Patents by Inventor Kei NOZAWA

Kei NOZAWA 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: 20230023523
    Abstract: A three-dimensional memory device includes vertical layer stacks that are laterally spaced apart by backside trenches that laterally extend along a first horizontal direction, where each of the vertical layer stacks includes a respective alternating stack of insulating layers and electrically conductive layers, memory openings vertically extending through the alternating stacks, memory opening fill structures located in the memory openings and including a respective vertical stack of memory elements and a respective vertical semiconductor channel, and backside trench fill structures located within a respective one of the backside trenches. Each of the backside trench fill structures includes a plurality of dielectric bridge structures laterally spaced apart along the first horizontal direction and dielectric fin portions located at levels of a plurality of the electrically conductive layers.
    Type: Application
    Filed: September 29, 2022
    Publication date: January 26, 2023
    Inventors: Hiromi MINAMITANI, Kei NOZAWA, Yusuke YOSHIDA
  • Patent number: 10971514
    Abstract: A multi-tier three-dimensional memory array includes multiple alternating stacks of insulating layers and electrically conductive layers that are vertically stacked. Memory stack structures including memory films and semiconductor channels extend through the alternating stacks. The alternating stacks are formed as alternating stacks of insulating layers and sacrificial material layers, and are subsequently modified by replacing the sacrificial material layers with electrically conductive layers. Structural support during replacement of the sacrificial material layers with the electrically conductive layers is provided by the memory stack structures and dielectric support pillar structures. The dielectric support pillar structures may be formed only for a first-tier structure including a first-tier alternating stack of first insulating layers and first spacer material layers, or may vertically extend over multiple tiers.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: April 6, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yoshitaka Otsu, Kei Nozawa, Yashushi Doda, Naoto Hojo, Yoshinobu Tanaka, Koichi Ito, Zhiwei Chen, Yusuke Ikawa, Takeshi Kawamura, Ryoichi Ehara
  • Patent number: 10957706
    Abstract: A multi-tier three-dimensional memory array includes multiple alternating stacks of insulating layers and electrically conductive layers that are vertically stacked. Memory stack structures including memory films and semiconductor channels extend through the alternating stacks. The alternating stacks are formed as alternating stacks of insulating layers and sacrificial material layers, and are subsequently modified by replacing the sacrificial material layers with electrically conductive layers. Structural support during replacement of the sacrificial material layers with the electrically conductive layers is provided by the memory stack structures and dielectric support pillar structures. The dielectric support pillar structures may be formed only for a first-tier structure including a first-tier alternating stack of first insulating layers and first spacer material layers, or may vertically extend over multiple tiers.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: March 23, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yoshitaka Otsu, Kei Nozawa, Yashushi Doda, Naoto Hojo, Yoshinobu Tanaka, Koichi Ito
  • Patent number: 10879264
    Abstract: An alternating layer stack of insulating layers and sacrificial material layers is formed over a semiconductor substrate, and memory stack structures are formed through the vertically-alternating layer stack. A pair of unconnected barrier trenches or a moat trench is formed through the alternating stack concurrently with formation of backside trenches. Backside recesses are formed by isotropically etching the sacrificial material layers selective to the insulating layers while a dielectric liner covers the barrier trenches or the moat trench. A vertically alternating sequence of the insulating plates and the dielectric spacer plates is provided between the pair of barrier trenches or inside the moat trench. Electrically conductive layers are formed in the backside recesses. A first conductive via structure is formed through the vertically alternating sequence concurrently with formation of a second conductive via structure through a dielectric material portion adjacent to the alternating stack.
    Type: Grant
    Filed: June 18, 2019
    Date of Patent: December 29, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yoshitaka Otsu, Kei Nozawa, Naoto Hojo
  • Publication number: 20200402905
    Abstract: An alternating layer stack of insulating layers and sacrificial material layers is formed over a semiconductor substrate, and memory stack structures are formed through the vertically-alternating layer stack. A pair of unconnected barrier trenches or a moat trench is formed through the alternating stack concurrently with formation of backside trenches. Backside recesses are formed by isotropically etching the sacrificial material layers selective to the insulating layers while a dielectric liner covers the barrier trenches or the moat trench. A vertically alternating sequence of the insulating plates and the dielectric spacer plates is provided between the pair of barrier trenches or inside the moat trench. Electrically conductive layers are formed in the backside recesses. A first conductive via structure is formed through the vertically alternating sequence concurrently with formation of a second conductive via structure through a dielectric material portion adjacent to the alternating stack.
    Type: Application
    Filed: June 18, 2019
    Publication date: December 24, 2020
    Inventors: Yoshitaka OTSU, Kei NOZAWA, Naoto HOJO, Hirofumi TOKITA, Eiji HAYASHI, Masanori TERAHARA
  • Publication number: 20200402992
    Abstract: An alternating layer stack of insulating layers and sacrificial material layers is formed over a semiconductor substrate, and memory stack structures are formed through the vertically-alternating layer stack. A pair of unconnected barrier trenches or a moat trench is formed through the alternating stack concurrently with formation of backside trenches. Backside recesses are formed by isotropically etching the sacrificial material layers selective to the insulating layers while a dielectric liner covers the barrier trenches or the moat trench. A vertically alternating sequence of the insulating plates and the dielectric spacer plates is provided between the pair of barrier trenches or inside the moat trench. Electrically conductive layers are formed in the backside recesses. A first conductive via structure is formed through the vertically alternating sequence concurrently with formation of a second conductive via structure through a dielectric material portion adjacent to the alternating stack.
    Type: Application
    Filed: June 18, 2019
    Publication date: December 24, 2020
    Inventors: Yoshitaka OTSU, Kei NOZAWA, Naoto HOJO
  • Patent number: 10872857
    Abstract: An alternating layer stack of insulating layers and sacrificial material layers is formed over a semiconductor substrate, and memory stack structures are formed through the vertically-alternating layer stack. A pair of unconnected barrier trenches or a moat trench is formed through the alternating stack concurrently with formation of backside trenches. Backside recesses are formed by isotropically etching the sacrificial material layers selective to the insulating layers while a dielectric liner covers the barrier trenches or the moat trench. A vertically alternating sequence of the insulating plates and the dielectric spacer plates is provided between the pair of barrier trenches or inside the moat trench. Electrically conductive layers are formed in the backside recesses. A first conductive via structure is formed through the vertically alternating sequence concurrently with formation of a second conductive via structure through a dielectric material portion adjacent to the alternating stack.
    Type: Grant
    Filed: June 18, 2019
    Date of Patent: December 22, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yoshitaka Otsu, Kei Nozawa, Naoto Hojo, Hirofumi Tokita, Eiji Hayashi, Masanori Terahara
  • Publication number: 20200127005
    Abstract: A multi-tier three-dimensional memory array includes multiple alternating stacks of insulating layers and electrically conductive layers that are vertically stacked. Memory stack structures including memory films and semiconductor channels extend through the alternating stacks. The alternating stacks are formed as alternating stacks of insulating layers and sacrificial material layers, and are subsequently modified by replacing the sacrificial material layers with electrically conductive layers. Structural support during replacement of the sacrificial material layers with the electrically conductive layers is provided by the memory stack structures and dielectric support pillar structures. The dielectric support pillar structures may be formed only for a first-tier structure including a first-tier alternating stack of first insulating layers and first spacer material layers, or may vertically extend over multiple tiers.
    Type: Application
    Filed: February 15, 2019
    Publication date: April 23, 2020
    Inventors: Yoshitaka OTSU, Kei NOZAWA, Yashushi DODA, Naoto HOJO, Yoshinobu TANAKA, Koichi ITO
  • Publication number: 20200127006
    Abstract: A multi-tier three-dimensional memory array includes multiple alternating stacks of insulating layers and electrically conductive layers that are vertically stacked. Memory stack structures including memory films and semiconductor channels extend through the alternating stacks. The alternating stacks are formed as alternating stacks of insulating layers and sacrificial material layers, and are subsequently modified by replacing the sacrificial material layers with electrically conductive layers. Structural support during replacement of the sacrificial material layers with the electrically conductive layers is provided by the memory stack structures and dielectric support pillar structures. The dielectric support pillar structures may be formed only for a first-tier structure including a first-tier alternating stack of first insulating layers and first spacer material layers, or may vertically extend over multiple tiers.
    Type: Application
    Filed: February 15, 2019
    Publication date: April 23, 2020
    Inventors: Yoshitaka OTSU, Kei NOZAWA, Yashushi DODA, Naoto HOJO, Yoshinobu TANAKA, Koichi ITO, Zhiwei CHEN, Yusuke IKAWA, Takeshi KAWAMURA, Ryoichi EHARA
  • Patent number: 9397115
    Abstract: A stack is formed over a substrate, which comprises an alternating plurality of first material layers including a first material and second material layers including a second material. A patterned hard mask is formed, which includes multiple laterally spaced apart strips. A trimming material layer is formed over the hard mask layer. At least one cycle of process steps is subsequent performed, which include etching the first material employing the second material and the trimming material layer as an etch mask, trimming the trimming material layer to expose a strip of the hard mask layer, etching the second material and the exposed strip of the hard mask layer employing the trimming material layer as an etch mask, and trimming the trimming material layer to expose an edge of a next strip of the hard mask layer. Stepped surfaces suitable for formation of contact via array can thus be formed.
    Type: Grant
    Filed: December 29, 2014
    Date of Patent: July 19, 2016
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventor: Kei Nozawa
  • Publication number: 20160190154
    Abstract: A stack is formed over a substrate, which comprises an alternating plurality of first material layers including a first material and second material layers including a second material. A patterned hard mask is formed, which includes multiple laterally spaced apart strips. A trimming material layer is formed over the hard mask layer. At least one cycle of process steps is subsequent performed, which include etching the first material employing the second material and the trimming material layer as an etch mask, trimming the trimming material layer to expose a strip of the hard mask layer, etching the second material and the exposed strip of the hard mask layer employing the trimming material layer as an etch mask, and trimming the trimming material layer to expose an edge of a next strip of the hard mask layer. Stepped surfaces suitable for formation of contact via array can thus be formed.
    Type: Application
    Filed: December 29, 2014
    Publication date: June 30, 2016
    Inventor: Kei NOZAWA