Patents by Inventor Michiaki Sano

Michiaki Sano 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: 11973026
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory openings located in a memory array region and vertically extending through the alternating stack, memory opening fill structures located in the memory openings, and laterally-isolated contact via assemblies located in a contact region. Each of the laterally-isolated contact via assemblies includes a contact via structure contacting a top surface of a respective one of the electrically conductive layers and an insulating spacer laterally surrounding the contact via structure and having an outer surface having a corrugated vertical cross-sectional profile in which first portions of the insulating spacer located at levels of the electrically conductive layers laterally protrude outward relative to second portions of the insulating spacer located at levels of the insulating layers.
    Type: Grant
    Filed: March 2, 2022
    Date of Patent: April 30, 2024
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Michiaki Sano, Koichi Ito
  • Publication number: 20240096695
    Abstract: A conductive hard mask layer can be patterned with peripheral discrete openings. An anisotropic etch process can be performed to form peripheral discrete via cavities, which are subsequently expanded to form a continuous moat trench. An edge seal structure can be formed in the continuous moat trench. Alternatively, a conductive bridge structure may be formed prior to formation of a patterned conductive hard mask layer, and a moat trench can be formed around a periphery of the semiconductor die while the conductive bridge structure provides electrical connection between an inner portion and an outer portion of the conductive hard mask layer. The entire conductive hard mask layer can be electrically connected to a semiconductor substrate to reduce or prevent arcing during an anisotropic etch process that forms the peripheral discrete via cavities or the moat trench.
    Type: Application
    Filed: September 16, 2022
    Publication date: March 21, 2024
    Inventors: Michiaki SANO, Tatsuya HINOUE
  • Publication number: 20230417687
    Abstract: Systems and methods for non-destructive inspection of semiconductor devices, such as three-dimensional NAND memory device, using reflective X-ray microscope computed tomographic (CT) imaging. An X-ray microscope directs a focused beam of X-ray radiation at an oblique angle onto the surface of a semiconductor wafer such that the beam passes through device structures and at least a portion of the beam is reflected by a semiconductor substrate of the wafer and detected by an X-ray detector. The wafer may be rotated about a rotation axis to obtain X-ray images of a region-of-interest (ROI) at different projection angles. A processing unit uses detected X-ray image data obtained by the X-ray detector at the different projection angles to generate a CT reconstructed image of the ROI.
    Type: Application
    Filed: June 24, 2022
    Publication date: December 28, 2023
    Inventors: Shogo TOMITA, Tatsuya HINOUE, Michiaki SANO
  • Publication number: 20230380151
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, where the electrically conductive layers include word lines and drain select gate electrodes that contain plurality of drain-select-level electrically conductive strips which are located above the word lines, memory stack structures vertically extending through the alternating stack, drain-select-level isolation structures located between a respective neighboring pair of drain-select-level electrically conductive strips, and a first laterally-insulated contact via assembly including a first layer contact via structure and a first tubular insulating spacer. The first laterally-insulated contact via assembly contacts a top surface of a first word line of the word lines, and the first laterally-insulated contact via assembly laterally contacts a first drain-select-level isolation structure of the drain-select-level isolation structures.
    Type: Application
    Filed: May 18, 2022
    Publication date: November 23, 2023
    Inventors: Michiaki SANO, Koichi ITO, Takyua MORI
  • Patent number: 11778818
    Abstract: An alternating stack of insulating layers and electrically conductive layers, a retro-stepped dielectric material portion overlying stepped surfaces of the alternating stack, and memory stack structures extending through the alternating stack are formed over a substrate. A patterned etch mask layer including discrete openings is formed thereabove. Via cavities through an upper region of the retro-stepped dielectric material portion by performing a first anisotropic etch process. Metal plates are selectively formed on physically exposed surfaces of a first subset of the electrically conductive layers by a selective metal deposition process. A subset of the via cavities without any metal plates therein are vertically extended downward by performing a second anisotropic etch process while the metal plates protect underlying electrically conductive layers. Via cavities can be formed without punching through electrically conductive layers.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: October 3, 2023
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Ryo Mochizuki, Yasuo Kasagi, Michiaki Sano, Junji Oh, Yujin Terasawa, Hiroaki Namba
  • Patent number: 11569139
    Abstract: A method includes providing a first wafer including a respective set of first metal bonding pads and at least one first alignment diagnostic structure, providing a second wafer including a respective set of second metal bonding pads and a respective set of second alignment diagnostic structures, overlaying the first wafer and the second wafer, measuring at least one of a current, voltage or contact resistance between the first alignment diagnostic structures and the second alignment diagnostic structures to determine an overlay offset, and bonding the second wafer to the first wafer.
    Type: Grant
    Filed: March 8, 2021
    Date of Patent: January 31, 2023
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Ikue Yokomizo, Michiaki Sano, Kazuto Watanabe, Hajime Yamamoto, Takashi Yamaha, Koichi Ito, Katsuya Kato, Ryo Hiramatsu, Hiroshi Sasaki, Akihiro Tobioka, Liang Li
  • Publication number: 20220352200
    Abstract: A method of forming a three-dimensional memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate, forming a memory opening extending through the alternating stack, forming a sacrificial memory opening fill structure in the memory opening, replacing the sacrificial material layers with electrically conductive layers, removing the sacrificial memory opening fill structure selective to the electrically conductive layers, and forming a memory opening fill structure the memory opening after replacing the sacrificial material layers with electrically conductive layers and after removing the sacrificial memory opening fill structure. The memory opening fill structure includes a memory film and a vertical semiconductor channel.
    Type: Application
    Filed: November 10, 2021
    Publication date: November 3, 2022
    Inventors: Michiaki SANO, Yusuke MUKAE, Naoki TAKEGUCHI, Yujin TERASAWA, Tatsuya HINOUE, Ramy Nashed Bassely SAID
  • Publication number: 20220328413
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, memory openings located in a memory array region and vertically extending through the alternating stack, memory opening fill structures located in the memory openings, and laterally-isolated contact via assemblies located in a contact region that is located adjacent to the memory array region. Each of the laterally-isolated contact via assemblies includes a contact via structure contacting a top surface of a respective one of the electrically conductive layers and a dielectric spacer laterally surrounding the contact via structure. Each contact via structure other than a contact via structure contacting a topmost one of the electrically conductive layers extends through and is laterally surrounded by each electrically conductive layer that overlies the respective electrically conductive layer.
    Type: Application
    Filed: June 20, 2022
    Publication date: October 13, 2022
    Inventors: Tomohiro KUBO, Michiaki SANO
  • Publication number: 20220285234
    Abstract: A method includes providing a first wafer including a respective set of first metal bonding pads and at least one first alignment diagnostic structure, providing a second wafer including a respective set of second metal bonding pads and a respective set of second alignment diagnostic structures, overlaying the first wafer and the second wafer, measuring at least one of a current, voltage or contact resistance between the first alignment diagnostic structures and the second alignment diagnostic structures to determine an overlay offset, and bonding the second wafer to the first wafer.
    Type: Application
    Filed: March 8, 2021
    Publication date: September 8, 2022
    Inventors: Ikue YOKOMIZO, Michiaki SANO, Kazuto WATANABE, Hajime YAMAMOTO, Takashi YAMAHA, Koichi ITO, Katsuya KATO, Ryo HIRAMATSU, Hiroshi SASAKI, Akihiro TOBIOKA, Liang LI
  • Publication number: 20220189872
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory openings located in a memory array region and vertically extending through the alternating stack, memory opening fill structures located in the memory openings, and laterally-isolated contact via assemblies located in a contact region. Each of the laterally-isolated contact via assemblies includes a contact via structure contacting a top surface of a respective one of the electrically conductive layers and an insulating spacer laterally surrounding the contact via structure and having an outer surface having a corrugated vertical cross-sectional profile in which first portions of the insulating spacer located at levels of the electrically conductive layers laterally protrude outward relative to second portions of the insulating spacer located at levels of the insulating layers.
    Type: Application
    Filed: March 2, 2022
    Publication date: June 16, 2022
    Inventors: Michiaki SANO, Koichi ITO
  • Publication number: 20220028879
    Abstract: An alternating stack of insulating layers and electrically conductive layers, a retro-stepped dielectric material portion overlying stepped surfaces of the alternating stack, and memory stack structures extending through the alternating stack are formed over a substrate. A patterned etch mask layer including discrete openings is formed thereabove. Via cavities through an upper region of the retro-stepped dielectric material portion by performing a first anisotropic etch process. Metal plates are selectively formed on physically exposed surfaces of a first subset of the electrically conductive layers by a selective metal deposition process. A subset of the via cavities without any metal plates therein are vertically extended downward by performing a second anisotropic etch process while the metal plates protect underlying electrically conductive layers. Via cavities can be formed without punching through electrically conductive layers.
    Type: Application
    Filed: July 21, 2020
    Publication date: January 27, 2022
    Inventors: Ryo MOCHIZUKI, Yasuo KASAGI, Michiaki SANO, Junji OH, Yujin TERASAWA, Hiroaki NAMBA
  • Patent number: 11101289
    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: August 24, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yu Ueda, Michiaki Sano
  • Publication number: 20210257378
    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: Yu UEDA, Michiaki SANO
  • Patent number: 10994239
    Abstract: A gas scrubber includes a canister having a rotatable spiral separator which provides a non-linear path configured to be filled with modular adsorbent material portions between a gas inlet and a gas outlet.
    Type: Grant
    Filed: March 8, 2018
    Date of Patent: May 4, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Michiaki Sano, Jo Sato
  • Patent number: 10923496
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a source-level sacrificial layer overlying a substrate. The spacer material layers are formed as, or are subsequently replaced with, electrically conductive layers. Memory stack structures including a respective vertical semiconductor channel and a respective memory film are formed through the alternating stack. A source-level cavity is formed by removing the source-level sacrificial layer. Semiconductor pillar structures may be used to provide mechanical support to the alternating stack during formation of the source-level cavity. A source-level semiconductor material layer can be formed in the source-level cavity. The source-level semiconductor material layer adjoins bottom end portions of the vertical semiconductor channels and laterally surrounds the semiconductor pillar structures.
    Type: Grant
    Filed: January 7, 2019
    Date of Patent: February 16, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Mitsuteru Mushiga, Kenji Sugiura, Akio Nishida, Ryosuke Kaneko, Michiaki Sano
  • Publication number: 20200321324
    Abstract: A bonded assembly includes a first stack containing a first semiconductor die bonded to a second semiconductor die along a stacking direction, first external bonding pads formed within the first semiconductor die, and bonding connection wires. Each of the bonding connection wires extends over a sidewall of the first semiconductor die and protrudes into the first semiconductor die through the sidewall of the first semiconductor die to contact a respective one of the first external bonding pads.
    Type: Application
    Filed: April 2, 2019
    Publication date: October 8, 2020
    Inventors: Michiaki Sano, Takashi YAMAHA, Koichi ITO, Ikue YOKOMIZO, Ryo HIRAMATSU, Kazuto WATANABE, Katsuya KATO, Hajime YAMAMOTO, Hiroshi SASAKI
  • Patent number: 10797035
    Abstract: A bonded assembly includes a first stack containing a first semiconductor die bonded to a second semiconductor die along a stacking direction, first external bonding pads formed within the first semiconductor die, and bonding connection wires. Each of the bonding connection wires extends over a sidewall of the first semiconductor die and protrudes into the first semiconductor die through the sidewall of the first semiconductor die to contact a respective one of the first external bonding pads.
    Type: Grant
    Filed: April 2, 2019
    Date of Patent: October 6, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Michiaki Sano, Takashi Yamaha, Koichi Ito, Ikue Yokomizo, Ryo Hiramatsu, Kazuto Watanabe, Katsuya Kato, Hajime Yamamoto, Hiroshi Sasaki
  • Patent number: 10790296
    Abstract: A bonded structure may be formed by measuring die areas of first semiconductor dies on a wafer at a measurement temperature, generating a two-dimensional map of local target temperatures that are estimated to thermally adjust a die area of each of the first semiconductor dies to a target die area, loading the wafer to a bonding apparatus comprising at least one temperature sensor, and iteratively bonding a plurality of second semiconductor dies to a respective one of the first semiconductor dies by sequentially adjusting a temperature of the wafer to a local target temperature of a respective first semiconductor die that is bonded to a respective one of the second semiconductor dies. An apparatus for forming such a bonded structure may include a computer, a chuck for holding the wafer, a die attachment unit, and a temperature control mechanism.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: September 29, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Takashi Yamaha, Katsuya Kato, Kazuto Watanabe, Hajime Yamamoto, Michiaki Sano, Koichi Ito, Ikue Yokomizo, Ryo Hiramatsu, Hiroshi Sasaki
  • 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: 20200219895
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a source-level sacrificial layer overlying a substrate. The spacer material layers are formed as, or are subsequently replaced with, electrically conductive layers. Memory stack structures including a respective vertical semiconductor channel and a respective memory film are formed through the alternating stack. A source-level cavity is formed by removing the source-level sacrificial layer. Semiconductor pillar structures may be used to provide mechanical support to the alternating stack during formation of the source-level cavity. A source-level semiconductor material layer can be formed in the source-level cavity. The source-level semiconductor material layer adjoins bottom end portions of the vertical semiconductor channels and laterally surrounds the semiconductor pillar structures.
    Type: Application
    Filed: January 7, 2019
    Publication date: July 9, 2020
    Inventors: Mitsuteru MUSHIGA, Kenji SUGIURA, Akio NISHIDA, Ryosuke KANEKO, Michiaki SANO