Patents by Inventor Nozomu Harada

Nozomu Harada 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: 20220415901
    Abstract: Provided is a step of forming, on a P-layer substrate 20, an N+ layer 21A to be connected to a source line SL, Si pillars 25a to 25d, N+ layers 23A to 23D to be connected to bit lines BL1 and BL2, HfO2 layers 30a and 32 surrounding lower and upper portions of the Si pillars 25a to 25d, a TiN layer 31a to be connected to a plate line PL, and TiN layers 33a and 33b to be connected to word lines WL1 and WL2. P layers 27a to 27d are formed so as to surround the Si pillars 25a to 25d and so as to be deposited on them to form a plurality of dynamic flash memory cells arranged in rows and columns.
    Type: Application
    Filed: June 22, 2022
    Publication date: December 29, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220415662
    Abstract: A first mask material layer on a Si pillar 7a and a first material layer around a side surface of a top portion of the Si pillar 7a are formed. A second material layer is then formed on an outer periphery of the first material layer. The first mask material layer and the first material layer are then etched by using the second material layer as a mask. A thin SiGe layer, a p+ layer 23a, and a SiO2 layer 24a are then formed in a recessed portion formed around the Si pillar 7a. The exposed side surface of the thin SiGe layer is oxidized to form a SiO2 layer 26a. A TiN layer and a W layer, which are gate conductor layers, are etched by using the SiO2 layers 24a and 26a as masks to form a TiN layer 29a and a W layer 30a.
    Type: Application
    Filed: September 2, 2022
    Publication date: December 29, 2022
    Inventor: Nozomu HARADA
  • Publication number: 20220406781
    Abstract: A memory device includes a page made up of plural memory cells arranged in a column on a substrate, and a page write operation is performed to hold positive hole groups generated by an impact ionization phenomenon, in a channel semiconductor layer by controlling voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity region, and a second impurity region of each memory cell contained in the page and a page erase operation is performed to remove the positive hole groups out of the channel semiconductor layer by controlling voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity region, and the second impurity region. The first impurity layer of the memory cell is connected with a source line, the second impurity layer is connected with a bit line, one of the first gate conductor layer and the second gate conductor layer is connected with a word line, and another is connected with a drive control line.
    Type: Application
    Filed: June 21, 2022
    Publication date: December 22, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220406780
    Abstract: A memory device includes a page made up of plural memory cells arranged in a column on a substrate, and a page write operation is performed to hold positive hole groups generated by an impact ionization phenomenon, in a channel semiconductor layer by controlling voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity region, and a second impurity region of each memory cell contained in the page and a page erase operation is performed to remove the positive hole groups out of the channel semiconductor layer by controlling voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity region, and the second impurity region.
    Type: Application
    Filed: June 21, 2022
    Publication date: December 22, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220392900
    Abstract: There are an N+ layer connected to a source line SL and an N+ layer connected to a bit line BL at both ends of a Si pillar standing on a substrate in a perpendicular direction, a P+ layer connected to the N+ layer, a first gate insulating layer surrounding the Si pillar, a first gate conductor layer surrounding the first gate insulating layer and connected to a plate line PL, and a second gate conductor layer surrounding a gate HfO2 layer surrounding the Si pillar and connected to a word line WL. The voltages applied to the source line SL, the plate line PL, the word line WL, and the bit line BL are controlled to perform a data hold operation of holding a group of holes generated by an impact ionization phenomenon or a gate-induced drain leakage current inside a channel region of the Si pillar and a data erase operation of removing the group of holes from the channel region.
    Type: Application
    Filed: August 10, 2022
    Publication date: December 8, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220384446
    Abstract: A first impurity layer 101a and a second impurity layer 101b are formed on a substrate Sub at both ends of a Si pillar 100 standing in a vertical direction and having a circular or rectangular horizontal cross-section. Then, a first gate insulating layer 103a and a second gate insulating layer 103b surrounding the Si pillar 100, a first gate conductor layer 104a surrounding the first gate insulating layer 103a, and a second gate conductor layer 104b surrounding the second gate insulating layer 103b are formed. Then, a voltage is applied to the first impurity layer 101a, the second impurity layer 101b, the first gate conductor layer 104a, and the second gate conductor layer 104b to generate an impact ionization phenomenon in a channel region 102 by current flowing between the first impurity layer 101a and the second impurity layer 101b.
    Type: Application
    Filed: June 14, 2022
    Publication date: December 1, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220375528
    Abstract: A memory device includes pages arranged in columns and each constituted by a plurality of memory cells on a substrate, voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity layer, and a second impurity layer in each memory cell included in each of the pages are controlled to perform a page write operation of retaining, inside a channel semiconductor layer, a group of positive holes generated by an impact ionization phenomenon or by a gate-induced drain leakage current, and the voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity layer, and the second impurity layer are controlled to perform a page erase operation of discharging the group of positive holes from inside the channel semiconductor layer.
    Type: Application
    Filed: May 9, 2022
    Publication date: November 24, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220367468
    Abstract: Provided on a substrate are an N+ layer connecting to a source line SL and an N+ layer connecting to a bit line BL that are located at opposite ends of a Si pillar standing in an upright position along the vertical direction, an N layer continuous with the N+ layer, an N layer continuous with the N+ layer, a first gate insulating layer surrounding the Si pillar, a first gate conductor layer surrounding the first gate insulating layer and connecting to a plate line PL, and a second gate conductor layer surrounding a second gate insulating layer surrounding the Si pillar and connecting to a word line WL. A voltage applied to each of the source line SL, the plate line PL, the word line WL, and the bit line BL is controlled to perform a data retention operation for retaining holes, which have been generated through an impact ionization phenomenon or using a gate induced drain leakage current, in a channel region of the Si pillar, and a data erase operation for removing the holes from the channel region.
    Type: Application
    Filed: May 9, 2022
    Publication date: November 17, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220367469
    Abstract: A memory device includes pages, each being composed of a plurality of memory cells arrayed on a substrate in row form. The memory device controls voltages to be applied to a first gate conductor layer, a second gate conductor layer, a first impurity region, and a second impurity region of each of the memory cells included in the pages to perform a page write operation of holding a hole group formed by an impact ionization phenomenon or a gate induced drain leakage current in a channel semiconductor layer, and controls voltages to be applied to the first gate conductor layer, the second gate conductor layer, the third gate conductor layer, the fourth gate conductor layer, the first impurity region, and the second impurity region to perform a page erase operation of removing the hole group out of the channel semiconductor layer.
    Type: Application
    Filed: May 11, 2022
    Publication date: November 17, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220367729
    Abstract: On a substrate, an N+ layer connecting to a source line SL, a first Si pillar standing in a perpendicular direction, and a second Si pillar on the first Si pillar are disposed. In a central portion of the first Si pillar, a P+ layer is disposed, and a P layer is disposed so as to surround the P+ layer. In a central portion of the second Si pillar, a P+ layer is disposed, and a P layer is disposed so as to surround the P+ layer. On the second Si pillar, an N+ layer is disposed so as to connect to a bit line BL. A first gate insulating layer is disposed so as to surround the first Si pillar, and a second gate insulating layer is disposed so as to surround the second Si pillar. A first gate conductor layer is disposed so as to surround the first insulating layer and to connect to a plate line PL, and a second gate conductor layer is disposed so as to surround the second insulating layer and to connect to a word line WL.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 17, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220367474
    Abstract: In a memory device, pages are arrayed in a column direction on a substrate, each page constituted by memory cells arrayed in row direction on a substrate. Each memory cell includes a zonal P layer. N+ layers continuous with a source line and a bit line respectively are on both sides of the P layer. Gate insulating layers surround part of the P layer continuous with the N+ layer and part of the P layer continuous with the N+ layer, respectively. One side surface of the gate insulating layer is covered with a gate conductor layer continuous with a first plate line, and the other side surface is covered with a gate conductor layer continuous with a second plate line. A gate conductor layer continuous with a word line surrounds the gate insulating layer.
    Type: Application
    Filed: July 25, 2022
    Publication date: November 17, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220367680
    Abstract: A memory device includes pages arranged in columns and each constituted by a plurality of memory cells on a substrate, voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity layer, and a second impurity layer in each memory cell included in each of the pages are controlled to perform a page write operation of retaining, inside a channel semiconductor layer, a group of positive holes generated by an impact ionization phenomenon or by a gate-induced drain leakage current, and the voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity layer, and the second impurity layer are controlled to perform a page erase operation of discharging the group of positive holes from inside the channel semiconductor layer.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 17, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220367467
    Abstract: An N+ layer 21 connected to a source line SL on a substrate 20 has thereon first Si pillars 22aa to 22da. The Si pillars 22aa to 22da are surrounded, and Lg1 between opposing intersections among intersections between a line X-X? and outer peripheral edges of HfO2 layers 24a serving as gate insulating layers surrounding the Si pillars 22aa and 22ba is larger than a thickness Lg2 of the HfO2 layers 24a crossing a line Y-Y? and is smaller than twice the thickness Lg2. Further, TiN layers 25aa and 25ba are connected to plate lines PL1a and PL1br, and TiN layers 25ab and 25bb are connected to plate lines PL2a and PL2b, the TiN layers 25aa and 25ba and the TiN layers 25ab and 25bb surrounding the HfO2 layers 24a, extending in the line X-X? direction, and being separated from each other.
    Type: Application
    Filed: May 9, 2022
    Publication date: November 17, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220367679
    Abstract: Provided on a substrate 1 are an N+ layer connecting to a source line SL, a first Si pillar as a P+ layer standing in an upright position along the vertical direction, and a second Si pillar as a P layer. An N+ layer connecting to a bit line BL is provided on the second Si pillar. A first gate insulating layer is provided so as to surround the first Si pillar, and a second gate insulating layer is provided so as to surround the second Si pillar. A first gate conductor layer connecting to a plate line PL is provided so as to surround the first insulating layer, and a second gate conductor layer connecting to a word line WL is provided so as to surround the second insulating layer.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 17, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220367471
    Abstract: A memory device includes pages arranged in columns and each constituted by a plurality of memory cells on a substrate, voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity layer, and a second impurity layer in each memory cell included in each of the pages are controlled to perform a page write operation of retaining, inside a channel semiconductor layer, a group of positive holes generated by an impact ionization phenomenon or by a gate-induced drain leakage current, and the voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity layer, and the second impurity layer are controlled to perform a page erase operation of discharging the group of positive holes from inside the channel semiconductor layer.
    Type: Application
    Filed: May 12, 2022
    Publication date: November 17, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220367473
    Abstract: In a memory device, pages are arrayed in a column direction, each page constituted by memory cells arrayed in row direction on an insulating substrate. Each memory cell includes a zonal P layer. N+ layers continuous with a source line and a bit line respectively are on both sides of the P layer. Gate insulating layers surround part of the P layer continuous with the N+ layer and part of the P layer continuous with the N+ layer 3b, respectively. One side surface and the other side surface of the gate insulating layer are covered with a gate conductor layer continuous with a first plate line and a gate conductor layer continuous with a second plate line, respectively. A gate conductor layer continuous with a word line surrounds the gate insulating layer.
    Type: Application
    Filed: July 25, 2022
    Publication date: November 17, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220367681
    Abstract: An N+ layer, a Si base material formed of a first channel region and a second channel region, and an N+ layer are disposed parallel to a substrate so as to be connected to each other. A first gate insulating layer that surrounds the first channel region and a second gate insulating layer that surrounds the second channel region are disposed. A first gate conductor layer that surrounds the first gate insulating layer and a second gate conductor layer that surrounds the second gate insulating layer are disposed. The first gate conductor layer is connected to a plate line PL, and the second gate conductor layer is connected to a word line WL. The N+ layer is connected to a source line, and the N+ layer is connected to a bit line BL. These constitute one dynamic flash memory cell. A plurality of cells are disposed in the vertical direction and in the horizontal direction relative to the substrate to form a dynamic flash memory.
    Type: Application
    Filed: May 12, 2022
    Publication date: November 17, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220367470
    Abstract: There are provided the steps of forming an N+ layer 21a and a Si pillar 26 on a substrate 20, the N+ layer 21a being connected to a source line SL, the Si pillar 26 standing in a vertical direction and being composed of a P+ layer 22a in a center portion thereof and a P layer 25a surrounding the P+ layer 22a; forming an N+ layer 3b and HfO2 layers 28a and 28b of gate insulating layers on the P+ layer 22a, the N+ layer 3b being connected to a bit line BL, the HfO2 layers 28a and 28b surrounding the Si pillar 26; and forming a TiN layer 30a of a gate conductor layer and a TiN layer 30b of a gate conductor layer, the TiN layer 30a surrounding the HfO2 layer 28a and being connected to a plate line PL, the TiN layer 30b surrounding the HfO2 layer 28b and being connected to a word line WL.
    Type: Application
    Filed: May 11, 2022
    Publication date: November 17, 2022
    Inventors: Nozomu HARADA, Koji SAKUI
  • Publication number: 20220366986
    Abstract: A memory device includes pages, each being composed of a plurality of memory cells arrayed on a substrate in row form, and controls voltages to be applied to a first gate conductor layer, a second gate conductor layer, a first impurity layer, and a second impurity layer of each of the memory cells included in the pages to perform a page write operation of holding a hole group generated by an impact ionization phenomenon or a gate induced drain leakage current in a channel semiconductor layer, and controls voltages to be applied to the first gate conductor layer, the second gate conductor layer, the third gate conductor layer, the fourth gate conductor layer, the first impurity layer, and the second impurity layer to perform a page erase operation of removing the hole group out of the channel semiconductor layer.
    Type: Application
    Filed: May 11, 2022
    Publication date: November 17, 2022
    Inventors: Koji SAKUI, Nozomu HARADA
  • Publication number: 20220359520
    Abstract: Si pillars 22a to 22d stand on an N+ layer 21 connected to a source line SL. Lower portions of the Si pillars 22a to 22d are surrounded by a HfO2 layer 25a, which is surrounded by TiN layers 26a and 26b that are respectively connected to plate lines PL1 and PL2 and are isolated from each other. Upper portions of the Si pillars 22a to 22d are surrounded by a HfO2 layer 25b, which is surrounded by TiN layers 28a and 28b that are respectively connected to word lines WL1 and WL2 and are isolated from each other. A thickness Lg1 of the TiN layer 26a on a line X-X? is smaller than twice a thickness Lg2 of the TiN layer 26a on a line Y-Y? and is larger than or equal to the thickness Lg2. The thickness Lg1 of the TiN layer 28a on the line X-X? is smaller than twice the thickness Lg2 of the TiN layer 28a on the line Y-Y?.
    Type: Application
    Filed: May 3, 2022
    Publication date: November 10, 2022
    Inventors: Nozomu HARADA, Koji SAKUI