Patents by Inventor Hisashi Nakayama
Hisashi Nakayama 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).
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Patent number: 7834366Abstract: A semiconductor device has a substrate, a first Group III nitride semiconductor layer formed on the substrate, a first oxide layer formed in proximity to the upper portions of defects present in the first Group III nitride semiconductor layer, and a second Group III nitride semiconductor layer including a positive layer and formed over each of the first Group III nitride semiconductor layer and the first oxide layer.Type: GrantFiled: July 24, 2006Date of Patent: November 16, 2010Assignee: Panasonic CorporationInventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri
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Patent number: 7795630Abstract: A semiconductor device, which includes an active layer made of a first semiconductor layer formed on a substrate, is designed so that a first oxidized area made of an oxide layer is formed on the active layer. The first oxidized area further aids in reducing a reactive current so that it becomes possible to achieve a semiconductor device having superior device characteristics.Type: GrantFiled: August 6, 2004Date of Patent: September 14, 2010Assignee: Panasonic CorporationInventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri, Toshiyuki Takizawa
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Patent number: 7713812Abstract: A substrate with a second semiconductor layer and a second mask film formed thereon is subjected to a heat treatment in an oxidizing atmosphere. Thus, second oxidized regions are formed through oxidization of the second semiconductor layer in regions of the second semiconductor layer that are not covered by the second mask film. At the same time, a second base layer is formed in each region that is interposed by the second oxidized regions. Then, the second mask film is removed, and a third semiconductor layer is selectively grown on the surface of the second base layer that is exposed between the second oxidized regions so as to cover the second oxidized regions, after which the first oxidized regions and the second oxidized regions covering the entire upper surface of the substrate are removed.Type: GrantFiled: January 12, 2006Date of Patent: May 11, 2010Assignee: Panasonic CorporationInventors: Tetsuzo Ueda, Hisashi Nakayama, Masaaki Yuri
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Patent number: 7711023Abstract: A semiconductor laser device has a multilayer structure including a first clad layer, an active layer, and a second clad layer stacked successively on a semiconductor substrate in order of increasing distance from the semiconductor substrate. At least one of the first clad layer and the second clad layer has a compressive distortion with respect to the semiconductor substrate. At least one of the first clad layer and the second clad layer includes a semiconductor layer having a tensile distortion with respect to the semiconductor substrate.Type: GrantFiled: March 26, 2007Date of Patent: May 4, 2010Assignee: Panasonic CorporationInventors: Yasuhiro Fujimoto, Toru Takayama, Satoshi Murasawa, Hisashi Nakayama, Isao Kidoguchi
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Patent number: 7704759Abstract: In a semiconductor laser device, a plurality of light-emitting elements emitting light with different wavelengths are integrated on a substrate. Each of the light-emitting elements includes, on the substrate, an active layer and cladding layers respectively provided on top and bottom of the active layer. One of the cladding layers provided on top of the active layer is an upper cladding layer having a mesa ridge portion. An etching stopper layer for forming the ridge portion is interposed between the ridge portion and the other portion of the upper cladding layer. The thickness of the etching stopper layer varies among the light-emitting elements.Type: GrantFiled: September 11, 2008Date of Patent: April 27, 2010Assignee: Panasonic CorporationInventors: Toru Takayama, Satoshi Murasawa, Yasuhiro Fujimoto, Hisashi Nakayama, Isao Kidoguchi
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Patent number: 7693202Abstract: In a monolithic dual wavelength laser device in which an infrared laser part 100 and a red laser part 130 are built on one n-type GaAs substrate 101, a p-type first cladding layer 105 of the infrared laser part 100 and a p-type first cladding layer 135 of the red laser part 130 are made of the same material and have different impurity concentrations.Type: GrantFiled: December 14, 2006Date of Patent: April 6, 2010Assignee: Panasonic CorporationInventors: Satoshi Murasawa, Toru Takayama, Hisashi Nakayama, Yasuhiro Fujimoto, Isao Kidoguchi
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Publication number: 20090086780Abstract: In a monolithic dual wavelength laser device in which an infrared laser part 100 and a red laser part 130 are built on one n-type GaAs substrate 101, a p-type first cladding layer 105 of the infrared laser part 100 and a p-type first cladding layer 135 of the red laser part 130 are made of the same material and have different impurity concentrations.Type: ApplicationFiled: December 14, 2006Publication date: April 2, 2009Applicant: SystraInventors: Satoshi Murasawa, Toru Takayama, Hisashi Nakayama, Yasuhiro Fujimoto, Isao Kidoguchi
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Publication number: 20090017570Abstract: In a semiconductor laser device, a plurality of light-emitting elements emitting light with different wavelengths are integrated on a substrate. Each of the light-emitting elements includes, on the substrate, an active layer and cladding layers respectively provided on top and bottom of the active layer. One of the cladding layers provided on top of the active layer is an upper cladding layer having a mesa ridge portion. An etching stopper layer for forming the ridge portion is interposed between the ridge portion and the other portion of the upper cladding layer. The thickness of the etching stopper layer varies among the light-emitting elements.Type: ApplicationFiled: September 11, 2008Publication date: January 15, 2009Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Toru TAKAYAMA, Satoshi Murasawa, Yasuhiro Fujimoto, Hisashi Nakayama, Isao Kidoguchi
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Patent number: 7433380Abstract: In a semiconductor laser device, a plurality of light-emitting elements emitting light with different wavelengths are integrated on a substrate. Each of the light-emitting elements includes, on the substrate, an active layer and cladding layers respectively provided on top and bottom of the active layer. One of the cladding layers provided on top of the active layer is an upper cladding layer having a mesa ridge portion. An etching stopper layer for forming the ridge portion is interposed between the ridge portion and the other portion of the upper cladding layer. The thickness of the etching stopper layer varies among the light-emitting elements.Type: GrantFiled: August 28, 2006Date of Patent: October 7, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toru Takayama, Satoshi Murasawa, Yasuhiro Fujimoto, Hisashi Nakayama, Isao Kidoguchi
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Publication number: 20070223550Abstract: A semiconductor laser device has a multilayer structure including a first clad layer, an active layer, and a second clad layer stacked successively on a semiconductor substrate in order of increasing distance from the semiconductor substrate. At least one of the first clad layer and the second clad layer has a compressive distortion with respect to the semiconductor substrate. At least one of the first clad layer and the second clad layer includes a semiconductor layer having a tensile distortion with respect to the semiconductor substrate.Type: ApplicationFiled: March 26, 2007Publication date: September 27, 2007Inventors: Yasuhiro Fujimoto, Toru Takayama, Satoshi Murasawa, Hisashi Nakayama, Isao Kidoguchi
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Publication number: 20070147457Abstract: In a semiconductor laser device, a plurality of light-emitting elements emitting light with different wavelengths are integrated on a substrate. Each of the light-emitting elements includes, on the substrate, an active layer and cladding layers respectively provided on top and bottom of the active layer. One of the cladding layers provided on top of the active layer is an upper cladding layer having a mesa ridge portion. An etching stopper layer for forming the ridge portion is interposed between the ridge portion and the other portion of the upper cladding layer. The thickness of the etching stopper layer varies among the light-emitting elements.Type: ApplicationFiled: August 28, 2006Publication date: June 28, 2007Inventors: Toru Takayama, Satoshi Murasawa, Yasuhiro Fujimoto, Hisashi Nakayama, Isao Kidoguchi
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Publication number: 20060255350Abstract: A semiconductor device has a substrate, a first Group III nitride semiconductor layer formed on the substrate, a first oxide layer formed in proximity to the upper portions of defects present in the first Group III nitride semiconductor layer, and a second Group III nitride semiconductor layer including a positive layer and formed over each of the first Group III nitride semiconductor layer and the first oxide layer.Type: ApplicationFiled: July 24, 2006Publication date: November 16, 2006Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri
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Patent number: 7091524Abstract: A semiconductor device has a substrate, a first Group III nitride semiconductor layer formed on the substrate, a first oxide layer formed in proximity to the upper portions of defects present in the first Group III nitride semiconductor layer, and a second Group III nitride semiconductor layer including a positive layer and formed over each of the first Group III nitride semiconductor layer and the first oxide layer.Type: GrantFiled: March 25, 2004Date of Patent: August 15, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri
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Publication number: 20060121695Abstract: A substrate with a second semiconductor layer and a second mask film formed thereon is subjected to a heat treatment in an oxidizing atmosphere. Thus, second oxidized regions are formed through oxidization of the second semiconductor layer in regions of the second semiconductor layer that are not covered by the second mask film. At the same time, a second base layer is formed in each region that is interposed by the second oxidized regions. Then, the second mask film is removed, and a third semiconductor layer is selectively grown on the surface of the second base layer that is exposed between the second oxidized regions so as to cover the second oxidized regions, after which the first oxidized regions and the second oxidized regions covering the entire upper surface of the substrate are removed.Type: ApplicationFiled: January 12, 2006Publication date: June 8, 2006Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Tetsuzo Ueda, Hisashi Nakayama, Masaaki Yuri
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Patent number: 7008839Abstract: A substrate with a second semiconductor layer and a second mask film formed thereon is subjected to a heat treatment in an oxidizing atmosphere. Thus, second oxidized regions are formed through oxidization of the second semiconductor layer in regions of the second semiconductor layer that are not covered by the second mask film. At the same time, a second base layer is formed in each region that is interposed by the second oxidized regions. Then, the second mask film is removed, and a third semiconductor layer is selectively grown on the surface of the second base layer that is exposed between the second oxidized regions so as to cover the second oxidized regions, after which the first oxidized regions and the second oxidized regions covering the entire upper surface of the substrate are removed.Type: GrantFiled: March 7, 2003Date of Patent: March 7, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tetsuzo Ueda, Hisashi Nakayama, Masaaki Yuri
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Publication number: 20050029531Abstract: A semiconductor device, which includes an active layer made of a first semiconductor layer formed on a substrate, is designed so that a first oxidized area made of an oxide layer is formed on the active layer.Type: ApplicationFiled: August 6, 2004Publication date: February 10, 2005Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri, Toshiyuki Takizawa
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Publication number: 20040188693Abstract: A semiconductor device has a substrate, a first Group III nitride semiconductor layer formed on the substrate, a first oxide layer formed in proximity to the upper portions of defects present in the first Group III nitride semiconductor layer, and a second Group III nitride semiconductor layer including a positive layer and formed over each of the first Group III nitride semiconductor layer and the first oxide layer.Type: ApplicationFiled: March 25, 2004Publication date: September 30, 2004Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri
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Patent number: 6636541Abstract: A semiconductor laser device includes a substrate, a p-type cladding layer and a n-type cladding layer provided on the substrate, and an active layer provided between the p-type cladding layer and the n-type cladding layer, having at least two barrier layers and at least two well layers, the barrier layers and the well layers being disposed alternately. Band offsets in a conduction band between the barrier layers and the well layers are provided so as to increase from the n-type cladding layer aide toward the p-type cladding layer side.Type: GrantFiled: March 2, 2000Date of Patent: October 21, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hisashi Nakayama, Masahiro Kito, Masato Ishino, Yasushi Matsui
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Publication number: 20030186475Abstract: A substrate with a second semiconductor layer and a second mask film formed thereon is subjected to a heat treatment in an oxidizing atmosphere. Thus, second oxidized regions are formed through oxidization of the second semiconductor layer in regions of the second semiconductor layer that are not covered by the second mask film. At the same time, a second base layer is formed in each region that is interposed by the second oxidized regions. Then, the second mask film is removed, and a third semiconductor layer is selectively grown on the surface of the second base layer that is exposed between the second oxidized regions so as to cover the second oxidized regions, after which the first oxidized regions and the second oxidized regions covering the entire upper surface of the substrate are removed.Type: ApplicationFiled: March 7, 2003Publication date: October 2, 2003Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Tetsuzo Ueda, Hisashi Nakayama, Masaaki Yuri