Patents by Inventor Yasuhito Uchiyama
Yasuhito Uchiyama 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: 8395106Abstract: An optical semiconductor device includes a lower electrode layer formed over a semiconductor substrate, an infrared absorption layer formed over the lower electrode layer 26, and an upper electrode layer 38 formed over the infrared absorption layer 36. The infrared absorption layer includes a quantum dot having dimensions different among directions stacked, and is sensitive to infrared radiation of wavelengths different corresponding to polarization directions.Type: GrantFiled: August 4, 2009Date of Patent: March 12, 2013Assignees: Technical Research & Development Institute Ministry of Defense of Japan, Fujitsu LimitedInventors: Minoru Doshida, Mitsuhiro Nagashima, Michiya Kibe, Hiroyasu Yamashita, Hironori Nishino, Yusuke Matsukura, Yasuhito Uchiyama
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Patent number: 8373155Abstract: An infrared photodetector including a layer structure of an intermediate layer, and a quantum dot layer having a narrower band gap than the intermediate layer and including a plurality of quantum dots alternately stacked, and detecting photocurrent generated when infrared radiation is applied to the layer structure to thereby detect the infrared radiation, the infrared photodetector further including a first barrier layer provided on one side of the quantum dot layer and having a larger band gap than the intermediate layer; and a second barrier layer provided on the other side of the quantum dot layer and having a larger band gap than the intermediate layer.Type: GrantFiled: August 3, 2009Date of Patent: February 12, 2013Assignees: Technical Research & Development Institute Ministry of Defense of Japan, Fujitsu LimitedInventors: Toshihiro Okamura, Mitsuhiro Nagashima, Michiya Kibe, Hironori Nishino, Yasuhito Uchiyama, Yusuke Matsukura
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Patent number: 8076740Abstract: A photo detector is provided with a plurality of quantum dot layers and first conductive type contact layers provided at both sides of the plurality of quantum dot layers so as to sandwich them; a second conductive type impurity is doped in a first semiconductor layer formed between one first conductive type contact layer and a first quantum dot layer which is closest to the one first conductive type contact layer so that it results in a barrier against a carrier positioned at the one first conductive contact layer.Type: GrantFiled: June 14, 2006Date of Patent: December 13, 2011Assignee: Fujitsu LimitedInventors: Yasuhito Uchiyama, Hironori Nishino
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Publication number: 20100032552Abstract: An optical semiconductor device includes a lower electrode layer formed over a semiconductor substrate, an infrared absorption layer formed over the lower electrode layer 26, and an upper electrode layer 38 formed over the infrared absorption layer 36. The infrared absorption layer includes a quantum dot having dimensions different among directions stacked, and is sensitive to infrared radiation of wavelengths different corresponding to polarization directions.Type: ApplicationFiled: August 4, 2009Publication date: February 11, 2010Applicants: TECHNICAL RESEARCH & DEVELOPMENT INSTITUTE MINISTRY OF DEFENSE OF JAPAN, FUJITSU LIMITEDInventors: Minoru Doshida, Mitsuhiro Nagashima, Michiya Kibe, Hiroyasu Yamashita, Hironori Nishino, Yusuke Matsukura, Yasuhito Uchiyama
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Publication number: 20100032652Abstract: An infrared photodetector including a layer structure of an intermediate layer, and a quantum dot layer having a narrower band gap than the intermediate layer and including a plurality of quantum dots alternately stacked, and detecting photocurrent generated when infrared radiation is applied to the layer structure to thereby detect the infrared radiation, the infrared photodetector further including a first barrier layer provided on one side of the quantum dot layer and having a larger band gap than the intermediate layer; and a second barrier layer provided on the other side of the quantum dot layer and having a larger band gap than the intermediate layer.Type: ApplicationFiled: August 3, 2009Publication date: February 11, 2010Applicants: TECHNICAL RESEARCH & DEVELOPMENT INSTITUTE MINISTRY OF DEFENSE OF JAPAN, FUJITSU LIMITEDInventors: Toshihiro Okamura, Mitsuhiro Nagashima, Michiya Kibe, Hironori Nishino, Yasuhito Uchiyama, Yusuke Matsukura
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Publication number: 20100032651Abstract: A quantum dot infrared photodetector includes a quantum dot structure including intermediate layers, and a quantum dot layer sandwiched between the intermediate layers and including quantum dots whose energy potential is low for carriers, the intermediate layers and the quantum dots being formed of a III-V compound semiconductor with the V element being As, and an AlAs layer being provided on one of the interfaces between the intermediate layers and the quantum dot layer including the quantum dots and covering at least the quantum dots.Type: ApplicationFiled: August 3, 2009Publication date: February 11, 2010Applicants: TECHNICAL RESEARCH & DEVELOPMENT INSTITUTE MINISTRY OF DEFENSE OF JAPAN, FUJITSU LIMITEDInventors: Toshihiro Okamura, Mitsuhiro Nagashima, Michiya Kibe, Ryo Suzuki, Yasuhito Uchiyama, Hironori Nishino
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Patent number: 7473922Abstract: At least one or more dark current reducing layers having a quantum well structure are provided at an end portion in a stacking direction of an infrared detecting section in which quantum dot layers are stacked.Type: GrantFiled: June 6, 2006Date of Patent: January 6, 2009Assignee: Fujitsu LimitedInventors: Yasuhito Uchiyama, Toshio Fujii, Nobuyuki Kajihara, Hironori Nishino, Yusuke Matsukura
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Publication number: 20070215858Abstract: A photo detector is provided with a plurality of quantum dot layers and first conductive type contact layers provided at both sides of the plurality of quantum dot layers so as to sandwich them; a second conductive type impurity is doped in a first semiconductor layer formed between one first conductive type contact layer and a first quantum dot layer which is closest to the one first conductive type contact layer so that it results in a barrier against a carrier positioned at the one first conductive contact layer.Type: ApplicationFiled: June 14, 2006Publication date: September 20, 2007Applicant: FUJITSU LIMITEDInventors: Yasuhito Uchiyama, Hironori Nishino
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Publication number: 20070131923Abstract: At least one or more dark current reducing layers having a quantum well structure are provided at an end portion in a stacking direction of an infrared detecting section in which quantum dot layers are stacked.Type: ApplicationFiled: June 6, 2006Publication date: June 14, 2007Applicant: FUJITSU LIMITEDInventors: Yasuhito Uchiyama, Toshio Fujii, Nobuyuki Kajihara, Hironori Nishino, Yusuke Matsukura