Patents by Inventor Makoto Iwai

Makoto Iwai 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: 10032958
    Abstract: A seed crystal substrate 8 includes a base body 1 and a plurality of rows of stripe-shaped seed crystal layers 3 formed on the base body 1. An upper face 3a of the seed crystal layer 3 is (11-22) plane, a groove 4 is formed between the adjacent seed crystal layers 3, and a longitudinal direction of the groove 4 is a direction in which a c-axis of a crystal forming the seed crystal layer is projected on the upper face. A nitride of a group 13 element is formed on the seed crystal substrate.
    Type: Grant
    Filed: June 18, 2015
    Date of Patent: July 24, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Shuuhei Higashihara, Makoto Iwai
  • Publication number: 20180202067
    Abstract: An underlying substrate including a seed crystal layer of a group 13 nitride, wherein projections and recesses repeatedly appear in stripe shapes at a principal surface of the seed crystal layer, and the projections have a level difference of 0.3 to 40 ?m and a width of 5 to 100 ?m, and the recesses have a bottom thickness of 2 ?m or more and a width of 50 to 500 ?m.
    Type: Application
    Filed: March 14, 2018
    Publication date: July 19, 2018
    Inventors: Takayuki HIRAO, Makoto IWAI, Katsuhiro IMAI, Takashi YOSHINO
  • Patent number: 10000864
    Abstract: A crystal layer of a nitride of a group 13 element includes a pair of main surfaces. The crystal layer includes high carrier concentration regions having a carrier concentration of 1×1018/cm3 or more and low carrier concentration regions having a carrier concentration of 9×1017/cm3 or less, viewed in a cross section perpendicular to the main surfaces of the crystal layer. Each of the low carrier concentration regions is extended in an elongated shape. The low carrier concentration regions include association parts. The low carrier concentration regions are extended continuously between the pair of the main surfaces.
    Type: Grant
    Filed: June 8, 2017
    Date of Patent: June 19, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Makoto Iwai, Takashi Yoshino
  • Patent number: 9960316
    Abstract: A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0?(an average thickness (?m) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)?10.0 . . . (1); 0.1? a warpage (mm) of said composite substrate×(50/a diameter (mm) of said composite substrate)2?0.6 . . . (2); 1.10?a maximum value (?m) of a thickness of said layer of said nitride of said group 13 element/a minimum value (?m) of said thickness of said layer of said nitride of said group 13 element . . .
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: May 1, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Katsuhiro Imai, Makoto Iwai, Takanao Shimodaira
  • Patent number: 9941442
    Abstract: A crystal substrate is composed of a crystal of a nitride of a group 13 element and has a first main face and a second main face. The crystal substrate includes a low carrier concentration region and a high carrier concentration region both extending between the first main face and second main face. The low carrier concentration region has a carrier concentration of 1018/cm3 or lower and a defect density of 107/cm2 or lower. The high carrier concentration region has a carrier concentration of 1019/cm3 or higher and a defect density of 108/cm2 or higher.
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: April 10, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Makoto Iwai, Takashi Yoshino
  • Patent number: 9882042
    Abstract: Provided are a group 13 nitride composite substrate allowing for the production of a semiconductor device suitable for high-frequency applications while including a conductive GaN substrate, and a semiconductor device produced using this substrate. The group 13 nitride composite substrate includes a base material of an n-conductivity type formed of GaN, a base layer located on the base material, being a group 13 nitride layer having a resistivity of 1×106 ?·cm or more, a channel layer located on the base layer, being a GaN layer having a total impurity density of 1×1017/cm3 or less, and a barrier layer that is located on the channel layer and is formed of a group 13 nitride having a composition AlxInyGa1?x?yN (0?x?1, 0?y?1).
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: January 30, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Yoshitaka Kuraoka, Mikiya Ichimura, Makoto Iwai
  • Publication number: 20170268125
    Abstract: A crystal layer of a nitride of a group 13 element includes a pair of main surfaces. The crystal layer includes high carrier concentration regions having a carrier concentration of 1×1018/cm3 or more and low carrier concentration regions having a carrier concentration of 9×1017/cm3 or less, viewed in a cross section perpendicular to the main surfaces of the crystal layer. Each of the low carrier concentration regions is extended in an elongated shape. The low carrier concentration regions include association parts. The low carrier concentration regions are extended continuously between the pair of the main surfaces.
    Type: Application
    Filed: June 8, 2017
    Publication date: September 21, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Makoto Iwai, Takashi Yoshino
  • Publication number: 20170263810
    Abstract: A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0?(an average thickness (?m) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)?10.0 . . . (1); 0.1? a warpage (mm) of said composite substrate×(50/a diameter (mm) of said composite substrate)20.6 . . . (2); 1.10?a maximum value (?m) of a thickness of said layer of said nitride of said group 13 element/a minimum value (?m) of said thickness of said layer of said nitride of said group 13 element . . .
    Type: Application
    Filed: May 31, 2017
    Publication date: September 14, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Katsuhiro Imai, Makoto Iwai, Takanao Shimodaira
  • Publication number: 20170262647
    Abstract: A mobile storage device includes first and second memory regions in one or more semiconductor memory devices, a positioning system configured to generate positional information indicating a position of the mobile storage device, and a controller. The controller is configured to allow access to the first memory region and prohibit access to the second memory region when the positional information indicates that the position of the mobile storage device is within a first area, and prohibit access to the first memory region and allow access to the second memory region when the positional information indicates that the position of the memory storage device is within a second area, which is different from and does not overlap with the first area.
    Type: Application
    Filed: February 21, 2017
    Publication date: September 14, 2017
    Inventors: Makoto IWAI, Teruji YAMAKAWA, Isao SAKAI, Koki KANDA
  • Publication number: 20170263815
    Abstract: A crystal substrate is composed of a crystal of a nitride of a group 13 element and has a first main face and a second main face. The crystal substrate includes a low carrier concentration region and a high carrier concentration region both extending between the first main face and second main face. The low carrier concentration region has a carrier concentration of 1018/cm3 or lower and a defect density of 107/cm2 or lower. The high carrier concentration region has a carrier concentration of 1019/cm3 or higher and a defect density of 108/cm2 or higher.
    Type: Application
    Filed: May 31, 2017
    Publication date: September 14, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Makoto Iwai, Takashi Yoshino
  • Publication number: 20170170983
    Abstract: In one aspect of the present invention, device information about each slave unit is acquired, each slave unit is grouped from the device information about each slave unit and information about a definition file, and setting information providing for communication operation including generation of a data frame transmitted from a master unit to the slave unit. In generating setting information, the setting information is generated such that the setting information is transmitted in a frame format, in which a data field in each unit in which control data of each slave unit is invalidated due to a transfer abnormality of a data frame is ensured in each group, the data field being included in the data frame in which the control data is stored.
    Type: Application
    Filed: April 28, 2015
    Publication date: June 15, 2017
    Applicant: OMRON Corporation
    Inventors: Makoto IWAI, Takamasa UEDA, Shigenori SAWADA, Hirohito MIZUMOTO, Toshikatsu NAKAMURA
  • Patent number: 9677192
    Abstract: A group 13 nitride crystal substrate according to the present invention is produced by growing a group 13 nitride crystal on a seed-crystal substrate by a flux method, wherein a content of inclusions in the group 13 nitride crystal grown in a region of the seed-crystal substrate except for a circumferential portion of the seed-crystal substrate, the region having an area fraction of 70% relative to an entire area of the seed-crystal substrate, is 10% or less, preferably 2% or less.
    Type: Grant
    Filed: July 15, 2011
    Date of Patent: June 13, 2017
    Assignee: NGK Insulators, Ltd.
    Inventors: Takanao Shimodaira, Katsuhiro Imai, Makoto Iwai, Takayuki Hirao
  • Patent number: 9653649
    Abstract: The maximum value of peak intensities of cathode luminescence of a wavelength corresponding to a band gap of gallium nitride and in a measured visual field of 0.1 mm×0.1 mm is 140 percent or higher of an average value of the peak intensities of the cathode luminescence, provided that the peak intensities of the cathode luminescence are measured on a surface of the gallium nitride substrate.
    Type: Grant
    Filed: October 27, 2015
    Date of Patent: May 16, 2017
    Assignee: NGK INSULATORS, LTD.
    Inventors: Makoto Iwai, Masahiro Sakai, Katsuhiro Imai, Yoshitaka Kuraoka
  • Publication number: 20170075596
    Abstract: A memory system includes a semiconductor storage device that includes a plurality of blocks, and a controller configured to designate a block of the semiconductor storage device as a partial bad block if, after performing a write operation on the block, status information read from the semiconductor storage device indicates that the write operation failed, and read data that is returned when a read operation is performed on data written pursuant to the write operation has errors that are correctable. The controller is configured to manage a partial bad block differently from a bad block.
    Type: Application
    Filed: August 30, 2016
    Publication date: March 16, 2017
    Inventors: Makoto IWAI, Hideaki TSUNASHIMA, Akio OKAZAKI
  • Publication number: 20170069749
    Abstract: Provided are a group 13 nitride composite substrate allowing for the production of a semiconductor device suitable for high-frequency applications while including a conductive GaN substrate, and a semiconductor device produced using this substrate. The group 13 nitride composite substrate includes a base material of an n-conductivity type formed of GaN, a base layer located on the base material, being a group 13 nitride layer having a resistivity of 1×106 ?·cm or more, a channel layer located on the base layer, being a GaN layer having a total impurity density of 1×1017/cm3 or less, and a barrier layer that is located on the channel layer and is formed of a group 13 nitride having a composition AlxInyGa1-x-yN (0?x?1, 0?y?1).
    Type: Application
    Filed: November 18, 2016
    Publication date: March 9, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Yoshitaka Kuraoka, Mikiya Ichimura, Makoto Iwai
  • Publication number: 20170047125
    Abstract: A memory includes first and second select gate transistors, memory cells, a source line, a bit line, a selected word line which is connected to a selected memory cell as a target of a verify reading, a non-selected word line which is connected to a non-selected memory cell except the selected memory cell, a potential generating circuit for generating a selected read potential which is supplied to the selected word line and generating a non-selected read potential larger than the selected read potential, which is supplied to the non-selected wordline, and a control circuit which classifies a threshold voltage of the selected memory cell to one of three groups by verifying which area among three area which are isolated by two values does a cell current of the selected memory cell belong, when the selected read potential is a first value.
    Type: Application
    Filed: October 28, 2016
    Publication date: February 16, 2017
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Makoto IWAI, Hiroshi NAKAMURA
  • Publication number: 20160355945
    Abstract: It is used a crucible containing a flux and a source material, a reaction vessel containing the crucible, an intermediate vessel containing the reaction vessel, and a pressure vessel containing the intermediate vessel and used to fill a gas comprising at least a nitrogen atom. When the flux and the source material are melted by heating to grow the nitride crystal, a vapor of an organic compound is provided in a space outside of the reaction vessel and inside of the intermediate vessel.
    Type: Application
    Filed: August 17, 2016
    Publication date: December 8, 2016
    Applicant: NGK INSULATORS, LTD.
    Inventors: Katsuhiro Imai, Makoto Iwai, Masahiro Sakai, Takanao Shimodaira, Shuhei Higashihara, Takayuki Hirao
  • Patent number: 9514836
    Abstract: A memory includes first and second select gate transistors, memory cells, a source line, a bit line, a selected word line which is connected to a selected memory cell as a target of a verify reading, a non-selected word line which is connected to a non-selected memory cell except the selected memory cell, a potential generating circuit for generating a selected read potential which is supplied to the selected word line, and generating a non-selected read potential larger than the selected read potential, which is supplied to the non-selected word line, and a control circuit which classifies a threshold voltage of the selected memory cell to one of three groups by verifying which area among three area which are isolated by two values does a cell current of the selected memory cell belong, when the selected read potential is a first value.
    Type: Grant
    Filed: October 19, 2015
    Date of Patent: December 6, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Makoto Iwai, Hiroshi Nakamura
  • Publication number: 20160300980
    Abstract: In a substrate having a gallium nitride layer, surface damage after surface treatment of the gallium nitride layer is reduced and quality of a functional device formed thereon is improved. A substrate 4 having at least a gallium nitride layer 4 is provided. A plasma etching system equipped with an inductively coupled plasma generating system is used and a fluorine-based gas is introduced at a standardized direct current bias potential of ?10V/cm2 or higher to subject a surface 3a of the gallium nitride layer to dry etching treatment.
    Type: Application
    Filed: June 23, 2016
    Publication date: October 13, 2016
    Applicant: NGK INSULATORS, LTD.
    Inventors: Shuhei Higashihara, Makoto Iwai, Katsuhiro Imai
  • Patent number: 9384848
    Abstract: A memory includes first and second select gate transistors, memory cells, a source line, a bit line, a selected word line which is connected to a selected memory cell as a target of a verify reading, a non-selected word line which is connected to a non-selected memory cell except the selected memory cell, a potential generating circuit for generating a selected read potential which is supplied to the selected word line, and generating a non-selected read potential larger than the selected read potential, which is supplied to the non-selected word line, and a control circuit which classifies a threshold voltage of the selected memory cell to one of three groups by verifying which area among three area which are isolated by two values does a cell current of the selected memory cell belong, when the selected read potential is a first value.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: July 5, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Makoto Iwai, Hiroshi Nakamura