Patents by Inventor Toshimasa Kobayashi

Toshimasa Kobayashi 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: 20050227458
    Abstract: When a semiconductor light emitting device or a semiconductor device is produced using a nitride type III-V group compound semiconductor substrate on which a plurality of second regions made of a crystal having a second average dislocation density are regularly arranged in a first region made of a crystal having a first average dislocation density so as to produce the structured substrate, the second average dislocation density being greater than the first average dislocation density, a light emitting region of the semiconductor light emitting device or an active region of the semiconductor device is formed in such a manner that it does not pass through any one of the second regions.
    Type: Application
    Filed: March 30, 2004
    Publication date: October 13, 2005
    Inventors: Toshimasa Kobayashi, Kensaku Motoki
  • Publication number: 20050184302
    Abstract: Provided is a nitride semiconductor device with high reliability and high flexibility in design and manufacture of the device. The nitride semiconductor device comprises a seed crystal portion (11) formed on a sapphire substrate (10) and having a mask (12) on one side surface thereof, and a GaN layer (15) grown on the sapphire substrate (10) and the seed crystal portion (11) through epitaxial lateral overgrowth. The GaN layer (15) is grown only from an exposed side surface of the seed crystal portion (11) which is not covered with the mask (12), so the lateral growth of the GaN layer (15) is asymmetrically carried out. Thereby, a meeting portion (32) is formed in the vicinity of a boundary between the seed crystal portion (11) and the mask (12) in a thickness direction of the GaN layer (15).
    Type: Application
    Filed: April 22, 2005
    Publication date: August 25, 2005
    Inventors: Toshimasa Kobayashi, Katsunori Yanashima, Takashi Yamaguchi, Hiroshi Nakajima
  • Patent number: 6921673
    Abstract: Provided is a nitride semiconductor device with high reliability and high flexibility in design and manufacture of the device. The nitride semiconductor device comprises a seed crystal portion (11) formed on a sapphire substrate (10) and having a mask (12) on one side surface thereof, and a GaN layer (15) grown on the sapphire substrate (10) and the seed crystal portion (11) through epitaxial lateral overgrowth. The GaN layer (15) is grown only from an exposed side surface of the seed crystal portion (11) which is not covered with the mask (12), so the lateral growth of the GaN layer (15) is asymmetrically carried out. Thereby, a meeting portion (32) is formed in the vicinity of a boundary between the seed crystal portion (11) and the mask (12) in a thickness direction of the GaN layer (15).
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: July 26, 2005
    Assignee: Sony Corporation
    Inventors: Toshimasa Kobayashi, Katsunori Yanashima, Takashi Yamaguchi, Hiroshi Nakajima
  • Patent number: 6896143
    Abstract: An electrolytic machining method for electrolytically machining a workpiece is provided. The method uses a masking member having through-hole patterns that correspond to the shapes of concave parts to be formed in the workpiece. The masking member is brought in contact with a machining surface of the workpiece. An electrolytic solution is supplied and allowed to flow in the gap between the masking member and an electrode tool. The electrolytic solution is allowed to enter into and flow within the through-hole patterns of the masking member in order to electrolytically machine surfaces of the workpiece only in the through-hole patterns.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: May 24, 2005
    Assignee: Sankyo Seiki Mfg. Co., Ltd.
    Inventors: Motonori Usui, Toshimasa Kobayashi
  • Patent number: 6838703
    Abstract: The nitride-based semiconductor laser device 10 has a stacked structure comprising a first contacting layer 14, a first cladding layer 16, an active layer 20, a second cladding layer 24, a second contacting layer 26 and a second electrode 30 which are consecutively stacked, the second cladding layer 24 comprises a lower layer 24A and an upper layer 24B, the first cladding layer 14, the active layer 20 and the lower layer 24A of the second cladding layer have a mesa structure, the upper layer 24B of the second cladding layer and the second contacting layer 26 have a ridge structure, an insulating layer 40 covering at least part of each of both side surfaces of the upper layer 24B of the second cladding layer is formed on the portions of the lower layer 24A of the second cladding layer which portions correspond to the top surface of the mesa structure, and further, a metal layer 42 having substantially the same width as the mesa structure is formed on the top surface of the insulating layer 40 and the top surfa
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: January 4, 2005
    Assignee: Sony Corporation
    Inventors: Takashi Yamaguchi, Takashi Kobayashi, Toshimasa Kobayashi, Satoru Kijima, Satoshi Tomioka, Shinichi Ansai, Tsuyoshi Tojo
  • Patent number: 6784010
    Abstract: The nitride-based semiconductor laser device 10 has a stacked structure comprising a first contacting layer 14, a first cladding layer 16, an active layer 20, a second cladding layer 24, a second contacting layer 26 and a second electrode 30 which are consecutively stacked, the second cladding layer 24 comprises a lower layer 24A and an upper layer 24B, the first cladding layer 14, the active layer 20 and the lower layer 24A of the second cladding layer have a mesa structure, the upper layer 24B of the second cladding layer and the second contacting layer 26 have a ridge structure, an insulating layer 40 covering at least part of each of both side surfaces of the upper layer 24B of the second cladding layer is formed on the portions of the lower layer 24A of the second cladding layer which portions correspond to the top surface of the mesa structure, and further, a metal layer 42 having substantially the same width as the mesa structure is formed on the top surface of the insulating layer 40 and the top surfa
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: August 31, 2004
    Assignee: Sony Corporation
    Inventors: Takashi Yamaguchi, Takashi Kobayashi, Toshimasa Kobayashi, Satoru Kijima, Satoshi Tomioka, Shinichi Ansai, Tsuyoshi Tojo
  • Publication number: 20040159848
    Abstract: The nitride-based semiconductor laser device 10 has a stacked structure comprising a first contacting layer 14, a first cladding layer 16, an active layer 20, a second cladding layer 24, a second contacting layer 26 and a second electrode 30 which are consecutively stacked, the second cladding layer 24 comprises a lower layer 24A and an upper layer 24B, the first cladding layer 14, the active layer 20 and the lower layer 24A of the second cladding layer have a mesa structure, the upper layer 24B of the second cladding layer and the second contacting layer 26 have a ridge structure, an insulating layer 40 covering at least part of each of both side surfaces of the upper layer 24B of the second cladding layer is formed on the portions of the lower layer 24A of the second cladding layer which portions correspond to the top surface of the mesa structure, and further, a metal layer 42 having substantially the same width as the mesa structure is formed on the top surface of the insulating layer 40 and the top surfa
    Type: Application
    Filed: February 13, 2004
    Publication date: August 19, 2004
    Applicant: Sony Corporation
    Inventors: Takashi Yamaguchi, Takashi Kobayashi, Toshimasa Kobayashi, Satoru Kijima, Satoshi Tomioka, Shinichi Ansai, Tsuyoshi Tojo
  • Publication number: 20030217931
    Abstract: An electrolytic machining method includes electrolytically machining a workpiece that is positioned opposite to an electrode tool while filling an electrolytic solution between the workpiece and the electrode tool and applying a current across the workpiece and the electrode tool. The electrolytic machining is performed by having at least a part of opposing sections of the workpiece and the electrode tool immersed in the electrolytic solution reserved in a machining and storing section, while the machining surface of the workpiece is positioned at a depth of about 5 mm to about 35 mm from the surface of the electrolytic solution reserved in the machining and storing section, and by supplying the electrolytic solution to be filled in a gap at the opposing sections between the workpiece and the electrode tool.
    Type: Application
    Filed: March 4, 2003
    Publication date: November 27, 2003
    Applicant: SANKYO SEIKI MFG. CO., LTD.
    Inventors: Motonori Usui, Toshimasa Kobayashi
  • Publication number: 20030207480
    Abstract: A method of manufacturing a semiconductor device capable of improving adhesibility between a semiconductor layer and an electrode, while reducing contact resistance therebetween. A resist film is formed over the entire surface of an insulating layer formed by deposition or others. Then, in the resist film, provided is an opening corresponding to the p-side electrode pattern. Meanwhile, the residue of resist may attach to the opening, but is removed through light ashing treatments using oxygen, while a p-side contact layer is protected by the insulating layer. After that, with the resist film used as a mask, an opening in the insulating layer and a p-side electrode are formed by self-aligning. Damage to the surface of the p-side contact layer can be effectively suppressed. The p-side electrode can be formed on the clean surface of the p-side contact layer.
    Type: Application
    Filed: April 24, 2003
    Publication date: November 6, 2003
    Inventors: Toshimasa Kobayashi, Kaori Naganuma
  • Patent number: 6620641
    Abstract: A GaN compound semiconductor laser includes an AlGaN buried layer which buries opposite sides of a ridge stripe portion formed on a p-type AlGaN cladding layer. The AlGaN buried layer is made by first patterning an upper part of the p-type AlGaN cladding layer and a p-type GaN contact layer into a ridge stripe configuration by using a SiO2 film as an etching mask, then growing the AlGaN buried layer non-selectively on the entire substrate surface to bury both sides of the ridge stripe portion under the existence of the SiO2 film on the ridge stripe portion, and thereafter selectively removing the AlGaN buried layer from above the ridge stripe portion by etching using the SiO2 film as an etching stop layer. Thus, the GaN compound semiconductor laser is stabilized in the transverse mode, intensified in output power, and improved in lifetime.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: September 16, 2003
    Assignee: Sony Corporation
    Inventors: Takashi Yamaguchi, Toshimasa Kobayashi, Satoru Kijima, Takashi Kobayashi, Tsunenori Asatsuma, Takeharu Asano, Tomonori Hino
  • Publication number: 20030138981
    Abstract: The nitride-based semiconductor laser device 10 has a stacked structure comprising a first contacting layer 14, a first cladding layer 16, an active layer 20, a second cladding layer 24, a second contacting layer 26 and a second electrode 30 which are consecutively stacked, the second cladding layer 24 comprises a lower layer 24A and an upper layer 24B, the first cladding layer 14, the active layer 20 and the lower layer 24A of the second cladding layer have a mesa structure, the upper layer 24B of the second cladding layer and the second contacting layer 26 have a ridge structure, an insulating layer 40 covering at least part of each of both side surfaces of the upper layer 24B of the second cladding layer is formed on the portions of the lower layer 24A of the second cladding layer which portions correspond to the top surface of the mesa structure, and further, a metal layer 42 having substantially the same width as the mesa structure is formed on the top surface of the insulating layer 40 and the top surfa
    Type: Application
    Filed: November 6, 2002
    Publication date: July 24, 2003
    Inventors: Takashi Yamaguchi, Takashi Kobayashi, Toshimasa Kobayashi, Satoru Kijima, Satoshi Tomioka, Shinichi Ansai, Tsuyoshi Tojo
  • Publication number: 20030139037
    Abstract: Provided is a nitride semiconductor device with high reliability and high flexibility in design and manufacture of the device. The nitride semiconductor device comprises a seed crystal portion (11) formed on a sapphire substrate (10) and having a mask (12) on one side surface thereof, and a GaN layer (15) grown on the sapphire substrate (10) and the seed crystal portion (11) through epitaxial lateral overgrowth. The GaN layer (15) is grown only from an exposed side surface of the seed crystal portion (11) which is not covered with the mask (12), so the lateral growth of the GaN layer (15) is asymmetrically carried out. Thereby, a meeting portion (32) is formed in the vicinity of a boundary between the seed crystal portion (11) and the mask (12) in a thickness direction of the GaN layer (15).
    Type: Application
    Filed: November 19, 2002
    Publication date: July 24, 2003
    Inventors: Toshimasa Kobayashi, Katsunori Yanashima, Takashi Yamaguchi, Hiroshi Nakajima
  • Publication number: 20030019754
    Abstract: An electrolytic machining method for electrolytically machining a workpiece is provided. The method uses a masking member having through-hole patterns that correspond to the shapes of concave parts to be formed in the workpiece. The masking member is brought in contact with a machining surface of the workpiece. An electrolytic solution is supplied and allowed to flow in the gap between the masking member and an electrode tool. The electrolytic solution is allowed to enter into and flow within the through-hole patterns of the masking member in order to electrolytically machine surfaces of the workpiece only in the through-hole patterns.
    Type: Application
    Filed: July 18, 2002
    Publication date: January 30, 2003
    Inventors: Motonori Usui, Toshimasa Kobayashi
  • Patent number: 6482666
    Abstract: It is intended to provide a semiconductor device, its manufacturing method and substrate for manufacturing the semiconductor device which ensures that good cleavable surfaces be made stably in a semiconductor layer under precise control upon making edges of cleaves surfaces in the semiconductor layer stacked on a substrate even when the substrate is non-cleavable, difficult to cleave or different in cleavable orientation from the semiconductor layer. A semiconductor layer 2 made of III-V compound semiconductors is stacked to form a laser structure on a sapphire substrate 1.
    Type: Grant
    Filed: November 14, 2000
    Date of Patent: November 19, 2002
    Assignee: Sony Corporation
    Inventors: Toshimasa Kobayashi, Tsuyoshi Tojo
  • Publication number: 20020153528
    Abstract: A GaN compound semiconductor laser includes an AlGaN buried layer which buries opposite sides of a ridge stripe portion formed on a p-type AlGaN cladding layer. The AlGaN buried layer is made by first patterning an upper part of the p-type AlGaN cladding layer and a p-type GaN contact layer into a ridge stripe configuration by using a SiO2 film as an etching mask, then growing the AlGaN buried layer non-selectively on the entire substrate surface to bury both sides of the ridge stripe portion under the existence of the SiO2 film on the ridge stripe portion, and thereafter selectively removing the AlGaN buried layer from above the ridge stripe portion by etching using the SiO2 film as an etching stop layer. Thus, the GaN compound semiconductor laser is stabilized in the transverse mode, intensified in output power, and improved in lifetime.
    Type: Application
    Filed: June 17, 2002
    Publication date: October 24, 2002
    Inventors: Takashi Yamaguchi, Toshimasa Kobayashi, Satoru Kijima, Takashi Kobayashi, Tsunenori Asatsuma, Takeharu Asano, Tomonori Hino
  • Patent number: 6455342
    Abstract: It is intended to provide a semiconductor device, its manufacturing method and substrate for manufacturing the semiconductor device which ensures that good cleavable surfaces be made stably in a semiconductor layer under precise control upon making edges of cleaves surfaces in the semiconductor layer stacked on a substrate even when the substrate is non-cleavable, difficult to cleave or different in cleavable orientation from the semiconductor layer. A semiconductor layer 2 made of III-V compound semiconductors is stacked to form a laser structure on a sapphire substrate 1.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: September 24, 2002
    Assignee: Sony Corporation
    Inventors: Toshimasa Kobayashi, Tsuyoshi Tojo
  • Publication number: 20020060828
    Abstract: An air dynamic pressure bearing includes a shaft element, a bearing element relatively rotatably supporting the shaft element, and dynamic pressure generation grooves for generating a dynamic pressure by air formed between opposing surfaces of the shaft element and the bearing element. The bearing element is formed from a sintered alloy, and a solid lubricant material is disposed on the opposing surface of at least one of the shaft element and the bearing element.
    Type: Application
    Filed: October 3, 2001
    Publication date: May 23, 2002
    Inventors: Yutaka Ishizuka, Hisaya Nakagawa, Michiaki Takizawa, Takafumi Kuwazawa, Toshimasa Kobayashi, Akitoshi Iizawa, Masao Takemura
  • Patent number: 6281032
    Abstract: In a semiconductor device manufacturing method capable of manufacturing semiconductor lasers, light emitting diodes or electron transport devices using nitride III-V compound semiconductors with a high productivity, a GaN semiconductor laser wafer is prepared in which a plurality of semiconductor lasers are formed on an AlGaInN semiconductor layer on a c-face sapphire substrate and separated from each other by grooves deep enough to reach the c-face sapphire substrate, and a p-side electrode and an n-side electrode are formed in each semiconductor laser. The GaN semiconductor laser wafer is bonded to a photo-diode built-in Si wafer having formed a photo diode for monitoring light outputs and solder electrodes in each pellet by positioning the p-side electrode and the n-side electrode in alignment with the solder electrodes, respectively.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: August 28, 2001
    Assignee: Sony Corporation
    Inventors: Osamu Matsuda, Toshimasa Kobayashi, Norikazu Nakayama, Hiroji Kawai
  • Patent number: 6278173
    Abstract: It is intended to provide a semiconductor device, its manufacturing method and substrate for manufacturing the semiconductor device which ensures that good cleavable surfaces be made stably in a semiconductor layer under precise control upon making edges of cleaves surfaces in the semiconductor layer stacked on a substrate even when the substrate is non-cleavable, difficult to cleave or different in cleavable orientation from the semiconductor layer. A semiconductor layer 2 made of III-V compound semiconductors is stacked to form a laser structure on a sapphire substrate 1.
    Type: Grant
    Filed: March 1, 1999
    Date of Patent: August 21, 2001
    Assignee: Sony Corporation
    Inventors: Toshimasa Kobayashi, Tsuyoshi Tojo
  • Publication number: 20010013608
    Abstract: It is intended to provide a semiconductor device, its manufacturing method and substrate for manufacturing the semiconductor device which ensures that good cleavable surfaces be made stably in a semiconductor layer under precise control upon making edges of cleaves surfaces in the semiconductor layer stacked on a substrate even when the substrate is non-cleavable, difficult to cleave or different in cleavable orientation from the semiconductor layer. A semiconductor layer 2 made of III-V compound semiconductors is stacked to form a laser structure on a sapphire substrate 1.
    Type: Application
    Filed: April 23, 2001
    Publication date: August 16, 2001
    Inventors: Toshimasa Kobayashi, Tsuyoshi Tojo