Patents by Inventor Toyoharu Oohata

Toyoharu Oohata 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: 6870125
    Abstract: Disclosed are a crystal layer separation method capable of separating a crystal layer formed on a substrate therefrom without occurrence of any crack, and a laser irradiation method used therefor, and a method of fabricating devices using the same. The crystal layer separation method includes the step of separating a crystal layer made from a GaN based compound formed on a sapphire substrate therefrom by irradiating the crystal layer with a laser beam from the back surface of the substrate, wherein the crystal layer is irradiated with the laser beam in a line-shape. In this method, an irradiation width of the laser beam is preferably equal to or less than a thickness of the crystal layer, and the laser beam preferably has a light intensity distribution smoothened in the width direction.
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: March 22, 2005
    Assignee: Sony Corporation
    Inventors: Masato Doi, Toshiaki Iwafuchi, Toyoharu Oohata
  • Patent number: 6870190
    Abstract: A display unit and semiconductor light emitting devices are provided. The display unit includes a number of the semiconductor light emitting devices arrayed on a base body, wherein each of the semiconductor light emitting devices is formed together with dummy devices for setting an emission wavelength of the semiconductor light emitting device, and the semiconductor light emitting device is formed by selective growth, and one conductive layer is formed in self-alignment on planes grown from tilt planes formed by selective growth. Such a display unit has a structure suitable for multi-colors without increasing the number of production steps.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: March 22, 2005
    Assignee: Sony Corporation
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Toyoharu Oohata, Masaru Minami
  • Publication number: 20050045894
    Abstract: Semiconductor light emitting devices and methods of producing same are provided. The semiconductor light emitting devices include a substrate that has a surface including a difference-in-height portion composed of, for example, a wurtzite compound. A crystal growth layer is formed in the substrate surface wherein at least a portion of which is oriented along an inclined plane with respect to a principal plane of the substrate. The semiconductor device includes a first conductive layer, an active layer and a second conductive layer formed on the crystal layer in a stacked arrangement and oriented along the inclined place.
    Type: Application
    Filed: October 8, 2004
    Publication date: March 3, 2005
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Toyoharu Oohata
  • Publication number: 20050042784
    Abstract: A device transfer method includes the steps of: covering a plurality of devices, which have been formed on a substrate, with a resin layer; forming electrodes in the resin layer in such a manner that the electrodes are connected to the devices; cutting the resin layer, to obtain resin buried devices each containing at least one of the devices; and peeling the resin buried devices from the substrate and transferring them to a device transfer body. This device transfer method is advantageous in easily, smoothly separating devices from each other, and facilitating handling of the devices in a transfer step and ensuring good electric connection between the devices and external wiring, even if the devices are fine devices.
    Type: Application
    Filed: September 23, 2004
    Publication date: February 24, 2005
    Inventors: Yoshiyuki Yanagisawa, Toyoharu Oohata, Toshiaki Iwafuchi
  • Publication number: 20040266043
    Abstract: An n-type GaN layer is grown onto a sapphire substrate and a hexagonal etching mask is formed onto the n-type GaN layer as provided. The n-type GaN layer is etched to a predetermined depth by using the etching mask by the RIE method. A hexagonal prism portion whose upper surface is a C plane is formed. After the etching mask was removed, an active layer and a p-type GaN layer are sequentially grown onto the whole surface of the substrate so as to cover the hexagonal prism portion, thereby forming a light emitting device structure. After that, a p-side electrode is formed onto the p-type GaN layer of the hexagonal prism portion and an n-side electrode is formed onto the n-type GaN layer.
    Type: Application
    Filed: May 4, 2004
    Publication date: December 30, 2004
    Inventors: Toyoharu Oohata, Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Jun Suzuki
  • Publication number: 20040259282
    Abstract: A semiconductor crystal layer formed by epitaxial growth on a seed crystal substrate is embedded in an insulating material in the condition where the seed crystal substrate is removed, electrodes are provided respectively on a first surface of the semiconductor crystal layer and a second surface of the semiconductor layer opposite to the first surface, and lead-out electrodes connected to the electrodes are led out to the same surface side of the insulating material. The semiconductor crystal layer functions as a semiconductor light-emitting device or a semiconductor electronic device. The insulating material is, for example, a resin.
    Type: Application
    Filed: July 20, 2004
    Publication date: December 23, 2004
    Applicant: Sony Corporation
    Inventor: Toyoharu Oohata
  • Patent number: 6830946
    Abstract: A device transfer method includes the steps of: covering a plurality of devices, which have been formed on a substrate, with a resin layer; forming electrodes in the resin layer in such a manner that the electrodes are connected to the devices; cutting the resin layer, to obtain resin buried devices each containing at least one of the devices; and peeling the resin buried devices from the substrate and transferring them to a device transfer body. This device transfer method is advantageous in easily, smoothly separating devices from each other, and facilitating handling of the devices in a transfer step and ensuring good electric connection between the devices and external wiring, even if the devices are fine devices.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: December 14, 2004
    Assignee: Sony Corporation
    Inventors: Yoshiyuki Yanagisawa, Toyoharu Oohata, Toshiaki Iwafuchi
  • Patent number: 6831300
    Abstract: In a semiconductor light emitting device configured to extract light through a substrate thereof, an electrode layer is formed on a p-type semiconductor layer (such as p-type GaN layer) formed on an active layer, and a nickel layer is formed as a contact metal layer between the electrode layer and the p-type semiconductor layer and adjusted in thickness not to exceed the intrusion length of light generated in the active layer. Since the nickel layer is sufficiently thin, reflection efficiency can be enhanced.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: December 14, 2004
    Assignee: Sony Corporation
    Inventors: Masato Doi, Hiroyuki Okuyama, Goshi Biwa, Toyoharu Oohata
  • Patent number: 6831937
    Abstract: A method of fabricating a semiconductor laser device includes the steps of forming semiconductor layers composed of a first conductive type cladding layer, an active layer, and a second conductive type cladding layer on a substrate, and peeling a device formation region of the semiconductor layers from the substrate and simultaneously forming a resonance mirror on an end portion of the device formation region by irradiating the device formation region with energy beams traveling from the back surface side of the substrate. With this configuration, it is possible to peel a device from a substrate and also form a flat resonance mirror with less damage of crystal by laser abrasion, and further to easily form a high quality resonance mirror without increasing the number of fabrication steps.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: December 14, 2004
    Assignee: Sony Corporation
    Inventors: Masato Doi, Toyoharu Oohata
  • Patent number: 6828591
    Abstract: Semiconductor light emitting devices and methods of producing same are provided. The semiconductor light emitting devices include a substrate that has a surface including a difference-in-height portion composed of, for example, a wurtzite compound. A crystal growth layer is formed in the substrate surface wherein at least a portion of which is oriented along an inclined plane with respect to a principal plane of the substrate. The semiconductor device includes a first conductive layer, an active layer and a second conductive layer formed on the crystal layer in a stacked arrangement and oriented along the inclined place.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: December 7, 2004
    Assignee: Sony Corporation
    Inventors: Hiroyuki Okuyama, Masato Doi, Goshi Biwa, Toyoharu Oohata
  • Publication number: 20040227152
    Abstract: Nitride semiconductor devices and methods of producing same are provided. The present invention includes forming a nitride semiconductor layer on a base body of the nitride semiconductor under selective and controlled crystal growth conditions. For example, the crystal growth rate, the supply of crystal growth source material and/or the crystal growth area can be varied over time, thus resulting in a nitride semiconductor device with enhanced properties.
    Type: Application
    Filed: June 15, 2004
    Publication date: November 18, 2004
    Inventors: Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Patent number: 6818465
    Abstract: Nitride semiconductor devices and methods of fabricating same are provided. The nitride semiconductor device includes a crystal layer grown into a three-dimensional shape having a side surface portion and an upper layer portion, wherein an electrode layer is formed on the upper layer portion via a high resistance region formed by an undoped gallium nitride layer or the like. Since the high resistance region is provided on the upper layer portion, a current flows so as to bypass the high resistance region of the upper layer portion, to form a current path extending mainly or substantially along the side surface portion while avoiding the upper layer portion, thereby suppressing the flow of a current in the upper layer portion poor in crystallinity.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: November 16, 2004
    Assignee: Sony Corporation
    Inventors: Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Patent number: 6818463
    Abstract: Nitride semiconductor devices and methods of producing same are provided. The present invention includes forming a nitride semiconductor layer on a base body of the nitride semiconductor under selective and controlled crystal growth conditions. For example, the crystal growth rate, the supply of crystal growth source material and/or the crystal growth area can be varied over time, thus resulting in a nitride semiconductor device with enhanced properties.
    Type: Grant
    Filed: April 18, 2002
    Date of Patent: November 16, 2004
    Assignee: Sony Corporation
    Inventors: Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Publication number: 20040164312
    Abstract: A first conductive type layer having a band gap energy smaller than that of an under growth layer formed on a substrate is formed by selective growth from an opening portion formed in the under growth layer, and an active layer and a second conductive type layer are stacked on the first conductive type layer, to form a stacked structure. When such a stacked structure for forming a semiconductor device is irradiated with laser beams having an energy value between the band gap energies of the under growth layer and the first conductive type layer, abrasion occurs at a first conductive type layer side interface between the under growth layer and the first conductive type layer, so that the stacked structure is peeled from the substrate and the under growth layer and simultaneously isolated from another stacked structure for forming another semiconductor device.
    Type: Application
    Filed: February 25, 2004
    Publication date: August 26, 2004
    Inventors: Goshi Biwa, Hiroyuki Okuyama, Masato Doi, Toyoharu Oohata
  • Patent number: 6773943
    Abstract: A display unit having a sufficient luminance and a method of fabricating the display unit are provided. The display unit includes micro-sized semiconductor light emitting devices fixedly arrayed on a plane of a base body of the display unit at intervals. Micro-sized GaN based semiconductor light emitting devices formed by selective growth are each buried in a first insulating layer made from an epoxy resin except an upper end portion and a lower end surface thereof, and electrodes of each of the light emitting devices are extracted. These light emitting devices are fixedly arrayed on the upper plane of the base body at intervals. A second insulating layer made from an epoxy resin is formed on the plane of the base body so as to cover the semiconductor light emitting devices each of which has been buried in the first insulating layer.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: August 10, 2004
    Assignee: Sony Corporation
    Inventors: Toyoharu Oohata, Hideharu Nakajima, Yoshiyuki Yanagisawa, Toshiaki Iwafuchi
  • Patent number: 6770960
    Abstract: A semiconductor crystal layer formed by epitaxial growth on a seed crystal substrate is embedded in an insulating material in the condition where the seed crystal substrate is removed, electrodes are provided respectively on a first surface of the semiconductor crystal layer and a second surface of the semiconductor layer opposite to the first surface, and lead-out electrodes connected to the electrodes are led out to the same surface side of the insulating material. The semiconductor crystal layer functions as a semiconductor light-emitting device or a semiconductor electronic device. The insulating material is, for example, a resin.
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: August 3, 2004
    Assignee: Sony Corporation
    Inventor: Toyoharu Oohata
  • Publication number: 20040137662
    Abstract: A device transfer method includes the steps of: covering a plurality of devices, which have been formed on a substrate, with a resin layer; forming electrodes in the resin layer in such a manner that the electrodes are connected to the devices; cutting the resin layer, to obtain resin buried devices each containing at least one of the devices; and peeling the resin buried devices from the substrate and transferring them to a device transfer body. This device transfer method is advantageous in easily, smoothly separating devices from each other, and facilitating handling of the devices in a transfer step and ensuring good electric connection between the devices and external wiring, even if the devices are fine devices.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 15, 2004
    Inventors: Yoshiyuki Yanagisawa, Toyoharu Oohata, Toshiaki Iwafuchi
  • Publication number: 20040115849
    Abstract: An image display unit and a method of producing the image display unit, wherein the image display unit includes an array of a plurality of light emitting devices for displaying an image, and wherein the method of producing the image display unit employs, for example, a space expanding transfer, whereby a first transfer step includes transferring the devices arrayed on a first substrate to a temporary holding member such that the devices are spaced from each other with a pitch larger than a pitch of the devices arrayed on the first substrate, a second holding step includes holding the devices on the temporary holding member, and a third transfer step includes transferring the devices held on the temporary holding member onto a second board such that the devices are spaced from each other with a pitch larger than the pitch of the devices held on the temporary holding member.
    Type: Application
    Filed: April 30, 2003
    Publication date: June 17, 2004
    Inventors: Toshiaki Iwafuchi, Toyoharu Oohata, Masato Doi
  • Publication number: 20040108819
    Abstract: The invention provides an electrochromic display unit with high-quality display. The display unit comprises a transparent electrode (1), a display layer (2) which is formed on the transparent electrode (1) and which changes a color according to the amount of accumulated electrical charges, and an ion conductive layer (3) formed on the display layer (2). A plurality of picture electrodes (4) are formed on the ion conductive layer (3) on the side opposite to the display layer (2). The picture electrodes (4) are driven independently by, for example, a corresponding thin film transistors (6). In driving, by applying a drive current having given amount of electrical charges and then applying a certain amount of an inverted current, a certain amount of coloration is deducted, and extra coloration of the display layer (2) is eliminated.
    Type: Application
    Filed: September 26, 2003
    Publication date: June 10, 2004
    Inventors: Michio Arai, Eriko Matsui, Kenji Shinozaki, Toyoharu Oohata
  • Patent number: 6734030
    Abstract: Semiconductor light emitting devices and a method of fabricating the semiconductor light emitting devices are provided. The semiconductor light emitting device includes a growth substrate, a first growth layer formed on the growth substrate, a growth obstruction film formed on the first growth layer, and a second growth layer formed by selective growth from an opening portion formed in the growth obstruction film, wherein device isolation trenches for isolating devices from each other are formed in the first growth layer formed on the growth substrate, and the second growth layer is formed by selective growth after formation of the device isolation trenches.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: May 11, 2004
    Assignee: Sony Corporation
    Inventors: Masato Doi, Hiroyuki Okuyama, Goshi Biwa, Toyoharu Oohata