Patents by Inventor Toru Takayama

Toru Takayama 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: 20230402821
    Abstract: A nitride semiconductor light-emitting element includes: an N-type cladding layer; an N-side first guide layer; an N-side second guide layer; an active layer including a well layer and a barrier layer; and a P-type cladding layer. The band gap energy of the barrier layer is larger than the band gap energy of the N-side second guide layer. The band gap energy of the N-side second guide layer is smaller than the band gap energy of the N-side first guide layer. The band gap energy of the N-side first guide layer is smaller than the band gap energy of the N-type cladding layer. The cladding layers, the guide layers, and the barrier layer each comprise a nitride semiconductor including Al.
    Type: Application
    Filed: August 9, 2023
    Publication date: December 14, 2023
    Inventors: Toru TAKAYAMA, Shinji YOSHIDA
  • Publication number: 20230387352
    Abstract: A nitride semiconductor light-emitting element includes a semiconductor stack. The semiconductor stack includes an N-type first cladding layer, an N-side guide layer, an active layer, a P-side first guide layer, a P-side second guide layer, and a P-type cladding layer. The band gap energy of the P-side second guide layer is larger than the band gap energy of the N-side guide layer. The band gap energy of the N-side guide layer is larger than or equal to the band gap energy of the P-side first guide layer. Tn1<Tp1+Tp2, where Tp1 is the thickness of the P-side first guide layer, Tp2 is the thickness of the P-side second guide layer, and Tn1 is the thickness of the N-side guide layer.
    Type: Application
    Filed: August 9, 2023
    Publication date: November 30, 2023
    Inventor: Toru TAKAYAMA
  • Publication number: 20230140710
    Abstract: A nitride-based semiconductor light-emitting element includes a semiconductor stack body that includes: an N-type first cladding layer; an N-side guide layer; an active layer that includes a well layer and a barrier layer; a P-side guide layer; and a P-type cladding layer. Band gap energy of the P-side guide layer monotonically increases with an increase in distance from the active layer. An average of the band gap energy of the P-side guide layer is greater than or equal to an average of band gap energy of the N-side guide layer. Band gap energy of the barrier layer is less than or equal to a smallest value of the band gap energy of the N-side guide layer and a smallest value of the band gap energy of the P-side guide layer. A thickness of the P-side guide layer is greater than a thickness of the N-side guide layer.
    Type: Application
    Filed: December 8, 2022
    Publication date: May 4, 2023
    Inventor: Toru TAKAYAMA
  • Publication number: 20230021325
    Abstract: A semiconductor laser device includes an N-type cladding layer, an active layer, and a P-type cladding layer. The active layer includes a well layer, a P-side first barrier layer above the well layer, and a P-side second barrier layer above the P-side first barrier layer. The P-side second barrier layer has an AI composition ratio higher than an AI composition ratio of the P-side first barrier layer. The P-side second barrier layer has band gap energy greater than band gap energy of the P-side first barrier layer. The semiconductor laser device has an end face window structure in which band gap energy of a portion of the well layer in a vicinity of an end face that emits the laser light is greater than band gap energy of a central portion of the well layer in a resonator length direction.
    Type: Application
    Filed: September 28, 2022
    Publication date: January 26, 2023
    Inventors: Toru TAKAYAMA, Togo NAKATANI, Hiroki NAGAI, Takashi YUMOTO, Takeshi YOKOYAMA, Shoichi TAKASUKA
  • Publication number: 20220285918
    Abstract: A semiconductor light-emitting element includes: a substrate; an n-type clad layer above the substrate; an active layer above the n-type clad layer; and a p-type clad layer above the active layer. The active layer includes: a well layer; an n-side first barrier layer on an n-type clad layer side of the well layer; and a p-side barrier layer on a p-type clad layer side of the well layer. The p-side barrier layer comprises In. The n-side first barrier layer has an In composition ratio lower than an In composition ratio of the p-side barrier layer. The n-side first barrier layer has a band gap energy smaller than a band gap energy of the p-side barrier layer.
    Type: Application
    Filed: May 16, 2022
    Publication date: September 8, 2022
    Inventors: Toru TAKAYAMA, Takashi YUMOTO, Takeshi YOKOYAMA, Tougo NAKATANI, Shoichi TAKASUKA
  • Patent number: 11437780
    Abstract: A semiconductor laser device lases in a multiple transverse mode and includes a stacked structure where a first conductivity-side semiconductor layer, an active layer, and a second conductivity-side semiconductor layer are stacked above a substrate. The second conductivity-side semiconductor layer includes a current block layer having an opening that delimits a current injection region. Side faces as a pair are formed in portions of the stacked structure that range from part of the first conductivity-side semiconductor layer to the second conductivity-side semiconductor layer. The active layer has a second width greater than a first width of the opening. The side faces in at least part of the first conductivity-side semiconductor layer are inclined to the substrate. A maximum intensity position in a light distribution of light guided in the stacked structure, in a direction of the normal to the substrate, is within the first conductivity-side semiconductor layer.
    Type: Grant
    Filed: September 11, 2019
    Date of Patent: September 6, 2022
    Assignee: NUVOTON TECHNOLOGY CORPORATION JAPAN
    Inventors: Norio Ikedo, Tougo Nakatani, Takahiro Okaguchi, Takeshi Yokoyama, Tomohito Yabushita, Toru Takayama
  • Patent number: 11422423
    Abstract: A structure for preventing deteriorations of a light-emitting device and retaining sufficient capacitor elements (condenser) required by each pixel is provided. A first passivation film, a second metal layer, a flattening film, a barrier film, and a third metal layer are stacked in this order over a transistor. A side face of a first opening provided with the flattening film is covered by the barrier film, a second opening is formed inside the first opening, and a third metal layer is connected to a semiconductor via the first opening and the second opening. A capacitor element that is formed of a lamination of a semiconductor of a transistor, a gate insulating film, a gate electrode, the first passivation film, and the second metal layer is provided.
    Type: Grant
    Filed: October 30, 2019
    Date of Patent: August 23, 2022
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Toru Takayama, Satoshi Murakami, Hajime Kimura
  • Patent number: 11322908
    Abstract: A nitride light emitter includes: a nitride semiconductor light-emitting element including an AlxGa1-xN substrate (0?x?1) and a multilayer structure above the AlxGa1-xN substrate; and a submount substrate on which the nitride semiconductor light-emitting element is mounted. The multilayer structure includes a first clad layer of a first conductivity type, a first light guide layer, a quantum-well active layer, a second light guide layer, and a second clad layer of a second conductivity type which are stacked sequentially from the AlxGa1-xN substrate. The multilayer structure and submount substrate are opposed to each other. The submount substrate comprises diamond. The nitride semiconductor light-emitting element has a concave warp on a surface closer to the AlxGa1-xN substrate.
    Type: Grant
    Filed: October 31, 2019
    Date of Patent: May 3, 2022
    Assignee: NUVOTON TECHNOLOGY CORPORATION JAPAN
    Inventors: Toru Takayama, Tohru Nishikawa, Tougo Nakatani, Katsuya Samonji, Takashi Kano, Shinji Ueda
  • Patent number: 11309688
    Abstract: In a method for manufacturing a nitride semiconductor light-emitting element by splitting a semiconductor layer stacked substrate including a semiconductor layer stacked body with a plurality of waveguides extending along the Y-axis to fabricate a bar-shaped substrate, and splitting the bar-shaped substrate along a lengthwise split line to fabricate an individual element, the waveguide in the individual element has different widths at one end portion and the other end portion and the center line of the waveguide is located off the center of the individual element along the X-axis, and in the semiconductor layer stacked substrate including a first element forming region and a second element forming region which are adjacent to each other along the X-axis, two lengthwise split lines sandwiching the first element forming region and two lengthwise split lines sandwiching the second element forming region are misaligned along the X-axis.
    Type: Grant
    Filed: September 26, 2019
    Date of Patent: April 19, 2022
    Assignee: NUVOTON TECHNOLOGY CORPORATION JAPAN
    Inventors: Daisuke Ikeda, Gen Shimizu, Hideo Kitagawa, Toru Takayama, Masayuki Ono, Katsuya Samonji, Osamu Tomita, Satoko Kawasaki
  • Patent number: 11296131
    Abstract: There is provided a peeling method capable of preventing a damage to a layer to be peeled. Thus, not only a layer to be peeled having a small area but also a layer to be peeled having a large area can be peeled over the entire surface at a high yield. Processing for partially reducing contact property between a first material layer (11) and a second material layer (12) (laser light irradiation, pressure application, or the like) is performed before peeling, and then peeling is conducted by physical means. Therefore, sufficient separation can be easily conducted in an inner portion of the second material layer (12) or an interface thereof.
    Type: Grant
    Filed: January 2, 2020
    Date of Patent: April 5, 2022
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toru Takayama, Junya Maruyama, Shunpei Yamazaki
  • Publication number: 20220085324
    Abstract: To realize a high-performance liquid crystal display device or light-emitting element using a plastic film. A CPU is formed over a first glass substrate and then, separated from the first substrate. A pixel portion having a light-emitting element is formed over a second glass substrate, and then, separated from the second substrate. The both are bonded to each other. Therefore, high integration can be achieved. Further, in this case, the separated layer including the CPU serves also as a sealing layer of the light-emitting element.
    Type: Application
    Filed: November 29, 2021
    Publication date: March 17, 2022
    Inventors: Toru TAKAYAMA, Junya MARUYAMA, Yumiko OHNO
  • Patent number: 11196020
    Abstract: To realize a high-performance liquid crystal display device or light-emitting element using a plastic film. A CPU is formed over a first glass substrate and then, separated from the first substrate. A pixel portion having a light-emitting element is formed over a second glass substrate, and then, separated from the second substrate. The both are bonded to each other. Therefore, high integration can be achieved. Further, in this case, the separated layer including the CPU serves also as a sealing layer of the light-emitting element.
    Type: Grant
    Filed: June 29, 2020
    Date of Patent: December 7, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toru Takayama, Junya Maruyama, Yumiko Ohno
  • Publication number: 20210359163
    Abstract: A semiconductor light-emitting device includes: a first semiconductor layer containing a first conductivity type nitride semiconductor; an active layer containing a nitride semiconductor including Ga or In; an electron barrier layer containing a nitride semiconductor including at least Al, and being of a second conductivity type; and a second semiconductor layer containing a second conductivity type nitride semiconductor. The electron barrier layer includes a region where an Al composition ratio increases monotonically toward the second semiconductor layer. A maximum impurity concentration position of the second conductivity type in the electron barrier layer is located between an interface on an active layer side of the electron barrier layer and an intermediate position between a maximum Al composition ratio position of the electron barrier layer in the region and an interface on an active layer side of the electron barrier layer.
    Type: Application
    Filed: July 29, 2021
    Publication date: November 18, 2021
    Inventors: Toru TAKAYAMA, Shinji YOSHIDA, Kunimasa TAKAHASHI
  • Publication number: 20210298148
    Abstract: A DC-DC power supply according to an embodiment includes a voltage converter, a first switching element, a second switching element, and a controller. The voltage converter converts an input voltage into a first voltage. The first switching element performs switching according to a pulse signal to thereby intermit the first voltage applied to one end of a load. One end of the second switching element is connected to the other end of the load. The second switching element performs an ON/OFF operation at a predetermined advance time with respect to the first switching element. The controller controls, based on a voltage at the other end of the second switching element in a one-voltage holder, the first voltage output by the voltage converter.
    Type: Application
    Filed: September 4, 2020
    Publication date: September 23, 2021
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yoichi TOKAI, Toru TAKAYAMA
  • Patent number: 11070028
    Abstract: A semiconductor light emitting element includes: a GaN substrate; a first semiconductor layer located above the GaN substrate and including a nitride semiconductor of a first conductivity type; an active layer located above the first semiconductor layer and including a nitride semiconductor including Ga or In; an electron barrier layer located above the active layer and including a nitride semiconductor including Al; and a second semiconductor layer located above the electron barrier layer and including a nitride semiconductor of a second conductivity type. The electron barrier layer includes: a first region having an Al composition ratio changing at a first change rate; and a second region having an Al composition ratio changing at a second change rate larger than the first change rate. In the first second regions, the Al composition ratio monotonically increases at the first change rate in the direction from the active layer toward second semiconductor layer.
    Type: Grant
    Filed: September 10, 2020
    Date of Patent: July 20, 2021
    Assignee: NUVOTON TECHNOLOGY CORPORATION JAPAN
    Inventors: Toru Takayama, Shinji Yoshida, Kunimasa Takahashi
  • Patent number: 10985533
    Abstract: A semiconductor laser device includes: a first semiconductor layer on a first conductivity side; a second semiconductor layer on the first conductivity side; an active layer; a third semiconductor layer on a second conductivity side different from the first conductivity side; and a fourth semiconductor layer on the second conductivity side. Eg2<Eg3 is satisfied, where Eg2 and Eg3 denote maximum values of band gap energy of the second semiconductor layer and the third semiconductor layer, respectively. The third semiconductor layer includes a first region layer in which band gap energy monotonically decreases toward the fourth semiconductor layer. N2>N3 is satisfied, where N2 denotes an impurity concentration of the second semiconductor layer, and N3 denotes an impurity concentration of the third semiconductor layer.
    Type: Grant
    Filed: December 20, 2018
    Date of Patent: April 20, 2021
    Assignee: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.
    Inventors: Tougo Nakatani, Takahiro Okaguchi, Norio Ikedo, Takeshi Yokoyama, Tomohito Yabushita, Toru Takayama, Shoichi Takasuka
  • Patent number: 10971897
    Abstract: A semiconductor laser device includes: a first conductivity side semiconductor layer, an active layer; and a second conductivity side semiconductor layer. The second conductivity side semiconductor layer includes a first semiconductor layer and a second semiconductor layer, the first semiconductor layer being closer to the active layer than the second semiconductor layer is. The second semiconductor layer defines a width of a current injection region for injecting current into an optical waveguide. The current injection region includes a width varying region in which a width varies. S1>S2, where S1 denotes a width of the width varying region on a front end face side, and S2 denotes a width of the width varying region on a rear end face side.
    Type: Grant
    Filed: December 27, 2018
    Date of Patent: April 6, 2021
    Assignee: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.
    Inventors: Norio Ikedo, Tougo Nakatani, Takahiro Okaguchi, Takeshi Yokoyama, Tomohito Yabushita, Toru Takayama
  • Patent number: 10957723
    Abstract: To provide a semiconductor device in which a layer to be peeled is attached to a base having a curved surface, and a method of manufacturing the same, and more particularly, a display having a curved surface, and more specifically a light-emitting device having a light emitting element attached to a base with a curved surface. A layer to be peeled, which contains a light emitting element furnished to a substrate using a laminate of a first material layer which is a metallic layer or nitride layer, and a second material layer which is an oxide layer, is transferred onto a film, and then the film and the layer to be peeled are curved, to thereby produce a display having a curved surface.
    Type: Grant
    Filed: April 14, 2020
    Date of Patent: March 23, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toru Takayama, Junya Maruyama, Yuugo Goto, Hideaki Kuwabara, Shunpei Yamazaki
  • Publication number: 20200412101
    Abstract: A semiconductor light emitting element includes: a GaN substrate; a first semiconductor layer located above the GaN substrate and including a nitride semiconductor of a first conductivity type; an active layer located above the first semiconductor layer and including a nitride semiconductor including Ga or In; an electron barrier layer located above the active layer and including a nitride semiconductor including Al; and a second semiconductor layer located above the electron barrier layer and including a nitride semiconductor of a second conductivity type. The electron barrier layer includes: a first region having an Al composition ratio changing at a first change rate; and a second region having an Al composition ratio changing at a second change rate larger than the first change rate. In the first second regions, the Al composition ratio monotonically increases at the first change rate in the direction from the active layer toward second semiconductor layer.
    Type: Application
    Filed: September 10, 2020
    Publication date: December 31, 2020
    Inventors: Toru TAKAYAMA, Shinji YOSHIDA, Kunimasa TAKAHASHI
  • Publication number: 20200328372
    Abstract: To realize a high-performance liquid crystal display device or light-emitting element using a plastic film. A CPU is formed over a first glass substrate and then, separated from the first substrate. A pixel portion having a light-emitting element is formed over a second glass substrate, and then, separated from the second substrate. The both are bonded to each other. Therefore, high integration can be achieved. Further, in this case, the separated layer including the CPU serves also as a sealing layer of the light-emitting element.
    Type: Application
    Filed: June 29, 2020
    Publication date: October 15, 2020
    Inventors: Toru TAKAYAMA, Junya MARUYAMA, Yumiko OHNO