Patents by Inventor Naoto NORIZUKI

Naoto NORIZUKI 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: 11792986
    Abstract: A vertical repetition of a unit layer stack includes an insulating layer, a first sacrificial material layer, another insulating layer, and a second sacrificial material layer. A memory opening is formed through the vertical repetition, and a memory opening fill structure is formed in the memory opening. A backside trench is formed through the alternating stack. The first sacrificial material layers are replaced with first electrically conductive layers, and the second sacrificial material layer are replaced with second electrically conductive layers after formation of the first electrically conductive layers.
    Type: Grant
    Filed: April 19, 2021
    Date of Patent: October 17, 2023
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Keigo Kitazawa, Naoto Norizuki, Shunsuke Takuma
  • Publication number: 20220336486
    Abstract: A vertical repetition of a unit layer stack includes an insulating layer, a first sacrificial material layer, another insulating layer, and a second sacrificial material layer. A memory opening is formed through the vertical repetition, and a memory opening fill structure is formed in the memory opening. A backside trench is formed through the alternating stack. The first sacrificial material layers are replaced with first electrically conductive layers, and the second sacrificial material layer are replaced with second electrically conductive layers after formation of the first electrically conductive layers.
    Type: Application
    Filed: April 19, 2021
    Publication date: October 20, 2022
    Inventors: Keigo KITAZAWA, Naoto NORIZUKI, Shunsuke TAKUMA
  • Patent number: 10381373
    Abstract: A method of forming a three-dimensional memory device includes forming at the least one lower level dielectric layer over a semiconductor substrate, forming a buried source line over the least one lower level dielectric layer and over the semiconductor substrate, such that the buried source line is electrically connected to the semiconductor substrate, forming an alternating stack of insulating layers and sacrificial material layers over the buried source line, such that the sacrificial material layers are subsequently replaced with, electrically conductive layers, forming memory openings through the alternating stack by etching through the alternating stack after the buried source line is electrically connected to the semiconductor substrate, and forming memory stack structures in the memory openings. Each memory stack structure includes a vertical semiconductor channel electrically connected to the buried source line and a memory film laterally surrounding the vertical semiconductor channel.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: August 13, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yasuchika Okizumi, Michiru Hirayama, Naoto Norizuki, Satoshi Shimizu, Yasuo Kasagi, Kimiaki Naruse
  • Publication number: 20190043830
    Abstract: A three-dimensional memory device includes a p-doped source semiconductor layer located over a substrate, a p-doped strap semiconductor layer located over the p-doped source semiconductor layer, an alternating stack of electrically conductive layers and insulating layers located over the p-doped strap semiconductor layer, and memory stack structures that extend through the alternating stack and into an upper portion of the p-doped source semiconductor layer. Each memory stack structure includes a p-doped vertical semiconductor channel and a memory film laterally surrounding the p-doped vertical semiconductor channel. A top surface of each p-doped vertical semiconductor channel contacts a bottom surface of a respective n-doped region. A sidewall of a bottom portion of each p-doped vertical semiconductor channel contacts a respective sidewall of the p-doped strap semiconductor layer.
    Type: Application
    Filed: August 4, 2017
    Publication date: February 7, 2019
    Inventors: Kiyohiko SAKAKIBARA, Satoshi SHIMIZU, Naoto NORIZUKI
  • Patent number: 10199359
    Abstract: A three-dimensional memory device includes a p-doped source semiconductor layer located over a substrate, a p-doped strap semiconductor layer located over the p-doped source semiconductor layer, an alternating stack of electrically conductive layers and insulating layers located over the p-doped strap semiconductor layer, and memory stack structures that extend through the alternating stack and into an upper portion of the p-doped source semiconductor layer. Each memory stack structure includes a p-doped vertical semiconductor channel and a memory film laterally surrounding the p-doped vertical semiconductor channel. A top surface of each p-doped vertical semiconductor channel contacts a bottom surface of a respective n-doped region. A sidewall of a bottom portion of each p-doped vertical semiconductor channel contacts a respective sidewall of the p-doped strap semiconductor layer.
    Type: Grant
    Filed: August 4, 2017
    Date of Patent: February 5, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Kiyohiko Sakakibara, Satoshi Shimizu, Naoto Norizuki
  • Patent number: 10192877
    Abstract: A mesa structure is formed over a substrate. An alternating stack of insulating layers and spacer material layers having a total height of approximately double the height of the mesa structure is formed over the substrate and the mesa structure. The spacer material layers are formed as, or are replaced with, electrically conductive layers. Portions of the alternating stack are removed from above the mesa structure by a planarization process. Stepped surfaces can be concurrently formed in a first terrace region overlying the mesa structure and in a second terrace region located at an opposite side of a memory array region of the alternating stack. A pair of level shifted stepped surfaces is formed. Contacts to the alternating stack can reach down only to the lowest surface of the pair of level shifted stepped surfaces, and can be shorter than the alternating stack.
    Type: Grant
    Filed: March 7, 2017
    Date of Patent: January 29, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Naoto Norizuki, Yasuchika Okizumi, Shogo Mada, Hiroyuki Ogawa
  • Publication number: 20180366487
    Abstract: A method of forming a three-dimensional memory device includes forming at the least one lower level dielectric layer over a semiconductor substrate, forming a buried source line over the least one lower level dielectric layer and over the semiconductor substrate, such that the buried source line is electrically connected to the semiconductor substrate, forming an alternating stack of insulating layers and sacrificial material layers over the buried source line, such that the sacrificial material layers are subsequently replaced with, electrically conductive layers, forming memory openings through the alternating stack by etching through the alternating stack after the buried source line is electrically connected to the semiconductor substrate, and forming memory stack structures in the memory openings. Each memory stack structure includes a vertical semiconductor channel electrically connected to the buried source line and a memory film laterally surrounding the vertical semiconductor channel.
    Type: Application
    Filed: September 29, 2017
    Publication date: December 20, 2018
    Inventors: Yasuchika Okizumi, Michiru Hirayama, Naoto Norizuki, Satoshi Shimizu, Yasuo Kasagi, Kimiaki Naruse
  • Publication number: 20180261611
    Abstract: A mesa structure is formed over a substrate. An alternating stack of insulating layers and spacer material layers having a total height of approximately double the height of the mesa structure is formed over the substrate and the mesa structure. The spacer material layers are formed as, or are replaced with, electrically conductive layers. Portions of the alternating stack are removed from above the mesa structure by a planarization process. Stepped surfaces can be concurrently formed in a first terrace region overlying the mesa structure and in a second terrace region located at an opposite side of a memory array region of the alternating stack. A pair of level shifted stepped surfaces is formed. Contacts to the alternating stack can reach down only to the lowest surface of the pair of level shifted stepped surfaces, and can be shorter than the alternating stack.
    Type: Application
    Filed: March 7, 2017
    Publication date: September 13, 2018
    Inventors: Naoto NORIZUKI, Yasuchika OKIZUMI, Shogo MADA, Hiroyuki OGAWA