Patents by Inventor Yoshiki Miura

Yoshiki Miura 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: 20070215982
    Abstract: A method of forming an iron-doped gallium nitride for a semi-insulating GaN substrate is provided. A substrate 1, such as a sapphire substrate having the (0001) plane, is placed on a susceptor of a metalorganic hydrogen chloride vapor phase apparatus 11. Next, gaseous iron compound GFe from a source 13 for an iron compound, such as ferrocene, and hydrogen chloride gas G1HCl from a hydrogen chloride source 15 are caused to react with each other in a mixing container 16 to generate gas GFeComp of an iron-containing reaction product, such as iron chloride (FeCl2). In association with the generation, the iron-containing reaction product GFeComp, first substance gas GN containing elemental nitrogen from a nitrogen source 17, and second substance gas GGa containing elemental gallium are supplied to a reaction tube 21 to form iron-doped gallium nitride 23 on the substrate 1.
    Type: Application
    Filed: March 20, 2006
    Publication date: September 20, 2007
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Akinori Koukitu, Yoshinao Kumagai, Yoshiki Miura, Kikurou Takemoto, Fumitaka Sato
  • Patent number: 6294019
    Abstract: In the present method, a group III-V compound semiconductor wafer includes a substrate consisting of a group III-V compound whose outer peripheral edge portion is so chamfered that its section has an arcuate shape substantially with a radius R, and an epitaxial layer consisting of a group III-V compound layer formed on the substrate. A portion of the wafer is removed at the outer peripheral edge thereof, up to a distance L from the original peripheral edge, and the distance L satisfies the expression R≦L≦3L. thereby an abnormally grown part of the epitaxial layer is reliably removed.
    Type: Grant
    Filed: June 6, 2000
    Date of Patent: September 25, 2001
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshiki Miura, Toshiyuki Morimoto
  • Patent number: 6031252
    Abstract: An epitaxial wafer enabling epitaxial growth at a high temperature includes a compound semiconductor substrate containing As or P, and a covering layer including GaN; or InN; or AlN; or a nitride mixed-crystalline material containing Al, Ga, In and N. The covering layer covers at least a front surface and a back surface of the substrate. A method of preparing such an epitaxial wafer including steps of growing the covering layer at a growth temperature of at least 300.degree. C. and less than 800.degree. C. so as to cover at least the front and back surfaces of the substrate, and then annealing the substrate having the covering thereon layer at a temperature of at least 700.degree. C. and less than 1200.degree. C.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: February 29, 2000
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshiki Miura, Mitsuru Shimazu, Kensaku Motoki, Takuji Okahisa, Masato Matsushima, Hisashi Seki, Akinori Koukitu
  • Patent number: 5970314
    Abstract: A process for forming a high quality epitaxial compound semiconductor layer of indium gallium nitride In.sub.x Ga.sub.1-x N, (where 0<x<1) on a substrate. A first gas including indium trichloride (InCl.sub.3) and a second gas including ammonia (NH.sub.3) are introduced into a reaction chamber and heated at a first temperature. Indium nitride (InN) is grown epitaxially on the substrate by nitrogen (N.sub.2) carrier gas to form an InN buffer layer. Thereafter, a third gas including hydrogen chloride (H1) and gallium (Ga) is introduced with the first and second gases into a chamber heated at a second temperature higher than the first temperature and an epitaxial In.sub.x Ga.sub.1-x N layer is grown on the buffer layer by N.sub.2 gas. By using helium, instead of N.sub.2, as carrier gas, the In.sub.x Ga.sub.1-x N layer with more homogeneous quality is obtained. In addition, the InN buffer layer is allowed to be modified into a GaN buffer layer.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: October 19, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takuji Okahisa, Mitsuru Shimazu, Masato Matsushima, Yoshiki Miura, Kensaku Motoki, Hisashi Seki, Akinori Koukitu
  • Patent number: 5962875
    Abstract: A light emitting device having higher blue luminance is obtained. A gallium nitride compound layer is formed on a GaAs substrate, and thereafter the GaAs substrate is at least partially removed for forming the light emitting device. Due to the removal of the GaAs substrate, the quantity of light absorption is reduced as compared with the case of leaving the overall GaAs substrate. Thus, a light emitting device having high blue luminance is obtained.
    Type: Grant
    Filed: April 7, 1998
    Date of Patent: October 5, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kensaku Motoki, Mitsuru Shimazu, Yoshiki Miura
  • Patent number: 5864573
    Abstract: A compound semiconductor light emitting device having a long life and high performance and a method for industrially fabricating the same are provided. The compound semiconductor light emitting device includes a GaP substrate, a buffer layer consisting of InN which is formed on the substrate, a relaxation layer consisting of In.sub.x Ga.sub.1-x N which is formed on the buffer layer, and a luminescent layer consisting of In.sub.k Ga.sub.1-k N which is formed on the relaxation layer. In this description, k represents a constant value within the range of 0<k<1, and x (excluding 1 and k) decreases from 1 to k through the relaxation layer in the direction of thickness from the side adjacent the buffer layer toward the side adjacent the luminescent layer. In fabrication of the compound semiconductor light emitting device having the aforementioned structure, a buffer layer and an epitaxial layer are formed by the same organic metal chloride vapor phase epitaxy process.
    Type: Grant
    Filed: April 23, 1996
    Date of Patent: January 26, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshiki Miura, Hideki Matsubara, Hisashi Seki, Akinori Koukitu
  • Patent number: 5843590
    Abstract: A high performance epitaxial wafer which is useful, for example in a light emitting device is produced with a buffer layer. The epitaxial wafer has a substrate of a compound semiconductor selected from a group consisting of GaAs, GaP, InAs and InP. The buffer layer of GaN is grown on the substrate to a thickness within the range of 10 nm to 80 nm. An epitaxial layer of GaN is formed on the buffer layer. The buffer layer is grown at a first temperature by organic metal chloride vapor phase epitaxy, while the epitaxial layer is grown at a second temperature, which is higher than the first temperature, by the organic metal chloride vapor phase epitaxy.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: December 1, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshiki Miura, Keiichiro Fujita, Kikurou Takemoto, Masato Matsushima, Hideki Matsubara, Shigenori Takagishi, Hisashi Seki, Akinori Koukitu
  • Patent number: 5834325
    Abstract: A light emitting device having higher blue luminance is obtained. A gallium nitride compound layer is formed on a GaAs substrate, and thereafter the GaAs substrate is at least partially removed for forming the light emitting device. Due to the removal of the GaAs substrate, the quantity of light absorption is reduced as compared with the case of leaving the overall GaAs substrate. Thus, a light emitting device having high blue luminance is obtained.
    Type: Grant
    Filed: May 28, 1997
    Date of Patent: November 10, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kensaku Motoki, Mitsuru Shimazu, Yoshiki Miura
  • Patent number: 5756374
    Abstract: A compound semiconductor light emitting device of high performance and a method which can industrially prepare the same are provided. The compound semiconductor light emitting device includes a GaAs substrate, a buffer layer consisting of GaN, having a thickness of 10 nm to 80 nm, which is formed on the substrate, an epitaxial layer consisting of Al.sub.x Ga.sub.1-x N(0.ltoreq.x<1) which is formed on the buffer layer, an incommensurate plane which is located on the interface between the buffer layer and the epitaxial layer, a light emitting layer which is formed on the epitaxial layer, and a cladding layer which is formed on the light emitting layer. The buffer layer is formed by organic metal chloride vapor phase epitaxy at a first temperature, while the epitaxial layer is formed by organic metal chloride vapor phase epitaxy at a second temperature which is higher than the first temperature. The light emitting layer preferably consists of In.sub.y Ga.sub.1-y N (0<y<1) which is doped with Mg.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: May 26, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshiki Miura, Hideki Matsubara, Masato Matsushima, Hisashi Seki, Akinori Koukitu
  • Patent number: 5665986
    Abstract: A compound semiconductor light emitting device of high performance and a method which can industrially prepare the same are provided. The compound semiconductor light emitting device includes a GaAs substrate, a buffer layer consisting of GaN, having a thickness of 10 nm to 80 nm, which is formed on the substrate, an epitaxial layer consisting of Al.sub.x Ga.sub.1-x N (0.ltoreq.x<1) which is formed on the buffer layer, an incommensurate plane which is located on the interface between the buffer layer and the epitaxial layer, a light emiting layer which is formed on the epitaxial layer, and a cladding layer which is formed on the light emitting layer. The buffer layer is formed by organic metal chloride vapor phase epitaxy at a first temperature, while the epitaxial layer is formed by organic metal chloride vapor phase epitaxy at a second temperature which is higher than the first temperature. The light emitting layer preferably consists of In.sub.y Ga.sub.1-y N (0<y<1) which is doped with Mg.
    Type: Grant
    Filed: March 7, 1996
    Date of Patent: September 9, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Yoshiki Miura, Hideki Matsubara, Masato Matsushima, Hisashi Seki, Akinori Koukitu
  • Patent number: 5212394
    Abstract: A compound semiconductor epitaxial wafer has a heteroepitaxial crystal layer grown on a compound semiconductor crystal substrate which has a substantially circular configuration and is free of dislocation defects at least in a central area surrounded by a cut-off that prevents defects from propagating radially inwardly into said central area.
    Type: Grant
    Filed: August 19, 1992
    Date of Patent: May 18, 1993
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takashi Iwasaki, Naoyuki Yamabayashi, Yoshiki Miura