Patents by Inventor Keisuke SHIGEMURA

Keisuke SHIGEMURA 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: 20250113485
    Abstract: A three-dimensional memory device includes a pair of alternating stacks of insulating layers and electrically conductive layers that are laterally spaced from each other by a lateral isolation trench that laterally extend along a first horizontal direction, memory openings vertically extending through a respective one of the pair of alternating stacks, memory opening fill structures located in a respective one of the memory openings, and a lateral isolation trench fill structure located in the lateral isolation trench and including a plurality of neck portions having a first width, and a plurality of laterally bulging portions having a second width along the second horizontal direction that is greater than the first width, and interlaced with the plurality of neck portions along the first horizontal direction.
    Type: Application
    Filed: September 29, 2023
    Publication date: April 3, 2025
    Inventors: Wataru MURANAGA, Yoshihiro NAGURA, Atsushi SHIMIZU, Keisuke SHIGEMURA
  • Publication number: 20250113492
    Abstract: A three-dimensional memory device includes a pair of alternating stacks of insulating layers and electrically conductive layers that are laterally spaced from each other by a lateral isolation trench that laterally extends along a first horizontal direction, memory opening fill structures including a respective vertical stack of memory elements and a vertical semiconductor channel, support pillar structures extending in rows along the first horizontal direction with a uniform pitch, and a lateral isolation trench fill structure located in the lateral isolation trench and having a variable width along a second horizontal direction, the variable width having a periodic undulation along the first horizontal direction with a periodicity that is the same as the uniform pitch.
    Type: Application
    Filed: November 14, 2023
    Publication date: April 3, 2025
    Inventors: Wataru MURANAGA, Keisuke SHIGEMURA, Atsushi SHIMIZU
  • Publication number: 20240107758
    Abstract: A method of forming a three-dimensional semiconductor device includes forming an alternating stack of insulating layers and spacer material layers over a substrate, forming memory openings formed in the memory array region and monitor openings formed in a monitor region though the alternating stack, forming memory opening fill structures in the memory openings, forming monitor opening fill structures by depositing a monitor opening fill material in the monitor openings, recessing first portions of the alternating stack in a contact region and second portions of the alternating stack in the monitor region, and determining at least one characteristic of the recessed surfaces of the monitor opening fill structures. At least one characteristic of the memory openings or memory opening fill structures may be determined based on the determining at least one characteristic of the recessed surfaces of the monitor opening fill structures.
    Type: Application
    Filed: September 28, 2022
    Publication date: March 28, 2024
    Inventors: Hiroyuki OGAWA, Masato MIYAMOTO, Keisuke SHIGEMURA
  • Patent number: 11637119
    Abstract: A row of backside support pillar structures is formed through a first-tier alternating stack of first-tier insulating layers and first-tier sacrificial material layers. At least one upper-tier alternating stack can be formed, and memory stack structures can be formed through the alternating stacks. A backside trench can be formed through the alternating stacks selective to the row of backside support pillar structures. The sacrificial material layers are replaced with electrically conductive layers, and the backside trench can be filled with a backside trench fill structure, which includes the row of backside support pillar structures. The row of backside support pillar structures reduces or prevents tilting or collapse of the alternating stacks during replacement of the sacrificial material layers with the electrically conductive layers.
    Type: Grant
    Filed: December 28, 2020
    Date of Patent: April 25, 2023
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Kohei Yamaguchi, Keisuke Shigemura, Kengo Kajiwara
  • Patent number: 11410924
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers containing steps, memory stack structures extending through the alternating stack, a first contact via structure which contacts a top surface of a respective upper electrically conductive layer in a first step, a first dielectric spacer which does not contact any of the electrically conductive layers other than the respective upper electrically conductive layer in the first step, a second contact via structure which contacts a top surface of a respective lower electrically conductive layer in the first step, and a second dielectric spacer which extends through the respective upper electrically conductive layer, and which contacts the respective lower electrically conductive layer.
    Type: Grant
    Filed: August 21, 2020
    Date of Patent: August 9, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Haruki Suwa, Keisuke Shigemura, Akihiro Shimada
  • Publication number: 20220059454
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers containing steps, memory stack structures extending through the alternating stack, a first contact via structure which contacts a top surface of a respective upper electrically conductive layer in a first step, a first dielectric spacer which does not contact any of the electrically conductive layers other than the respective upper electrically conductive layer in the first step, a second contact via structure which contacts a top surface of a respective lower electrically conductive layer in the first step, and a second dielectric spacer which extends through the respective upper electrically conductive layer, and which contacts the respective lower electrically conductive layer.
    Type: Application
    Filed: August 21, 2020
    Publication date: February 24, 2022
    Inventors: Haruki SUWA, Keisuke SHIGEMURA, Akihiro SHIMADA
  • Publication number: 20210358937
    Abstract: A row of backside support pillar structures is formed through a first-tier alternating stack of first-tier insulating layers and first-tier sacrificial material layers. At least one upper-tier alternating stack can be formed, and memory stack structures can be formed through the alternating stacks. A backside trench can be formed through the alternating stacks selective to the row of backside support pillar structures. The sacrificial material layers are replaced with electrically conductive layers, and the backside trench can be filled with a backside trench fill structure, which includes the row of backside support pillar structures. The row of backside support pillar structures reduces or prevents tilting or collapse of the alternating stacks during replacement of the sacrificial material layers with the electrically conductive layers.
    Type: Application
    Filed: December 28, 2020
    Publication date: November 18, 2021
    Inventors: Kohei YAMAGUCHI, Keisuke SHIGEMURA, Kengo KAJIWARA
  • Patent number: 10347647
    Abstract: A memory device contains a stack of insulating layers and electrically conductive word line layers, at least one first drain select gate electrode located over the stack and extending through a first drain select transistor and a second drain select transistor, at least one second drain select gate electrode located between the first drain select electrode and the stack, and extending through a third drain select transistor and a fourth drain select transistor. The first drain select transistor and the third drain select transistor are located in a first NAND memory string. The second drain select transistor and the fourth drain select transistor are located in a second NAND memory string different from the first NAND memory string. The first drain select transistor has a higher threshold voltage than the second drain select transistor. The third drain select transistor has a lower threshold voltage than the fourth drain select transistor.
    Type: Grant
    Filed: December 21, 2017
    Date of Patent: July 9, 2019
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Naohiro Hosoda, Keisuke Shigemura, Junichi Ariyoshi, Kazuki Kajitani, Yuji Fukano
  • Publication number: 20190198515
    Abstract: A memory device contains a stack of insulating layers and electrically conductive word line layers, at least one first drain select gate electrode located over the stack and extending through a first drain select transistor and a second drain select transistor, at least one second drain select gate electrode located between the first drain select electrode and the stack, and extending through a third drain select transistor and a fourth drain select transistor. The first drain select transistor and the third drain select transistor are located in a first NAND memory string. The second drain select transistor and the fourth drain select transistor are located in a second NAND memory string different from the first NAND memory string. The first drain select transistor has a higher threshold voltage than the second drain select transistor. The third drain select transistor has a lower threshold voltage than the fourth drain select transistor.
    Type: Application
    Filed: December 21, 2017
    Publication date: June 27, 2019
    Inventors: Naohiro HOSODA, Keisuke SHIGEMURA, Junichi ARIYOSHI, Kazuki KAJITANI, Yuji FUKANO
  • Patent number: 10083982
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, the alternating stack having a memory array region and a contact region containing stepped surfaces, and memory stack structures having a semiconductor channel and a memory film extending through the memory array region of the alternating stack. The electrically conductive layers include a drain select gate electrode and word lines, where the drain select gate electrode is thicker than each of the word lines.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: September 25, 2018
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Keisuke Shigemura, Junichi Ariyoshi, Masanori Tsutsumi, Michiaki Sano, Yanli Zhang, Raghuveer S. Makala
  • Publication number: 20180138194
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, the alternating stack having a memory array region and a contact region containing stepped surfaces, and memory stack structures having a semiconductor channel and a memory film extending through the memory array region of the alternating stack. The electrically conductive layers include a drain select gate electrode and word lines, where the drain select gate electrode is thicker than each of the word lines.
    Type: Application
    Filed: April 25, 2017
    Publication date: May 17, 2018
    Inventors: Keisuke SHIGEMURA, Junichi ARIYOSHI, Masanori TSUTSUMI, Michiaki SANO, Yanli ZHANG, Raghuveer S. MAKALA