Patents by Inventor Zhixin Cui

Zhixin Cui 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: 20220045091
    Abstract: A three-dimensional memory device includes a source contact layer overlying a substrate, an alternating stack of insulating layers and electrically conductive layers located overlying the source contact layer, and a memory opening fill structure located within a memory opening extending through the alternating stack and the source contact layer. The memory opening fill structure includes a composite semiconductor channel and a memory film laterally surrounding the composite semiconductor channel. The composite semiconductor channel includes a pedestal channel portion having controlled distribution of n-type dopants that diffuse from the source contact layer with a lower diffusion rate provided by carbon doping and smaller grain sizes, or has arsenic doping providing limited diffusion into the vertical semiconductor channel.
    Type: Application
    Filed: August 5, 2020
    Publication date: February 10, 2022
    Inventors: Zhixin CUI, Satoshi SHIMIZU, Yanli ZHANG
  • Publication number: 20220045092
    Abstract: A three-dimensional memory device includes a source contact layer overlying a substrate, an alternating stack of insulating layers and electrically conductive layers located overlying the source contact layer, and a memory opening fill structure located within a memory opening extending through the alternating stack and the source contact layer. The memory opening fill structure includes a composite semiconductor channel and a memory film laterally surrounding the composite semiconductor channel. The composite semiconductor channel includes a pedestal channel portion having controlled distribution of n-type dopants that diffuse from the source contact layer with a lower diffusion rate provided by carbon doping and smaller grain sizes, or has arsenic doping providing limited diffusion into the vertical semiconductor channel.
    Type: Application
    Filed: August 5, 2020
    Publication date: February 10, 2022
    Inventors: Zhixin CUI, Satoshi SHIMIZU, Yanli ZHANG
  • Patent number: 11244958
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory stack structures are formed through the alternating stack. Drain-select-level trenches through an upper subset of the sacrificial material layers, and backside trenches are formed through each layer of the alternating stack. Backside recesses are formed by removing the sacrificial material layers. A first electrically conductive material and a second electrically conductive material are sequentially deposited in the backside recesses and the drain-select-level trenches. Portions of the second electrically conductive material and the first electrically conductive material may be removed by at least one anisotropic etch process from the drain-select-level trenches to provide drain-select-level electrically conductive layers as multiple groups that are laterally spaced apart and electrically isolated from one another by cavities within the drain-select-level trenches.
    Type: Grant
    Filed: May 29, 2020
    Date of Patent: February 8, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Fei Zhou, Raghuveer S. Makala
  • Patent number: 11222954
    Abstract: A three-dimensional memory device includes an alternating stack of word-line-isolation insulating layers and word-line-level electrically conductive layers located over a substrate, a plurality of drain-select-level electrodes that are laterally spaced apart from each other overlying the alternating stack, memory stack structures containing a respective vertical semiconductor channel laterally surrounded by a respective memory film and vertically extending through the alternating stack and the plurality of drain-select-level electrodes, inter-select-gate electrodes located between a respective neighboring pair of the drain-select-level electrodes, and inter-select-gate dielectrics located between each of the inter-select-gate electrodes and a neighboring one of the drain-select-level electrodes. The inter-select-gate electrodes are not electrically connected to the drain-select-level electrodes.
    Type: Grant
    Filed: March 24, 2020
    Date of Patent: January 11, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Hardwell Chibvongodze, Masatoshi Nishikawa
  • Publication number: 20210375847
    Abstract: Multiple bonded units are provided, each of which includes a respective front-side die and a backside die. The two dies in each bonded unit may be a memory die and a logic die configured to control operation of memory elements in the memory die. Alternatively, the two dies may be memory dies. The multiple bonded units can be attached such that front-side external bonding pads have physically exposed surfaces that face upward and backside external bonding pads of each bonded unit have physically exposed surfaces that face downward. A first set of bonding wires can connect a respective pair of front-side external bonding pads, and a second set of bonding wires can connect a respective pair of backside external bonding pads.
    Type: Application
    Filed: May 28, 2020
    Publication date: December 2, 2021
    Inventors: Hardwell CHIBVONGODZE, Zhixin CUI, Rajdeep GAUTAM
  • Publication number: 20210366808
    Abstract: A first-tier structure includes a first vertically alternating sequence of first continuous insulating layers and first continuous sacrificial material layers and a first-tier retro-stepped dielectric material portion overlying first stepped surfaces of the first vertically alternating sequence. A second vertically alternating sequence of second continuous insulating layers and second continuous sacrificial material layers is formed over the first-tier structure. Retro-stepped dielectric material portions are formed in each of the first-tier structure and the second-tier structure. After formation of memory stack structures, electrically conductive layers replace portions of the first and second continuous sacrificial material layers. Laterally-isolated contact via structures can be formed through the second-tier structure and a first-tier retro-stepped dielectric material portion on first electrically conductive layers in the first-tier structure.
    Type: Application
    Filed: July 6, 2020
    Publication date: November 25, 2021
    Inventors: Zhixin CUI, Hirofumi TOKITA
  • Publication number: 20210305384
    Abstract: A three-dimensional memory device includes an alternating stack of word-line-isolation insulating layers and word-line-level electrically conductive layers located over a substrate, a plurality of drain-select-level electrodes that are laterally spaced apart from each other overlying the alternating stack, memory stack structures containing a respective vertical semiconductor channel laterally surrounded by a respective memory film and vertically extending through the alternating stack and the plurality of drain-select-level electrodes, inter-select-gate electrodes located between a respective neighboring pair of the drain-select-level electrodes, and inter-select-gate dielectrics located between each of the inter-select-gate electrodes and a neighboring one of the drain-select-level electrodes. The inter-select-gate electrodes are not electrically connected to the drain-select-level electrodes.
    Type: Application
    Filed: March 24, 2020
    Publication date: September 30, 2021
    Inventors: Zhixin CUI, Hardwell CHIBVONGODZE, Masatoshi NISHIKAWA
  • Patent number: 11114462
    Abstract: A memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, and a memory stack structure extending through the alternating stack. The memory stack structure includes a composite charge storage structure, a tunneling dielectric layer, and a vertical semiconductor channel. The composite charge storage structure may include a vertical stack of tubular charge storage material portions including a first charge trapping material located at levels of the electrically conductive layers, and a charge storage layer including a second charge trapping material extending through a plurality of electrically conductive layers of the electrically conductive layers. The first charge trapping material has a higher charge trap density than the second charge trapping material. Alternatively, the composite charge storage material portions may include discrete charge storage elements each containing a silicon nitride portion and a silicon carbide nitride liner.
    Type: Grant
    Filed: February 19, 2020
    Date of Patent: September 7, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Ippei Yasuda
  • Publication number: 20210257379
    Abstract: A memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, and a memory stack structure extending through the alternating stack. The memory stack structure includes a composite charge storage structure, a tunneling dielectric layer, and a vertical semiconductor channel. The composite charge storage structure may include a vertical stack of tubular charge storage material portions including a first charge trapping material located at levels of the electrically conductive layers, and a charge storage layer including a second charge trapping material extending through a plurality of electrically conductive layers of the electrically conductive layers. The first charge trapping material has a higher charge trap density than the second charge trapping material. Alternatively, the composite charge storage material portions may include discrete charge storage elements each containing a silicon nitride portion and a silicon carbide nitride liner.
    Type: Application
    Filed: February 19, 2020
    Publication date: August 19, 2021
    Inventors: Zhixin CUI, Ippei YASUDA
  • Patent number: 11094715
    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: Grant
    Filed: July 2, 2020
    Date of Patent: August 17, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Masatoshi Nishikawa, Ken Oowada
  • Patent number: 11069703
    Abstract: A memory die including a three-dimensional array of memory elements and a logic die including a peripheral circuitry that support operation of the three-dimensional array of memory elements can be bonded by die-to-die bonding to provide a bonded assembly. External bonding pads for the bonded assembly can be provided by forming recess regions through the memory die or through the logic die to physically expose metal interconnect structures within interconnect-level dielectric layers. The external bonding pads can include, or can be formed upon, a physically exposed subset of the metal interconnect structures. Alternatively or additionally, laterally-insulated external connection via structures can be formed through the bonded assembly to multiple levels of the metal interconnect structures. Further, through-dielectric external connection via structures extending through a stepped dielectric material portion of the memory die can be physically exposed, and external bonding pads can be formed thereupon.
    Type: Grant
    Filed: March 4, 2019
    Date of Patent: July 20, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Akio Nishida, Mitsuteru Mushiga, Zhixin Cui
  • Patent number: 11069410
    Abstract: First alternating stacks of first insulating strips and first spacer material strips is formed in a first device region, second alternating stacks of second insulating strips and second spacer material strips are formed in a second device region. Each of the first line trenches is filled with a respective laterally alternating sequence of memory stack structures and first dielectric pillar structures to form a three-dimensional NAND memory. Each of the memory stack structures includes a vertical semiconductor channel and a vertical stack of memory elements. Each of the second line trenches with a respective laterally alternating sequence of active region assemblies of lateral field effect transistors and second dielectric pillar structures to form a three-dimensional NOR memory. Each of the active region assemblies includes a source pillar, a drain pillar, and a tubular channel region. The spacer material strips include, or are subsequently replaced with, electrically conductive strips.
    Type: Grant
    Filed: August 5, 2020
    Date of Patent: July 20, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Hardwell Chibvongodze, Rajdeep Gautam
  • Patent number: 11049876
    Abstract: A contact via structure vertically extending through an alternating stack of insulating layers and electrically conductive layers is provided in a staircase region having stepped surfaces. The contact via structure is electrically isolated from each electrically conductive layer of the alternating stack except for an electrically conductive layer that directly underlies a horizontal interface of the stepped surfaces.
    Type: Grant
    Filed: May 22, 2020
    Date of Patent: June 29, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Michimoto Kaminaga, Zhixin Cui
  • Patent number: 11024635
    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: Grant
    Filed: May 21, 2020
    Date of Patent: June 1, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Masatoshi Nishikawa, Yanli Zhang
  • Publication number: 20210066347
    Abstract: A joint level dielectric material layer is formed over a first alternating stack of first insulating layers and first spacer material layers. A first memory opening is formed with a tapered sidewall of the joint level dielectric material layer. A second alternating stack of second insulating layers and second spacer material layers is formed over the joint level dielectric material layer. An inter-tier memory opening is formed, which includes a volume of an second memory opening that extends through the second alternating stack and a volume of the first memory opening. A memory film and a semiconductor channel are formed in the inter-tier memory opening with respective tapered portions overlying the tapered sidewall of the joint level dielectric material layer.
    Type: Application
    Filed: November 16, 2020
    Publication date: March 4, 2021
    Inventors: Monica Titus, Zhixin Cui, Senaka Kanakamedala, Yao-Sheng Lee, Chih-Yu Lee
  • Patent number: 10930674
    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: Grant
    Filed: May 20, 2020
    Date of Patent: February 23, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Masatoshi Nishikawa, Yanli Zhang
  • Patent number: 10903230
    Abstract: A contact via structure vertically extending through an alternating stack of insulating layers and electrically conductive layers is provided in a staircase region having stepped surfaces. The contact via structure is electrically isolated from each electrically conductive layer of the alternating stack except for an electrically conductive layer that directly underlies a horizontal interface of the stepped surfaces.
    Type: Grant
    Filed: November 6, 2018
    Date of Patent: January 26, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Michimoto Kaminaga, Zhixin Cui
  • Patent number: 10903222
    Abstract: A three-dimensional memory device includes source-level material layers located over a substrate and including a lower semiconductor layer, a source contact layer, and an upper semiconductor layer. The lower semiconductor layer includes a first boron-doped semiconductor material, the upper semiconductor layer includes carbon doped second boron-doped semiconductor material, and the source contact layer includes a boron-doped semiconductor material. An alternating stack of insulating layers and electrically conductive layers is located over the source-level material layers. Memory stack structures vertically extend through the alternating stack, the upper semiconductor layer, and the source contact layer. Each of the memory stack structures includes a respective memory film and a respective vertical semiconductor channel that contacts the source contact layer.
    Type: Grant
    Filed: May 10, 2019
    Date of Patent: January 26, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Kiyohiko Sakakibara, Masaaki Higashitani, Masanori Tsutsumi, Zhixin Cui
  • Patent number: 10818542
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory stack structures are formed through the alternating stack. Drain-select-level trenches through an upper subset of the sacrificial material layers, and backside trenches are formed through each layer of the alternating stack. Backside recesses are formed by removing the sacrificial material layers. A first electrically conductive material and a second electrically conductive material are sequentially deposited in the backside recesses and the drain-select-level trenches. Portions of the second electrically conductive material and the first electrically conductive material may be removed by at least one anisotropic etch process from the drain-select-level trenches to provide drain-select-level electrically conductive layers as multiple groups that are laterally spaced apart and electrically isolated from one another by cavities within the drain-select-level trenches.
    Type: Grant
    Filed: March 25, 2019
    Date of Patent: October 27, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Zhixin Cui, Fei Zhou, Raghuveer S. Makala
  • 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