Patents by Inventor Masatoshi Nishikawa

Masatoshi Nishikawa 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).

  • Publication number: 20210035998
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. A memory opening is formed through the alternating stack. An amorphous semiconductor material portion is formed at a bottom region of the memory opening. A memory film is formed in the memory opening. The memory film includes an opening at a bottom portion thereof, and a surface of the amorphous semiconductor material portion is physically exposed at a bottom of the opening in the memory film. An amorphous semiconductor channel material layer is formed on the exposed surface of the amorphous semiconductor material portion and over the memory film. A vertical semiconductor channel is formed by annealing the amorphous semiconductor material portion and the amorphous semiconductor channel material layer. The vertical semiconductor channel and contacts an entire top surface of an underlying semiconductor material portion.
    Type: Application
    Filed: August 30, 2019
    Publication date: February 4, 2021
    Inventors: Masatoshi NISHIKAWA, Jayavel PACHAMUTHU
  • Patent number: 10878907
    Abstract: Systems and methods for reducing the size of sub-blocks within a physical memory block for a three-dimensional non-volatile memory using buried source lines are described. The physical memory block may be fabricated using dual buried source lines such that sub-blocks within the physical memory block may be individually selected in both a horizontal word line direction and a vertical NAND string direction. The physical memory block may include a plurality of sub-blocks that are individually selectable and that share bit lines and/or source-side select gate lines. The plurality of sub-blocks that are individually selectable may correspond with different portions of the same NAND string in which a first sub-block of the plurality of sub-blocks connects to a drain-side select gate for the NAND string and a second sub-block of the plurality of sub-blocks connects to a source-side select gate for the NAND string.
    Type: Grant
    Filed: June 5, 2019
    Date of Patent: December 29, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Hardwell Chibvongodze, Masatoshi Nishikawa
  • Publication number: 20200402990
    Abstract: A first semiconductor die includes a first substrate, first semiconductor devices, first dielectric material layers having a first silicon oxide surface as an uppermost surface and forming first metal interconnect structures. A second semiconductor die includes a second substrate, second semiconductor devices, and second dielectric material layers forming second metal interconnect structures. A handle substrate is attached to a topmost surface of the second semiconductor die. The second substrate is thinned, and a second silicon oxide surface is provided as a bottommost surface of the second semiconductor die. The second semiconductor die is bonded to the first semiconductor die by inducing oxide-to-oxide bonding between the second silicon oxide surface and the first silicon oxide surface. The handle substrate is detached, and inter-die connection via structures are formed through the second substrate and the bonding interface to contact the first metal interconnect structures.
    Type: Application
    Filed: September 1, 2020
    Publication date: December 24, 2020
    Inventors: Masatoshi NISHIKAWA, Akio NISHIDA
  • Publication number: 20200402587
    Abstract: A memory device is disclosed configured to share word line switches (WLSW) between each word line of two adjacent erase blocks. The word lines are driven from both sides of the memory array to reduces resistive-capacitive (RC) loading during pre-charge/ramp-up periods and during discharge/ramp-down periods for various storage operations. The dual-sided driving of signals combines with synergistic erase block size management to lower read latency (tR) for non-volatile memory media.
    Type: Application
    Filed: June 18, 2019
    Publication date: December 24, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Hardwell Chibvongodze, Masatoshi Nishikawa
  • Publication number: 20200395408
    Abstract: A vertically alternating sequence of insulating layers and sacrificial material layers is formed over a substrate. Line trenches extending along a first horizontal direction are formed through the vertically alternating sequence. The vertically alternating sequence is divided into vertically alternating stacks of insulating strips and sacrificial material strips. Laterally alternating sequences of memory opening fill structures and dielectric pillar structures are formed within the line trenches. Each of the memory opening fill structures includes a respective vertical bit line and memory material portion located between each laterally neighboring pair of the sacrificial material strip and the vertical bit line.
    Type: Application
    Filed: June 13, 2019
    Publication date: December 17, 2020
    Inventors: Yuji TAKAHASHI, Masatoshi NISHIKAWA, Wei Kuo SHIH
  • Publication number: 20200395407
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings are formed through the alternating stack. Protruding tip portions are formed on each of the sacrificial material layers around the memory openings. A plurality of insulating spacers is formed within each memory opening between each vertically neighboring pair of tip portions of the sacrificial material layers. A phase change memory material and a vertical bit line are formed within each of the memory openings. The phase change memory material can be formed as a vertical stack of discrete annular phase change memory material portions, or can be formed as a continuous phase change memory material layer. Each of the sacrificial material layer can be replaced by an electrically conductive layer.
    Type: Application
    Filed: June 13, 2019
    Publication date: December 17, 2020
    Inventors: Yuji TAKAHASHI, Masatoshi NISHIKAWA, Wei Kuo SHIH
  • Publication number: 20200388335
    Abstract: Systems and methods for reducing the size of sub-blocks within a physical memory block for a three-dimensional non-volatile memory using buried source lines are described. The physical memory block may be fabricated using dual buried source lines such that sub-blocks within the physical memory block may be individually selected in both a horizontal word line direction and a vertical NAND string direction. The physical memory block may include a plurality of sub-blocks that are individually selectable and that share bit lines and/or source-side select gate lines. The plurality of sub-blocks that are individually selectable may correspond with different portions of the same NAND string in which a first sub-block of the plurality of sub-blocks connects to a drain-side select gate for the NAND string and a second sub-block of the plurality of sub-blocks connects to a source-side select gate for the NAND string.
    Type: Application
    Filed: June 5, 2019
    Publication date: December 10, 2020
    Applicant: SANDISK TECHNOLOGIES LLC
    Inventors: Hardwell Chibvongodze, Masatoshi Nishikawa
  • Patent number: 10854619
    Abstract: A three-dimensional memory device includes memory stack structures in multiple memory arrays. Bit lines are split into multiple portions traversing different memory arrays. Each sense amplifier is connected to a first portion of a respective bit line via a respective first switching transistor device, and is connected to a second portion of the respective bit line via a respective second switching transistor device. The switching transistor devices connect each sense amplifier to one portion of the bit lines without connecting to another portion of the bit lines, thereby reducing the RC delay. The switching transistor devices may be provided as vertical field effect transistors located at a memory array level, or may be provided in another semiconductor chip.
    Type: Grant
    Filed: December 7, 2018
    Date of Patent: December 1, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Hardwell Chibvongodze, Masatoshi Nishikawa, Naoki Ookuma, Takuya Ariki, Toru Miwa
  • Publication number: 20200365210
    Abstract: A semiconductor device is disclosed including an integrated memory module. The integrated memory module includes a first semiconductor die comprising first non-volatile memory cells, a second semiconductor die comprising second non-volatile memory cells, and a third semiconductor die comprising control circuitry. The first, the second and the third semiconductor die are bonded together. The control circuitry is configured to control memory operations in the first memory cells in parallel with the second memory cells.
    Type: Application
    Filed: May 17, 2019
    Publication date: November 19, 2020
    Applicant: SanDisk Technologies LLC
    Inventors: Hardwell Chibvongodze, Masatoshi Nishikawa
  • Patent number: 10839918
    Abstract: Boost converter in memory chip. A non-volatile memory including an in-chip boost converter includes: a first memory structure defines control circuitry disposed on a first substrate, and a first metal layers disposed adjacent the control circuitry, where the first metal layer couples elements of the control circuitry; and a second memory structure defines a memory array disposed on a second substrate, and a second metal layer disposed adjacent the memory array, where the first and second metal layers are bonded together by a permanent physical bond formed between the first and second metal layers; and a boost converter defining an inductor disposed in the first and second metal layers, and a transistor circuit disposed in the control circuitry. The non-volatile memory, where the inductor further defines a first terminal coupled to a voltage source, and a second terminal coupled to a load by way of a transistor circuit.
    Type: Grant
    Filed: June 24, 2019
    Date of Patent: November 17, 2020
    Assignee: SanDisk Technologies LLC
    Inventors: Hardwell Chibvongodze, Masatoshi Nishikawa
  • Publication number: 20200335512
    Abstract: A first semiconductor die includes a first substrate, first semiconductor devices, first dielectric material layers having a first silicon oxide surface as an uppermost surface and forming first metal interconnect structures. A second semiconductor die includes a second substrate, second semiconductor devices, and second dielectric material layers forming second metal interconnect structures. A handle substrate is attached to a topmost surface of the second semiconductor die. The second substrate is thinned, and a second silicon oxide surface is provided as a bottommost surface of the second semiconductor die. The second semiconductor die is bonded to the first semiconductor die by inducing oxide-to-oxide bonding between the second silicon oxide surface and the first silicon oxide surface. The handle substrate is detached, and inter-die connection via structures are formed through the second substrate and the bonding interface to contact the first metal interconnect structures.
    Type: Application
    Filed: April 16, 2019
    Publication date: October 22, 2020
    Inventors: Masatoshi NISHIKAWA, Akio NISHIDA
  • Publication number: 20200335518
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate. The alternating stack includes a first region in which all layers of the alternating stack are present and a second region in which at least a topmost one of the electrically conductive layers is absent. First memory opening fill structures extend through the first region of the alternating stack, and second memory opening fill structures extend through the second region of the alternating stack. The first memory opening fill structures have a greater height than the second memory opening fill structures. Pocket doping regions extending over a respective subset of topmost electrically conductive layers for the memory opening fill structures can be formed to provide higher threshold voltages and to enable selective activation of vertical semiconductor channels connected a same bit line.
    Type: Application
    Filed: July 2, 2020
    Publication date: October 22, 2020
    Inventors: Zhixin Cui, Masatoshi Nishikawa, Ken Oowada
  • Patent number: 10797062
    Abstract: A first semiconductor die includes a first substrate, first semiconductor devices, first dielectric material layers having a first silicon oxide surface as an uppermost surface and forming first metal interconnect structures. A second semiconductor die includes a second substrate, second semiconductor devices, and second dielectric material layers forming second metal interconnect structures. A handle substrate is attached to a topmost surface of the second semiconductor die. The second substrate is thinned, and a second silicon oxide surface is provided as a bottommost surface of the second semiconductor die. The second semiconductor die is bonded to the first semiconductor die by inducing oxide-to-oxide bonding between the second silicon oxide surface and the first silicon oxide surface. The handle substrate is detached, and inter-die connection via structures are formed through the second substrate and the bonding interface to contact the first metal interconnect structures.
    Type: Grant
    Filed: April 16, 2019
    Date of Patent: October 6, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Masatoshi Nishikawa, Akio Nishida
  • Publication number: 20200286915
    Abstract: A three-dimensional memory device includes alternating stacks of electrically conductive strips and spacer strips located over a substrate and laterally spaced apart among one another by memory stack assemblies. The spacer strips may include air gap strips or insulating strips. Each of the memory stack assemblies includes two two-dimensional arrays of lateral protrusion regions. Each of the lateral protrusion regions comprises a respective curved charge storage element. The charge storage elements may be discrete elements located within a respective lateral protrusion region, or may be a portion of a charge storage material layer that extends vertically over multiple electrically conductive strips. Each of the memory stack assemblies may include two rows of vertical semiconductor channels that laterally overlie a respective vertical stack of charge storage elements.
    Type: Application
    Filed: May 20, 2020
    Publication date: September 10, 2020
    Inventors: Zhixin Cui, Masatoshi Nishikawa, Yanli Zhang
  • Publication number: 20200286903
    Abstract: A three-dimensional memory device includes alternating stacks of electrically conductive strips and spacer strips located over a substrate and laterally spaced apart among one another by memory stack assemblies. The spacer strips may include air gap strips or insulating strips. Each of the memory stack assemblies includes two two-dimensional arrays of lateral protrusion regions. Each of the lateral protrusion regions comprises a respective curved charge storage element. The charge storage elements may be discrete elements located within a respective lateral protrusion region, or may be a portion of a charge storage material layer that extends vertically over multiple electrically conductive strips. Each of the memory stack assemblies may include two rows of vertical semiconductor channels that laterally overlie a respective vertical stack of charge storage elements.
    Type: Application
    Filed: May 21, 2020
    Publication date: September 10, 2020
    Inventors: Zhixin Cui, Masatoshi Nishikawa, Yanli Zhang
  • Publication number: 20200279866
    Abstract: A three-dimensional memory device includes alternating stacks of insulating strips and electrically conductive strips located over a substrate and laterally spaced apart among one another by line trenches which laterally extend along a first horizontal direction and are spaced apart along a second horizontal direction, and memory stack structures arranged in rows extending along the first horizontal direction. Each row of memory stack structures is located on a respective sidewall of the line trenches. Each of the memory stack structures includes a vertical semiconductor channel, a tunneling dielectric contacting the vertical semiconductor channel, a charge storage layer contacting the tunneling dielectric, and a composite blocking dielectric. The composite blocking dielectric includes a first dipole-containing blocking dielectric layer stack, a homogeneous blocking dielectric layer, and a second dipole-containing blocking dielectric layer stack.
    Type: Application
    Filed: May 18, 2020
    Publication date: September 3, 2020
    Inventors: Masatoshi NISHIKAWA, Kiyohiko SAKAKIBARA
  • Patent number: 10756106
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers containing word lines and drain select gate electrodes located over a substrate, and memory stack structures containing a respective vertical semiconductor channel and a memory film including a tunneling dielectric and a charge storage layer. A first portion of a first charge storage layer located in a first memory stack structure at level of a first drain select gate electrode is thicker than a first portion of a second charge storage layer located in a second memory stack structure at the level of the first drain select electrode.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: August 25, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Masatoshi Nishikawa, Michiaki Sano, Ken Oowada, Zhixin Cui
  • Publication number: 20200266182
    Abstract: A first memory die includes an array of first memory stack structures and first bit lines. A second memory die includes an array of second memory stack structures and second bit lines electrically connected to a respective subset of the second drain regions. A support die is provided, which includes a peripheral circuitry for operating the array of first memory stack structures and the array of second memory stack structures. The peripheral circuitry includes a plurality of sense amplifiers configured to make switchable electrical connections to a set of bit lines selected from the first bit lines and the second bit lines. The first memory die is bonded to the support die, and the second memory die is bonded to the first memory die. The peripheral circuitry in the support die may be shared between the first memory die and the second memory die.
    Type: Application
    Filed: February 14, 2019
    Publication date: August 20, 2020
    Inventors: Masatoshi NISHIKAWA, Hardwell CHIBVONGODZE
  • Patent number: 10741576
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and word lines located over a substrate, memory stack structures extending through the alternating stack and containing a respective vertical semiconductor channel and a respective memory film, drain select gate electrodes located over the alternating stack, extending along a first horizontal direction, and laterally spaced apart along a second horizontal direction, and a dielectric cap layer located between adjacent drain select gate electrodes. An air gap is located between adjacent drain select gate electrodes in the dielectric cap layer.
    Type: Grant
    Filed: September 20, 2018
    Date of Patent: August 11, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Masatoshi Nishikawa, Akio Nishida
  • Patent number: 10741535
    Abstract: A first memory die includes an array of first memory stack structures and first bit lines. A second memory die includes an array of second memory stack structures and second bit lines electrically connected to a respective subset of the second drain regions. A support die is provided, which includes a peripheral circuitry for operating the array of first memory stack structures and the array of second memory stack structures. The peripheral circuitry includes a plurality of sense amplifiers configured to make switchable electrical connections to a set of bit lines selected from the first bit lines and the second bit lines. The first memory die is bonded to the support die, and the second memory die is bonded to the first memory die. The peripheral circuitry in the support die may be shared between the first memory die and the second memory die.
    Type: Grant
    Filed: February 14, 2019
    Date of Patent: August 11, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Masatoshi Nishikawa, Hardwell Chibvongodze