporter on the processing target; forming a first mask so as to contact one side surface of the first mask with a side surface of the first supporter; patterning the processing target using, as masks, the first mask and the first supporter; forming a second supporter so as to be contacted with a side surface of the processing target exposed in first processing step and the other side surface of the first mask; removing the first supporter; and patterning the processing target using, as masks, the first mask and the second supporter.
    Type: Application
    Filed: June 26, 2012
    Publication date: January 3, 2013
    Applicant: Elpida Memory, Inc.
    Inventor: Tomoyasu KAKEGAWA
  • Publication number: 20120256152
    Abstract: A method for manufacturing a semiconductor device includes: forming a first insulating film that covers a substrate; forming a conductive plug that penetrates the first insulating film; forming a hole portion on the conductive plug by partly removing upper part of the conductive plug, wherein the hole portion has a top surface of the conductive plug as a bottom surface, and has the first insulating film of a portion that covered the partly removed conductive plug as a sidewall; forming a sidewall insulating film that exposes a part of the bottom surface of the hole portion while covering the sidewall of the hole portion and a bottom portion of the hole portion; forming a variable resistance film that covers the sidewall insulating film and the bottom surface of the hole portion; and forming a conductive film that covers the variable resistance film.
    Type: Application
    Filed: April 6, 2012
    Publication date: October 11, 2012
    Applicant: ELPIDA MEMORY, INC.
    Inventor: Tomoyasu KAKEGAWA
  • Publication number: 20120056148
    Abstract: A semiconductor device may include, but is not limited to: a first insulating film; a second insulating film over the first insulating film; a first memory structure between the first and second insulating films; and a third insulating film between the first and second insulating films. The first memory structure may include, but is not limited to: a heater electrode; and a phase-change memory element between the heater electrode and the second insulating film. The phase-change memory element contacts the heater electrode. The third insulating film covers at least a side surface of the phase-change memory element. Empty space is positioned adjacent to at least one of the heater electrode and the third insulating film.
    Type: Application
    Filed: September 2, 2011
    Publication date: March 8, 2012
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Tomoyasu Kakegawa, Isamu Asano, Tsuyoshi Kawagoe, Hiromi Sasaoka, Naoya Higano, Yuta Watanabe
  • Patent number: RE45580
    Abstract: A phase-change nonvolatile memory (PRAM) is constituted of a semiconductor substrate, a lower electrode, a first interlayer insulating film having a first hole, an impurity diffusion layer embedded in the first hole, a second interlayer insulating film having a second hole whose diameter is smaller than the diameter of the first hole, a phase-change recording layer, and an upper electrode. The impurity diffusion layer is constituted of two semiconductor layers having different conductivity types, wherein one semiconductor layer is constituted of a base portion and a projecting portion having a heating spot in contact with the phase-change recording layer, while the other semiconductor layer is formed to surround the projecting portion. A depletion layer is formed in proximity to the junction surface so as to reduce the diameter of the heating spot, thus reducing the current value Ireset for writing data in to the phase-change recording layer.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: June 23, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Tomoyasu Kakegawa