Patents by Inventor Ryota Takemura

Ryota Takemura 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: 11978812
    Abstract: A waveguide photodetector includes a first contact layer of a first conductivity type, a waveguide layer, and a second contact layer of a second conductivity type that are sequentially formed on the semiconductor substrate. The waveguide layer includes a first cladding layer of the first conductivity type disposed on a side of the first contact layer, a second cladding layer of the second conductivity type disposed on a side of the second contact layer, and the core layer disposed between the first cladding layer and the second cladding layer. The core layer includes a light absorption layer and an impurity-doped light absorption layer that has a higher concentration of a p-type impurity than that of the light absorption layer and is disposed on a side of a light incident face.
    Type: Grant
    Filed: February 26, 2020
    Date of Patent: May 7, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventor: Ryota Takemura
  • Patent number: 11862747
    Abstract: A semiconductor light-receiving element (50) is a semiconductor light-receiving element in which a multi-plication layer (2), an electric-field control layer (3), a light absorption layer (4) and a window layer (5) are sequentially formed on a semiconductor substrate (1), and a p-type region (6) is formed in the window layer (5). The p-type region (6) has a first p-type portion (14) and a second p-type portion (15) whose current multiplication factor due to light incidence is larger than that of the first p-type portion (14). The first p-type portion (14) is formed as a central portion of the p-type region (6), the central portion including a central axis (21c) perpendicular to the semiconductor substrate (1), and the second p-type portion (15) is formed on an outer periphery of the central portion in a radial direction about the central axis (21c).
    Type: Grant
    Filed: April 5, 2019
    Date of Patent: January 2, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryota Takemura, Matobu Kikuchi
  • Publication number: 20230178666
    Abstract: A ridge structure (7) including at least a light-absorbing layer (4) is provided on a semiconductor substrate (1). A semiconductor embedding layer (8) has a refractive index lower than that of the light-absorbing layer (4) and embeds a side surface of the light-absorbing layer (4). A semiconductor layer (13) has a refractive index between that of the light-absorbing layer (4) and that of the semiconductor embedding layer (8) and is provided between the side surface of the light-absorbing layer (4) and the semiconductor embedding layer (8). The refractive index of the semiconductor layer (13) is n3, a wavelength of the incident light (15) is ?, a thickness of the semiconductor layer (13) in a lateral direction is in a range of-30% to +20% of ?/(4xn3).
    Type: Application
    Filed: October 9, 2020
    Publication date: June 8, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventor: Ryota TAKEMURA
  • Publication number: 20230055105
    Abstract: A waveguide photodetector includes a first contact layer of a first conductivity type, a waveguide layer, and a second contact layer of a second conductivity type that are sequentially formed on the semiconductor substrate. The waveguide layer includes a first cladding layer of the first conductivity type disposed on a side of the first contact layer, a second cladding layer of the second conductivity type disposed on a side of the second contact layer, and the core layer disposed between the first cladding layer and the second cladding layer. The core layer includes a light absorption layer and an impurity-doped light absorption layer that has a higher concentration of a p-type impurity than that of the light absorption layer and is disposed on a side of a light incident face.
    Type: Application
    Filed: February 26, 2020
    Publication date: February 23, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventor: Ryota TAKEMURA
  • Patent number: 11329179
    Abstract: A multiplication layer on a semiconductor substrate of n-type contains Al atoms. An electric field control layer on the multiplication layer is of p-type, and includes a high-concentration area, and a low-concentration area lower in impurity concentration than the high-concentration area which is formed outside the high-concentration area. An optical absorption layer on the electric field control layer is lower in impurity concentration than the high-concentration area. A window layer of n-type formed on the optical absorption layer is larger in band gap than the optical absorption layer. A light-receiving area of p-type is formed apart from an outer edge of the window layer, and at least partly faces the high-concentration area through the window layer and the optical absorption layer. The guard ring area of p-type which the window layer separates from the light-receiving area penetrates through the window layer to extend into the optical absorption layer.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: May 10, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryota Takemura, Eitaro Ishimura, Harunaka Yamaguchi
  • Publication number: 20220109080
    Abstract: A semiconductor light-receiving element (50) is a semiconductor light-receiving element in which a multi-plication layer (2), an electric-field control layer (3), a light absorption layer (4) and a window layer (5) are sequentially formed on a semiconductor substrate (1), and a p-type region (6) is formed in the window layer (5). The p-type region (6) has a first p-type portion (14) and a second p-type portion (15) whose current multiplication factor due to light incidence is larger than that of the first p-type portion (14). The first p-type portion (14) is formed as a central portion of the p-type region (6), the central portion including a central axis (21c) perpendicular to the semiconductor substrate (1), and the second p-type portion (15) is formed on an outer periphery of the central portion in a radial direction about the central axis (21c).
    Type: Application
    Filed: April 5, 2019
    Publication date: April 7, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryota TAKEMURA, Matobu KIKUCHI
  • Publication number: 20200203544
    Abstract: A multiplication layer on a semiconductor substrate of n-type contains Al atoms. An electric field control layer on the multiplication layer is of p-type, and includes a high-concentration area, and a low-concentration area lower in impurity concentration than the high-concentration area which is formed outside the high-concentration area. An optical absorption layer on the electric field control layer is lower in impurity concentration than the high-concentration area. A window layer of n-type formed on the optical absorption layer is larger in band gap than the optical absorption layer. A light-receiving area of p-type is formed apart from an outer edge of the window layer, and at least partly faces the high-concentration area through the window layer and the optical absorption layer. The guard ring area of p-type which the window layer separates from the light-receiving area penetrates through the window layer to extend into the optical absorption layer.
    Type: Application
    Filed: September 15, 2017
    Publication date: June 25, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryota TAKEMURA, Eitaro ISHIMURA, Harunaka YAMAGUCHI
  • Patent number: 10553742
    Abstract: A substrate has a front surface and a back surface opposite from the front surface. An n-type layer, a multiplication layer, a p-type electric field control layer, a light absorption layer, and a window layer are layered in order on the front surface. A p-type region is provided in part of the window layer. An anode electrode is provided on the p-type region and connected to the p-type region. An anode pad and a cathode pad are provided on the back surface. First and second connecting holes penetrates the substrate. A third connecting hole penetrates from the window layer to the n-type layer. The cathode pad is electrically connected to the n-type layer via the first connecting hole. The anode pad is electrically connected to the anode electrode via the second and third connecting holes. A light-receiving region is provided on the back surface.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: February 4, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryota Takemura, Nobuo Ohata, Yoshifumi Sasahata, Kazuki Yamaji
  • Publication number: 20190296175
    Abstract: A substrate has a front surface and a back surface opposite from the front surface. An n-type layer, a multiplication layer, a p-type electric field control layer, a light absorption layer, and a window layer are layered in order on the front surface. A p-type region is provided in part of the window layer. An anode electrode is provided on the p-type region and connected to the p-type region. An anode pad and a cathode pad are provided on the back surface. First and second connecting holes penetrates the substrate. A third connecting hole penetrates from the window layer to the n-type layer. The cathode pad is electrically connected to the n-type layer via the first connecting hole. The anode pad is electrically connected to the anode electrode via the second and third connecting holes. A light-receiving region is provided on the back surface.
    Type: Application
    Filed: October 28, 2016
    Publication date: September 26, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryota TAKEMURA, Nobuo OHATA, Yoshifumi SASAHATA, Kazuki YAMAJI
  • Patent number: 9426656
    Abstract: An on-vehicle device is configured to be able to communicate with a mobile device, and includes a reception unit, an interruption detection unit, a determination unit, and a display control unit. The reception unit receives image information transmitted from a particular mobile device which is a mobile device with which communication is established. The interruption detection unit detects that reception of the image information is interrupted. The determination unit determines whether or not the transmission device which transmits the image information is the particular mobile device, when the reception unit receives image information again after interruption of the reception is detected. The display control unit stops displaying the image information transmitted from the transmission device on a display device when the transmission device is determined not to be the particular mobile device.
    Type: Grant
    Filed: September 3, 2013
    Date of Patent: August 23, 2016
    Assignees: FUJITSU TEN LIMITED, HONDA MOTOR CO., LTD.
    Inventors: Ryota Takemura, Takanori Fujiwara, Atsuyuki Suzuki, Junichi Hirose
  • Patent number: 9406830
    Abstract: A semiconductor light-receiving device includes: a substrate; a p-type conductive layer, a light absorption layer having a smaller bandgap than that of incident light, a multiplication layer producing avalanche multiplication, and an n-type window layer laminated in that order on the substrate; an n-type conductive layer in a region of part of the n-type window layer; and a first p-type conductive region in a region of the n-type window layer that is not in contact with the n-type conductive layer, wherein the first p-type conductive region does not reach the multiplication layer and is not in contact with any electrode to which power is supplied from outside.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: August 2, 2016
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Ryota Takemura, Masaharu Nakaji, Kazuki Yamaji
  • Patent number: 9257577
    Abstract: A light receiving element includes a substrate of a first conduction type, a light absorbing layer of the first conduction type formed on the substrate, a diffusion layer of a second conduction type formed on a portion of the light absorbing layer, a window layer of the first conduction type formed on the light absorbing layer so as to surround the diffusion layer and having a bandgap larger than that of the light absorbing layer, an anode electrode formed on the diffusion layer, and a cathode electrode provided on the substrate so as to contact the substrate without contacting each of the window layer and the light absorbing layer, wherein a groove is formed which surrounds a boundary between the diffusion layer and the window layer as viewed in plan and extends through the window layer and the light absorbing layer as viewed in section.
    Type: Grant
    Filed: April 9, 2015
    Date of Patent: February 9, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Matobu Kikuchi, Masaharu Nakaji, Ryota Takemura, Kazuki Yamaji
  • Publication number: 20160020339
    Abstract: A light receiving element includes a substrate of a first conduction type, a light absorbing layer of the first conduction type formed on the substrate, a diffusion layer of a second conduction type formed on a portion of the light absorbing layer, a window layer of the first conduction type formed on the light absorbing layer so as to surround the diffusion layer and having a bandgap larger than that of the light absorbing layer, an anode electrode formed on the diffusion layer, and a cathode electrode provided on the substrate so as to contact the substrate without contacting each of the window layer and the light absorbing layer, wherein a groove is formed which surrounds a boundary between the diffusion layer and the window layer as viewed in plan and extends through the window layer and the light absorbing layer as viewed in section.
    Type: Application
    Filed: April 9, 2015
    Publication date: January 21, 2016
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Matobu KIKUCHI, Masaharu NAKAJI, Ryota TAKEMURA, Kazuki YAMAJI
  • Publication number: 20150223064
    Abstract: An on-vehicle device is configured to be able to communicate with a mobile device, and includes a reception unit, an interruption detection unit, a determination unit, and a display control unit. The reception unit receives image information transmitted from a particular mobile device which is a mobile device with which communication is established. The interruption detection unit detects that reception of the image information is interrupted. The determination unit determines whether or not the transmission device which transmits the image information is the particular mobile device, when the reception unit receives image information again after interruption of the reception is detected. The display control unit stops displaying the image information transmitted from the transmission device on a display device when the transmission device is determined not to be the particular mobile device.
    Type: Application
    Filed: September 3, 2013
    Publication date: August 6, 2015
    Inventors: Ryota Takemura, Takanori Fujiwara, Atsuyuki Suzuki, Junichi Hirose
  • Publication number: 20140131827
    Abstract: An i-type AlInAs avalanche multiplication layer is grown on an n-type InP substrate. A p-type AlInAs electric field reduction layer is grown on the i-type AlInAs avalanche multiplication layer. Transition layers are grown to cover the top surface of the electric field reduction layer. After the covering of the top surface of the electric field reduction layer by the transition layers, the temperature of the growth process is increased and an n?-type InGaAs light absorption layer is grown on the transition layer at a temperature higher than the growth temperature of the electric field reduction layer. The growth temperature of the transition layers is lower than that of the n?-type InGaAs light absorption layer. The transition layers have higher resistance to surface defects than the electric field reduction layer at temperatures higher than the growth temperature of the electric field reduction layer.
    Type: Application
    Filed: July 18, 2013
    Publication date: May 15, 2014
    Inventors: Harunaka Yamaguchi, Ryota Takemura
  • Publication number: 20130299936
    Abstract: An avalanche photodiode includes a substrate; an avalanche multiplying layer, a p-type electric field controlling layer, a light-absorbing layer, and a window layer sequentially laminated on the substrate. A p-type region is present in parts of the window layer and the light-absorbing layer. Carbon is the dopant of the electric field controlling layer. Zn is the dopant of the p-type region. A bottom face of the p-type region is closer to the substrate than is an interface between the light-absorbing layer and the window layer.
    Type: Application
    Filed: January 21, 2013
    Publication date: November 14, 2013
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryota Takemura, Eitaro Ishimura
  • Patent number: 8399945
    Abstract: A semiconductor light detecting element includes: a semiconductor substrate; and a distributed Bragg reflector layer of a first conductivity type, an optical absorption layer, and a semiconductor layer of a second conductivity type, sequentially laminated on the semiconductor substrate. The distributed Bragg reflector layer includes first and second alternately laminated semiconductor layers with different band-gap wavelengths, sandwiching the wavelength of detected incident light. The sum of thicknesses a first and a second semiconductor layer is approximately one-half the wavelength of the incident light detected.
    Type: Grant
    Filed: May 20, 2010
    Date of Patent: March 19, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masaharu Nakaji, Ryota Takemura
  • Publication number: 20120299144
    Abstract: A semiconductor light-detecting device includes: a semi-insulating substrate; and n light-detecting elements (n is a natural number equal to or larger than 4) electrically isolated from each other and on the semi-insulating substrate. Each light-detecting element includes a conductive layer of a first conductivity type, a light absorption layer, a window layer, and an impurity diffusion region of a second conductivity type, which are laminated, one on another, on the semi-insulating substrate. The light absorption layer is a photoelectrical converter. The impurity diffusion region is located in part of the window layer and serves as a light-detecting section. A part of the conductive layer and the light absorption layer use the same material. The n light-detecting elements are not all located on a common straight line.
    Type: Application
    Filed: December 29, 2011
    Publication date: November 29, 2012
    Applicant: MITSHUBISHI ELECTRIC CORPORATION
    Inventors: Masaharu NAKAJI, Ryota TAKEMURA
  • Publication number: 20110073973
    Abstract: A semiconductor light detecting element includes: a semiconductor substrate; and a distributed Bragg reflector layer of a first conductivity type, an optical absorption layer, and a semiconductor layer of a second conductivity type, sequentially laminated on the semiconductor substrate. The distributed Bragg reflector layer includes first and second alternately laminated semiconductor layers with different band-gap wavelengths, sandwiching the wavelength of detected incident light. The sum of thicknesses a first and a second semiconductor layer is approximately one-half the wavelength of the incident light detected.
    Type: Application
    Filed: May 20, 2010
    Publication date: March 31, 2011
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masaharu Nakaji, Ryota Takemura