Patents by Inventor Naohito Yanagida

Naohito Yanagida 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: 9666799
    Abstract: An alternating stack of electrically conductive layers and electrically insulating layers is formed over global bit lines formed on a substrate. The alternating stack is patterned to form a line stack of electrically conductive lines and electrically insulating lines. Trench isolation structures are formed within each trench to define a plurality of memory openings laterally spaced from one another by the line stack in one direction and by trench isolation structures in another direction. The electrically conductive lines are laterally recessed relative to sidewall surfaces of the electrically insulating lines. A read/write memory material is deposited in recesses, and is anisotropically etched so that a top surface of a global bit line is physically exposed at a bottom of each memory opening. An electrically conductive bit line is formed within each memory opening to form a resistive random access memory device.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: May 30, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Naohito Yanagida, Cheng Feng, Michiaki Sano, Akira Nakada, Steven J. Radigan, Eiji Hayashi
  • Patent number: 9620712
    Abstract: An alternating stack of electrically conductive layers and electrically insulating layers is formed over global bit lines formed on a substrate. The alternating stack is patterned to form a line stack of electrically conductive lines and electrically insulating lines. Trench isolation structures are formed within each trench to define a plurality of memory openings laterally spaced from one another by the line stack in one direction and by trench isolation structures in another direction. The electrically conductive lines are laterally recessed relative to sidewall surfaces of the electrically insulating lines. A read/write memory material is deposited in recesses, and is anisotropically etched so that a top surface of a global bit line is physically exposed at a bottom of each memory opening. An electrically conductive bit line is formed within each memory opening to form a resistive random access memory device.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: April 11, 2017
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Eiji Hayashi, Naohito Yanagida, Michiaki Sano, Akira Nakada
  • Patent number: 9401309
    Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.
    Type: Grant
    Filed: August 26, 2014
    Date of Patent: July 26, 2016
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Keisuke Izumi, Naohito Yanagida, Michiaki Sano, Takehiro Yamazaki, Hiroaki Iuchi, Akio Yanai, Genta Mizuno, Minoru Yamaguchi
  • Patent number: 9368601
    Abstract: A fabrication process for a vertical channel transistor provides a desired control gate-to-drain overlap and sufficient isolation between the control gate and an underlying metal line. A body of the transistor is formed on a metal line, such as in a pillar shape. The metal line is oxidized to form metal oxide regions having an expanded volume. A gate insulator material and a control gate material are then deposited. The resulting structure is etched to form separate control gates for each transistor, and to expose the metal oxide. A further etch is performed to remove the metal oxide, forming voids under and around the control gates. An insulation fills the voids. An example implementation is a vertical bit line memory device in which the transistors connect a vertical bit line to a horizontal bit line.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: June 14, 2016
    Assignee: SanDisk Technologies Inc.
    Inventors: Michiaki Sano, Kensuke Yamaguchi, Akira Nakada, Naohito Yanagida
  • Publication number: 20160126455
    Abstract: An alternating stack of electrically conductive layers and electrically insulating layers is formed over global bit lines formed on a substrate. The alternating stack is patterned to form a line stack of electrically conductive lines and electrically insulating lines. Trench isolation structures are formed within each trench to define a plurality of memory openings laterally spaced from one another by the line stack in one direction and by trench isolation structures in another direction. The electrically conductive lines are laterally recessed relative to sidewall surfaces of the electrically insulating lines. A read/write memory material is deposited in recesses, and is anisotropically etched so that a top surface of a global bit line is physically exposed at a bottom of each memory opening. An electrically conductive bit line is formed within each memory opening to form a resistive random access memory device.
    Type: Application
    Filed: October 31, 2014
    Publication date: May 5, 2016
    Inventors: Eiji Hayashi, Naohito Yanagida, Michiaki Sano, Akira Nakada
  • Publication number: 20160126292
    Abstract: An alternating stack of electrically conductive layers and electrically insulating layers is formed over global bit lines formed on a substrate. The alternating stack is patterned to form a line stack of electrically conductive lines and electrically insulating lines. Trench isolation structures are formed within each trench to define a plurality of memory openings laterally spaced from one another by the line stack in one direction and by trench isolation structures in another direction. The electrically conductive lines are laterally recessed relative to sidewall surfaces of the electrically insulating lines. A read/write memory material is deposited in recesses, and is anisotropically etched so that a top surface of a global bit line is physically exposed at a bottom of each memory opening. An electrically conductive bit line is formed within each memory opening to form a resistive random access memory device.
    Type: Application
    Filed: October 31, 2014
    Publication date: May 5, 2016
    Inventors: Naohito Yanagida, Cheng Feng, Michiaki Sano, Akira Nakada, Steven J. Radigan, Eiji Hayashi
  • Publication number: 20160064281
    Abstract: Contact openings extending to sacrificial layers located at different depths can be formed by sequentially exposing a greater number of openings in a mask layer by iterative alternation of trimming of a slimming layer over the mask layer and an anisotropic etch that recesses pre-existing contact openings by one level. In one embodiment, pairs of an electrically conductive via contact and electrically conductive electrodes can be simultaneously formed as integrated line and via structures. In another embodiment, encapsulated unfilled cavities can be formed in the contact openings by non-conformal deposition of a material layer, electrically conductive electrodes can be formed by replacement of portions of the sacrificial layers, and the electrically conductive via contacts can be subsequently formed on the electrically conductive electrodes. Electrically conductive via contacts extending to electrically conductive electrodes located at different level can be provided with self-aligned insulating liner.
    Type: Application
    Filed: August 26, 2014
    Publication date: March 3, 2016
    Inventors: Keisuke Izumi, Naohito Yanagida, Michiaki Sano, Takehiro Yamazaki, Hiroaki Iuchi, Akio Yanai, Genta Mizuno, Minoru Yamaguchi
  • Patent number: 9177964
    Abstract: A method of forming sidewall gates for vertical transistors includes depositing a gate dielectric layer over polysilicon channel structures, and depositing a gate polysilicon layer over the gate dielectric. The gate polysilicon layer is then etched back to form separated gate electrodes. Filler portions are then formed between gate electrodes, which are then etched from the top down while their sides are protected.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: November 3, 2015
    Assignee: SanDisk 3D LLC
    Inventors: Akira Nakada, Michiaki Sano, Naohito Yanagida, Teruyuki Mine
  • Publication number: 20150249143
    Abstract: A fabrication process for a vertical channel transistor provides a desired control gate-to-drain overlap and sufficient isolation between the control gate and an underlying metal line. A body of the transistor is formed on a metal line, such as in a pillar shape. The metal line is oxidized to form metal oxide regions having an expanded volume. A gate insulator material and a control gate material are then deposited. The resulting structure is etched to form separate control gates for each transistor, and to expose the metal oxide. A further etch is performed to remove the metal oxide, forming voids under and around the control gates. An insulation fills the voids. An example implementation is a vertical bit line memory device in which the transistors connect a vertical bit line to a horizontal bit line.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 3, 2015
    Applicant: SanDisk 3D LLC
    Inventors: Michiaki Sano, Kensuke Yamaguchi, Akira Nakada, Naohito Yanagida
  • Publication number: 20150162338
    Abstract: A method of forming sidewall gates for vertical transistors includes depositing a gate dielectric layer over polysilicon channel structures, and depositing a gate polysilicon layer over the gate dielectric. The gate polysilicon layer is then etched back to form separated gate electrodes. Filler portions are then formed between gate electrodes, which are then etched from the top down while their sides are protected.
    Type: Application
    Filed: December 6, 2013
    Publication date: June 11, 2015
    Applicant: SanDisk 3D LLC
    Inventors: Akira Nakada, Michiaki Sano, Naohito Yanagida, Teruyuki Mine
  • Patent number: 8609549
    Abstract: A plasma etching method is provided to perform a plasma etching on a silicon oxide film or a silicon nitride film formed below an amorphous carbon film by using a pattern of the amorphous carbon film as a final mask in a multilayer mask including a photoresist layer having a predetermined pattern, an organic bottom anti-reflection coating (BARC) film formed below the photoresist layer, an SiON film formed below the BARC film, and the amorphous carbon film formed below the SiON film. An initial mask used at the time when the plasma etching of the silicon oxide film or the silicon nitride film is started is under a state in which the SiON film remains on the amorphous carbon film and a ratio of a film thickness of the amorphous carbon film to a film thickness of the residual SiON film is smaller than or equal to about 14.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: December 17, 2013
    Assignee: Tokyo Electron Limited
    Inventors: Sungtae Lee, Masahiro Ogasawara, Junichi Sasaki, Naohito Yanagida
  • Publication number: 20110250761
    Abstract: A plasma etching method is provided to perform a plasma etching on a silicon oxide film or a silicon nitride film formed below an amorphous carbon film by using a pattern of the amorphous carbon film as a final mask in a multilayer mask including a photoresist layer having a predetermined pattern, an organic bottom anti-reflection coating (BARC) film formed below the photoresist layer, an SiON film formed below the BARC film, and the amorphous carbon film formed below the SiON film. An initial mask used at the time when the plasma etching of the silicon oxide film or the silicon nitride film is started is under a state in which the SiON film remains on the amorphous carbon film and a ratio of a film thickness of the amorphous carbon film to a film thickness of the residual SiON film is smaller than or equal to about 14.
    Type: Application
    Filed: March 11, 2011
    Publication date: October 13, 2011
    Applicant: TOKYO ELECTRON LIMITED
    Inventors: Sungtae LEE, Masahiro Ogasawara, Junichi Sasaki, Naohito Yanagida