Patents by Inventor Hideki Yagi

Hideki Yagi 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: 20140021160
    Abstract: A method for manufacturing an optical semiconductor device includes the steps of preparing a substrate product including a semiconductor layer, a mesa structure, and a protective layer; forming a buried layer composed of a resin on the substrate product; forming a first opening in the buried layer on the mesa structure; forming a second opening in the buried layer on the semiconductor layer; exposing the mesa structure and the semiconductor layer by etching the protective layer; forming a first electrode in the first opening; and forming a second electrode in the second opening. The step of forming the second opening includes a first etching step including etching the buried layer using a first resist mask for forming a recess and a second etching step including etching the buried layer using a second resist mask having an opening pattern which has an opening width not smaller than that of the recess.
    Type: Application
    Filed: July 5, 2013
    Publication date: January 23, 2014
    Inventors: Takamitsu KITAMURA, Hideki YAGI
  • Patent number: 8617969
    Abstract: A method for producing a semiconductor optical device includes the steps of growing a semiconductor stacked layer including an etch stop layer and a plurality of semiconductor layers on a major surface of a substrate; forming a mask layer on a top surface of the semiconductor stacked layer so that a tip portion of each of protrusions that protrude from the top surface among protrusions generated in the step of growing the semiconductor stacked layer is exposed; etching the protrusion by wet etching using the mask layer; after etching the protrusion by wet etching, removing the protrusion by dry etching; and removing the mask layer from the top surface, after removing the protrusion by dry etching.
    Type: Grant
    Filed: June 22, 2012
    Date of Patent: December 31, 2013
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Kenji Sakurai, Hideki Yagi, Hiroyuki Yoshinaga
  • Publication number: 20130322808
    Abstract: A semiconductor Mach-Zehnder modulator includes a substrate having a main surface including first, second and third regions sequentially arranged along a direction; a waveguide mesa including first and second waveguide arms provided on the second region, first and second optical couplers provided on the first and third regions, respectively; a first semiconductor protective layer provided on side surfaces of the first and second waveguide arms; a buried layer provided on side surfaces of the waveguide mesa and on the main surface, the buried layer including a material having a dielectric constant lower than that of the first protective layer; and first and second upper electrodes provided on the first and second waveguide arms, respectively. The first and second optical couplers are connected to the first and second waveguide arms. Above the second region, the buried layer is provided on the first protective layer.
    Type: Application
    Filed: May 22, 2013
    Publication date: December 5, 2013
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventor: Hideki YAGI
  • Patent number: 8450128
    Abstract: A method for producing a semiconductor optical device includes the steps of forming a semiconductor region including a ridge structure on a substrate; forming an insulating film on the semiconductor region; forming a non-photosensitive resin region on the insulating film, forming a first mask that defines a scribe area; forming the scribe area by etching using the first mask; after removing the first mask, forming an insulating layer by etching the insulating film, forming an electrode on the ridge structure and the non-photosensitive resin region to produce a substrate product; forming a scribe line on a surface of the semiconductor region in the scribe area of the substrate product; and cutting the product along the scribe line to form a semiconductor laser bar.
    Type: Grant
    Filed: October 7, 2011
    Date of Patent: May 28, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideki Yagi, Hiroyuki Yoshinaga
  • Publication number: 20130071129
    Abstract: A multi-channel optical waveguide receiver includes an optical input port; an optical branching unit; light-receiving elements having bias electrodes and signal electrodes; optical waveguides being optically coupled between the optical branching unit and the light-receiving elements; capacitors electrically connected between the bias electrodes and a reference potential, the capacitors and the bias electrodes being connected through interconnection patterns; and a signal amplifier including input electrodes. The optical branching unit, the light-receiving elements, the optical waveguides, and the capacitors are formed on a single substrate, the substrate having an edge extending in a first direction. The signal amplifier and the substrate are arranged in a second direction crossing the first direction. The input electrodes and the signal electrodes are arranged along the edge of the substrate.
    Type: Application
    Filed: September 11, 2012
    Publication date: March 21, 2013
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yoshihiro YONEDA, Hideki YAGI, Naoko INOUE
  • Publication number: 20130012001
    Abstract: A method for producing a semiconductor optical device includes the steps of growing a semiconductor stacked layer including an etch stop layer and a plurality of semiconductor layers on a major surface of a substrate; forming a mask layer on a top surface of the semiconductor stacked layer so that a tip portion of each of protrusions that protrude from the top surface among protrusions generated in the step of growing the semiconductor stacked layer is exposed; etching the protrusion by wet etching using the mask layer; after etching the protrusion by wet etching, removing the protrusion by dry etching; and removing the mask layer from the top surface, after removing the protrusion by dry etching.
    Type: Application
    Filed: June 22, 2012
    Publication date: January 10, 2013
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Kenji SAKURAI, Hideki YAGI, Hiroyuki YOSHINAGA
  • Publication number: 20130001643
    Abstract: A process to form a photodiode (PD) with the waveguide structure is disclosed. The PD processes thereby reduces a scattering of the parasitic resistance thereof. The process includes steps to form a PD mesa stripe, to bury the PD mesa stripe by the waveguide region, to etch the PD mesa stripe and the waveguide region to form the waveguide mesa stripe. In the etching, the lower contact layer plays a role of the etching stopper.
    Type: Application
    Filed: June 27, 2012
    Publication date: January 3, 2013
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Hideki YAGI
  • Publication number: 20120308173
    Abstract: A method for manufacturing a semiconductor optical modulator includes forming a p-type semiconductor layer on a main surface of a p-type semiconductor substrate; forming a pair of stripe-shaped masks on the p-type semiconductor layer, the stripe-shaped masks extending in a first direction along the main surface of the p-type semiconductor substrate and being spaced apart from each other; simultaneously forming a hole and a pair of stripe structures extending in the first direction by etching the p-type semiconductor layer through the stripe-shaped masks, the pair of stripe structures defining the hole; after removing the stripe-shaped masks, forming a buried layer in the hole; forming a core layer on the buried layer and the stripe structures; and forming an upper cladding layer on the core layer. The buried layer is made of a semiconductor material with a lower optical absorption loss than that of the p-type semiconductor layer.
    Type: Application
    Filed: May 23, 2012
    Publication date: December 6, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Hideki YAGI
  • Publication number: 20120270347
    Abstract: A method of manufacturing a ridge-type semiconductor laser includes the steps of forming a stacked semiconductor layer including an active layer and an etch stop layer on first and second surfaces of a substrate, etching the stacked semiconductor layer on the second surface, forming a semiconductor portion on the second surface, forming a ridge waveguide portion by etching the stacked semiconductor layer on the first surface to a first depth, forming semiconductor diffraction grating portions by etching the semiconductor portion to a second depth, and forming a diffraction grating section by providing resin diffraction grating portions between the semiconductor diffraction grating portions. The etching of the stacked semiconductor layer on the first surface and the etching of the semiconductor portion are performed simultaneously by using first and second mask portions.
    Type: Application
    Filed: April 11, 2012
    Publication date: October 25, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Hideki YAGI
  • Patent number: 8218591
    Abstract: An LD with an improved heat dissipating function in the edge regions is disclosed. The LD provides the core region including the active layer and extending whole of the substrate, and the ridge waveguide structure on the core region that extends in a direction along which the light generated in the active layer is guided. The ridge waveguide structure is buried by a thick resin layer in both sides thereof, but the resin layer is removed in the edge regions close to respective facets of the LD.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: July 10, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yutaka Onishi, Hideki Yagi
  • Publication number: 20120094415
    Abstract: A method for producing a semiconductor optical device includes the steps of forming a semiconductor region including a ridge structure on a substrate; forming an insulating film on the semiconductor region; forming a non-photosensitive resin region on the insulating film, forming a first mask that defines a scribe area; forming the scribe area by etching using the first mask; after removing the first mask, forming an insulating layer by etching the insulating film, forming an electrode on the ridge structure and the non-photosensitive resin region to produce a substrate product; forming a scribe line on a surface of the semiconductor region in the scribe area of the substrate product; and cutting the product along the scribe line to form a semiconductor laser bar.
    Type: Application
    Filed: October 7, 2011
    Publication date: April 19, 2012
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Hideki YAGI, Hiroyuki Yoshinaga
  • Patent number: 8124543
    Abstract: A method for manufacturing an LD is disclosed. The LD has a striped structure including an optical active region. The striped structure is buried with resin, typically benzo-cyclo-butene (BCB). The method to form an opening in the BCB layer has tri-steps etching of the RIE. First step etches the BCB layer partially by a mixed gas of CF4 and O2, where CF4 has a first partial pressure, second step etches the photo-resist patterned on the top of the BCB layer by a mixed gas of CF4 and O2, where CF4 in this step has the second partial pressure less than the first partial pressure, and third step etches the BCB left in the first step by mixed gas of CF4 and O2, where CF4 in this step has the third partial pressure greater than the second partial pressure.
    Type: Grant
    Filed: May 24, 2010
    Date of Patent: February 28, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideki Yagi, Kenji Koyama, Hiroyuki Yoshinaga, Kuniaki Ishihara
  • Publication number: 20110275375
    Abstract: A mobile station (UE) according to the present invention includes: a reception unit (11) configured to receive broadcast information in a second cell, after a handover from a first cell to the second cell in response to received handover information; and a control unit (12) configured to continue a communication performed in the second cell by using the broadcast information when the reception unit (11) succeeds in receiving the broadcast information, and to perform a re-establishment process when it is determined that the reception unit (11) has failed to receive the broadcast information.
    Type: Application
    Filed: November 6, 2009
    Publication date: November 10, 2011
    Applicants: PANASONIC MOBILE COMMUNICATIONS CO., LTD., NTT DOCOMO, INC.
    Inventors: Hiroaki Yamagishi, Hideki Yagi, Masaaki Suzuki
  • Publication number: 20110164642
    Abstract: An LD with an improved heat dissipating function in the edge regions is disclosed. The LD provides the core region including the active layer and extending whole of the substrate, and the ridge waveguide structure on the core region that extends in a direction along which the light generated in the active layer is guided. The ridge waveguide structure is buried by a thick resin layer in both sides thereof, but the resin layer is removed in the edge regions close to respective facets of the LD.
    Type: Application
    Filed: December 17, 2010
    Publication date: July 7, 2011
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Yutaka ONISHI, Hideki Yagi
  • Patent number: 7957446
    Abstract: A semiconductor laser includes a first optical confinement layer, a plurality of first quantum wires and buried semiconductor regions disposed on a first area, a plurality of second quantum wires and buried semiconductor regions disposed on a second area, an active layer disposed on a third area, and a second optical confinement layer. The plurality of first quantum wires and the buried semiconductor regions constitute a first distributed Bragg reflector, and the plurality of second quantum wires and the buried semiconductor regions constitute a second distributed Bragg reflector. The third area is disposed between the first area and the second area. The buried semiconductor regions have a refractive index different from the average refractive index of the first quantum wires and the average refractive index of the second quantum wires. These distributed Bragg reflectors form a DBR laser having a cavity length defined by the length of the active layer.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: June 7, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Hideki Yagi
  • Patent number: 7947520
    Abstract: In the method of making a semiconductor laser, a semiconductor region is grown on an active layer, and a part of the semiconductor region is etched to form a ridge structure. An insulating film is formed over the ridge structure, and a resin layer of photosensitive material is formed to bury the ridge structure. A cured resin portion and an uncured resin portion are formed in the resin layer by performing lithographic exposure of the resin layer, and the uncured resin portion is on the top of the ridge structure. The uncured resin portion is removed to form a dent which is provided on the top of the ridge structure. An overall surface of the cured resin portion and dent is etched to form an etched resin layer. An opening is formed in the etched resin layer by thinning the cured resin portion, and a part of the insulating film is exposed in the opening of the etched resin layer. The part of the insulating film is etched using the etched resin layer as a mask to form an opening in the insulating film.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: May 24, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hideki Yagi, Toshio Nomaguchi, Kenji Hiratsuka
  • Publication number: 20100303115
    Abstract: A method for manufacturing an LD is disclosed. The LD has a striped structure including an optical active region. The striped structure is buried with resin, typically benzo-cyclo-butene (BCB). The method to form an opening in the BCB layer has tri-steps etching of the RIE. First step etches the BCB layer partially by a mixed gas of CF4 and O2, where CF4 has a first partial pressure, second step etches the photo-resist patterned on the top of the BCB layer by a mixed gas of CF4 and O2, where CF4 in this step has the second partial pressure less than the first partial pressure, and third step etches the BCB left in the first step by mixed gas of CF4 and O2, where CF4 in this step has the third partial pressure greater than the second partial pressure.
    Type: Application
    Filed: May 24, 2010
    Publication date: December 2, 2010
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Hideki Yagi, Kenji Koyama, Hiroyuki Yoshinaga, Kuniaki Ishihara
  • Patent number: 7736926
    Abstract: The invention provides a light-emitting device, where the active region thereof may be escaped from being damaged by the plasma process. The device is first formed with a semiconductor layer on the semiconductor substrate, next provided with an etching mask. Using the mask, the semiconductor layer on the substrate is dry-etched to form a periodic structure with grooves and mesas. The active regions are buried within the grooves by the OMVPE method.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: June 15, 2010
    Assignee: Sumitomo Electric Industries Ltd.
    Inventor: Hideki Yagi
  • Publication number: 20100034229
    Abstract: A semiconductor laser includes a first optical confinement layer, a plurality of first quantum wires and buried semiconductor regions disposed on a first area, a plurality of second quantum wires and buried semiconductor regions disposed on a second area, an active layer disposed on a third area, and a second optical confinement layer. The plurality of first quantum wires and the buried semiconductor regions constitute a first distributed Bragg reflector, and the plurality of second quantum wires and the buried semiconductor regions constitute a second distributed Bragg reflector. The third area is disposed between the first area and the second area. The buried semiconductor regions have a refractive index different from the average refractive index of the first quantum wires and the average refractive index of the second quantum wires. These distributed Bragg reflectors form a DBR laser having a cavity length defined by the length of the active layer.
    Type: Application
    Filed: May 12, 2009
    Publication date: February 11, 2010
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventor: Hideki YAGI
  • Publication number: 20090308937
    Abstract: An IC card includes: a rectifying circuit; a register section in which a plurality of setpoints related to the output voltage of the rectifying circuit are set; a voltage level detecting circuit configured to detect the output voltage level of the rectifying circuit on the basis of the setpoints set in the register section; a plurality of transistors for load modulation to be made valid or invalid according to the output voltage level detected by the voltage level detecting circuit; and a control section configured to generate transmission data according to reception data received by a receiving section and supply the transmission data to the plurality of transistors for load modulation.
    Type: Application
    Filed: June 8, 2009
    Publication date: December 17, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideki Yagi, Akira Mito