Patents by Inventor Akihiro Tobioka

Akihiro Tobioka 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: 20240099014
    Abstract: At least one vertically alternating sequence of continuous insulating layers and continuous sacrificial material layers is formed over a substrate. Rows of backside support pillar structures are formed through the at least one vertically alternating sequence. Memory stack structures are formed through the at least one vertically alternating sequence. A two-dimensional array of discrete backside trenches is formed through the at least one vertically alternating sequence. Contiguous combinations of a subset of the backside trenches and a subset of the backside support pillar structures divide the at least one vertically alternating sequence into alternating stacks of insulating layers and sacrificial material layers. The sacrificial material layers are replaced with electrically conductive layers while the backside support pillar structures provide structural support to the insulating layers.
    Type: Application
    Filed: November 30, 2023
    Publication date: March 21, 2024
    Inventors: Shunsuke TAKUMA, Yuji TOTOKI, Seiji SHIMABUKURO, Tatsuya HINOUE, Kengo KAJIWARA, Akihiro TOBIOKA
  • Patent number: 11844222
    Abstract: At least one vertically alternating sequence of continuous insulating layers and continuous sacrificial material layers is formed over a substrate. Rows of backside support pillar structures are formed through the at least one vertically alternating sequence. Memory stack structures are formed through the at least one vertically alternating sequence. A two-dimensional array of discrete backside trenches is formed through the at least one vertically alternating sequence. Contiguous combinations of a subset of the backside trenches and a subset of the backside support pillar structures divide the at least one vertically alternating sequence into alternating stacks of insulating layers and sacrificial material layers. The sacrificial material layers are replaced with electrically conductive layers while the backside support pillar structures provide structural support to the insulating layers.
    Type: Grant
    Filed: January 12, 2021
    Date of Patent: December 12, 2023
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Shunsuke Takuma, Yuji Totoki, Seiji Shimabukuro, Tatsuya Hinoue, Kengo Kajiwara, Akihiro Tobioka
  • Publication number: 20230389308
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, memory openings vertically extending through the alternating stack, and memory opening fill structures located within a respective one of the memory openings. Composite drain-select-level isolation structures divide each drain-select-level electrically conductive layer into a respective plurality of electrically conductive strips. Each drain-select-level isolation structure includes a respective first drain-select-level isolation material portion vertically extending through each drain-select-level electrically conductive layers and a respective set of second drain-select-level isolation material portions vertically extending through each of the drain-select-level electrically conductive layers and at least a topmost dummy electrically conductive layer that underlies the drain-select-level electrically conductive layers.
    Type: Application
    Filed: May 26, 2022
    Publication date: November 30, 2023
    Inventor: Akihiro TOBIOKA
  • Patent number: 11749600
    Abstract: A vertically alternating sequence of unit layer stacks is formed over a substrate. Each unit layer stacks includes an insulating layer and a spacer material layer that is formed as, or is subsequently replaced with, a first electrically conductive layer. A 2×N array of stepped surfaces is formed. Each column of two stepped surfaces other than one column is vertically extended by performing a set of processing sequences at least once. The set of processing sequences includes forming a patterned etch mask layer and etching an unmasked subset of the 2×N array. One or more patterned etch mask layer has a respective continuous opening including an entire area of a respective 2×M array of stepped surfaces that is a subset of the 2×N array of stepped surfaces. Vertical stacks of memory elements are formed through the vertically alternating sequence.
    Type: Grant
    Filed: April 7, 2021
    Date of Patent: September 5, 2023
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventor: Akihiro Tobioka
  • Publication number: 20230126600
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a substrate. The spacer material layers are formed as, or are subsequently replaced with, electrically conductive layers. Memory openings and support openings are formed through the alternating stack. The memory openings are arranged in a first hexagonal array having a nearest-neighbor direction that is parallel to a first horizontal direction, and the support openings are arranged in a second hexagonal array having a nearest-neighbor direction that is perpendicular to the first horizontal direction. Memory opening fill structures are formed within a respective one of the memory openings, and support pillar structures within a respective one of the support openings.
    Type: Application
    Filed: October 26, 2021
    Publication date: April 27, 2023
    Inventors: Akihiro TOBIOKA, Yusuke TANAKA
  • 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
  • Patent number: 11495612
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings and support openings are formed through the alternating stack, and memory opening fill structures and support pillar structures are formed in the memory openings and in the support openings, respectively. Via cavities extending to each of the sacrificial material layers are formed through the alternating stack without forming any stepped surfaces in the alternating stack. The via cavities may be formed in areas that do not overlap with the support pillar structures, or in areas that include at least one support pillar structure. Sacrificial via fill structures are formed in the via cavies, and the sacrificial material layers are replaced with electrically conductive layers. The sacrificial via fill structures are removed, and a combination of a tubular dielectric spacer and a contact via structure can be formed in the via cavities.
    Type: Grant
    Filed: July 1, 2020
    Date of Patent: November 8, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yoshinobu Tanaka, Koichi Ito, Hideaki Hasegawa, Akihiro Tobioka, Sung Tae Lee
  • Publication number: 20220344266
    Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, where the electrically conductive layers include word-line-level electrically conductive layers and drain-select-level electrically conductive layers located above the word-line-level electrically conductive layers, memory opening fill structures vertically extending through the alternating stack, and drain-select-level contact via structures. A first one of the drain-select level contact structures directly contacts at least a first two of the drain-select-level electrically conductive layers that are vertically spaced apart from each other. A second one of the drain-select level contact structures directly contacts at least a second two of the drain-select-level electrically conductive layers that are vertically spaced apart from each other and which are located below the at least the first two of the drain-select-level electrically conductive layers.
    Type: Application
    Filed: February 28, 2022
    Publication date: October 27, 2022
    Inventors: Akihiro TOBIOKA, Satoshi SHIMIZU
  • Publication number: 20220328403
    Abstract: A vertically alternating sequence of unit layer stacks is formed over a substrate. Each unit layer stacks includes an insulating layer and a spacer material layer that is formed as, or is subsequently replaced with, a first electrically conductive layer. A 2×N array of stepped surfaces is formed. Each column of two stepped surfaces other than one column is vertically extended by performing a set of processing sequences at least once. The set of processing sequences includes forming a patterned etch mask layer and etching an unmasked subset of the 2×N array. One or more patterned etch mask layer has a respective continuous opening including an entire area of a respective 2×M array of stepped surfaces that is a subset of the 2×N array of stepped surfaces. Vertical stacks of memory elements are formed through the vertically alternating sequence.
    Type: Application
    Filed: April 7, 2021
    Publication date: October 13, 2022
    Inventor: Akihiro TOBIOKA
  • Patent number: 11450679
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings and support openings are formed through the alternating stack, and memory opening fill structures and support pillar structures are formed in the memory openings and in the support openings, respectively. Via cavities extending to each of the sacrificial material layers are formed through the alternating stack without forming any stepped surfaces in the alternating stack. The via cavities may be formed in areas that do not overlap with the support pillar structures, or in areas that include at least one support pillar structure. Sacrificial via fill structures are formed in the via cavies, and the sacrificial material layers are replaced with electrically conductive layers. The sacrificial via fill structures are removed, and a combination of a tubular dielectric spacer and a contact via structure can be formed in the via cavities.
    Type: Grant
    Filed: July 1, 2020
    Date of Patent: September 20, 2022
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventors: Yoshinobu Tanaka, Koichi Ito, Hideaki Hasegawa, Akihiro Tobioka, Sung Tae Lee
  • 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: 20220246636
    Abstract: A method includes forming a first-tier alternating stack of first insulating layers and first sacrificial material layers, forming a joint dielectric layer over the first-tier alternating stack, such that the joint dielectric layer is thicker than each of the first insulating layers and the first sacrificial material layers, forming a second-tier alternating stack of second insulating layers and second sacrificial material layers over the joint dielectric layer and the first-tier alternating stack, performing a level-shift anisotropic etch process to form a recess trench or via cavities vertically extending through the second-tier alternating stack and down to the joint dielectric layer, and performing an extension etching process to extend the recess trench or the via cavities through at least the joint dielectric level. At least one of etching time or etching power used during the extension etching process is different from that used during the level-shift anisotropic etch process.
    Type: Application
    Filed: February 3, 2021
    Publication date: August 4, 2022
    Inventors: Akihiro TOBIOKA, Akira YOSHIDA
  • Publication number: 20220223614
    Abstract: At least one vertically alternating sequence of continuous insulating layers and continuous sacrificial material layers is formed over a substrate. Rows of backside support pillar structures are formed through the at least one vertically alternating sequence. Memory stack structures are formed through the at least one vertically alternating sequence. A two-dimensional array of discrete backside trenches is formed through the at least one vertically alternating sequence. Contiguous combinations of a subset of the backside trenches and a subset of the backside support pillar structures divide the at least one vertically alternating sequence into alternating stacks of insulating layers and sacrificial material layers. The sacrificial material layers are replaced with electrically conductive layers while the backside support pillar structures provide structural support to the insulating layers.
    Type: Application
    Filed: January 12, 2021
    Publication date: July 14, 2022
    Inventors: Shunsuke TAKUMA, Yuji TOTOKI, Seiji SHIMABUKURO, Tatsuya HINOUE, Kengo KAJIWARA, Akihiro TOBIOKA
  • Publication number: 20220005818
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings and support openings are formed through the alternating stack, and memory opening fill structures and support pillar structures are formed in the memory openings and in the support openings, respectively. Via cavities extending to each of the sacrificial material layers are formed through the alternating stack without forming any stepped surfaces in the alternating stack. The via cavities may be formed in areas that do not overlap with the support pillar structures, or in areas that include at least one support pillar structure. Sacrificial via fill structures are formed in the via cavies, and the sacrificial material layers are replaced with electrically conductive layers. The sacrificial via fill structures are removed, and a combination of a tubular dielectric spacer and a contact via structure can be formed in the via cavities.
    Type: Application
    Filed: July 1, 2020
    Publication date: January 6, 2022
    Inventors: Yoshinobu TANAKA, Koichi ITO, Hideaki HASEGAWA, Akihiro TOBIOKA, Sung Tae LEE
  • Publication number: 20220005824
    Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings and support openings are formed through the alternating stack, and memory opening fill structures and support pillar structures are formed in the memory openings and in the support openings, respectively. Via cavities extending to each of the sacrificial material layers are formed through the alternating stack without forming any stepped surfaces in the alternating stack. The via cavities may be formed in areas that do not overlap with the support pillar structures, or in areas that include at least one support pillar structure. Sacrificial via fill structures are formed in the via cavies, and the sacrificial material layers are replaced with electrically conductive layers. The sacrificial via fill structures are removed, and a combination of a tubular dielectric spacer and a contact via structure can be formed in the via cavities.
    Type: Application
    Filed: July 1, 2020
    Publication date: January 6, 2022
    Inventors: Yoshinobu TANAKA, Koichi ITO, Hideaki HASEGAWA, Akihiro TOBIOKA, Sung Tae LEE
  • Patent number: 11189637
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a substrate. Memory stack structures are formed through the alternating stack. A pair of backside trenches and a set of nested trenches are simultaneously formed through the alternating stack. Each trench within the set of nested trenches is spaced from any other trench within the set of nested trenches by at least one patterned remaining portion of the alternating stack having a respective shape of an enclosing wall. The at least one patterned remaining portion of the alternating stack is removed from inside to outside using sequential etch processes. A dielectric pillar structure is formed within the pillar-shaped cavity. The sacrificial material layers are replaced with electrically conductive layers. A through-memory-level conductive via structure is formed through the dielectric pillar structure.
    Type: Grant
    Filed: May 29, 2020
    Date of Patent: November 30, 2021
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventor: Akihiro Tobioka
  • Patent number: 10861871
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a substrate. Memory stack structures are formed through the alternating stack. A pair of backside trenches and a set of nested trenches are simultaneously formed through the alternating stack. Each trench within the set of nested trenches is spaced from any other trench within the set of nested trenches by at least one patterned remaining portion of the alternating stack having a respective shape of an enclosing wall. The at least one patterned remaining portion of the alternating stack is removed from inside to outside using sequential etch processes. A dielectric pillar structure is formed within the pillar-shaped cavity. The sacrificial material layers are replaced with electrically conductive layers. A through-memory-level conductive via structure is formed through the dielectric pillar structure.
    Type: Grant
    Filed: March 14, 2019
    Date of Patent: December 8, 2020
    Assignee: SANDISK TECHNOLOGIES LLC
    Inventor: Akihiro Tobioka
  • Publication number: 20200295032
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a substrate. Memory stack structures are formed through the alternating stack. A pair of backside trenches and a set of nested trenches are simultaneously formed through the alternating stack. Each trench within the set of nested trenches is spaced from any other trench within the set of nested trenches by at least one patterned remaining portion of the alternating stack having a respective shape of an enclosing wall. The at least one patterned remaining portion of the alternating stack is removed from inside to outside using sequential etch processes. A dielectric pillar structure is formed within the pillar-shaped cavity. The sacrificial material layers are replaced with electrically conductive layers. A through-memory-level conductive via structure is formed through the dielectric pillar structure.
    Type: Application
    Filed: March 14, 2019
    Publication date: September 17, 2020
    Inventor: Akihiro Tobioka
  • Publication number: 20200295040
    Abstract: An alternating stack of insulating layers and spacer material layers is formed over a substrate. Memory stack structures are formed through the alternating stack. A pair of backside trenches and a set of nested trenches are simultaneously formed through the alternating stack. Each trench within the set of nested trenches is spaced from any other trench within the set of nested trenches by at least one patterned remaining portion of the alternating stack having a respective shape of an enclosing wall. The at least one patterned remaining portion of the alternating stack is removed from inside to outside using sequential etch processes. A dielectric pillar structure is formed within the pillar-shaped cavity. The sacrificial material layers are replaced with electrically conductive layers. A through-memory-level conductive via structure is formed through the dielectric pillar structure.
    Type: Application
    Filed: May 29, 2020
    Publication date: September 17, 2020
    Inventor: Akihiro Tobioka
  • Patent number: 10274841
    Abstract: A reticle for a semiconductor lithography process includes a glass plate having regions with a reduced optical transmission factor. The regions may include arrays of elements comprising defects such as cracks or voids which are formed by laser pulses. The regions may be adjacent to openings in an opaque material at the bottom of the reticle to shield the openings from a portion of the light which illuminates the reticle from the top. As a result, the light which exits the reticle and is used to pattern a substrate has an asymmetric intensity. This allows the substrate to be patterned with an inspection mark which indicates whether a defocus condition exists, and whether there is a positive or negative defocus condition. Related methods use a reticle to form a pattern on a substrate and for adjusting a focus condition using a reticle.
    Type: Grant
    Filed: October 4, 2017
    Date of Patent: April 30, 2019
    Assignee: SanDisck Technologies LLC
    Inventor: Akihiro Tobioka