Patents by Inventor Tetsuroh Murakami
Tetsuroh Murakami 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: 7465962Abstract: A semiconductor light emitting device in the present invention is formed by laminating an epitaxial layer 30 including an AlGaInP active layer and a second wafer 23 which transmits light derived from the active layer. The crystal axes of the epitaxial layer 30 and the second wafer 23 are generally aligned with each other and are in the range of ?15° to +15° with respect to a lateral face {100} of the second wafer 23. This semiconductor light emitting device, which is a joining type with high external emission efficiency, allows uniform wafer bonding to be achieved over the entire wafer face with ease and with a high yield without causing bonding failure and wafer cracks.Type: GrantFiled: June 30, 2006Date of Patent: December 16, 2008Assignee: Sharp Kabushiki KaishaInventors: Eiji Kametani, Yukari Inoguchi, Nobuyuki Watanabe, Tetsuroh Murakami
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Publication number: 20070252158Abstract: A semiconductor light-emitting device has a first conductivity type semiconductor layer, a luminous layer formed on the first conductivity type semiconductor layer, a second conductivity type semiconductor layer formed on the luminous layer, and a transmissive semiconductor layer formed on the second conductivity type semiconductor layer. The transmissive semiconductor layer is pervious to light coming from the luminous layer. The second conductivity type semiconductor layer and the transmissive semiconductor layer have different carrier concentrations, and the carrier concentration of the second conductivity type semiconductor layer is higher than the carrier concentration of the transmissive semiconductor layer.Type: ApplicationFiled: April 26, 2007Publication date: November 1, 2007Applicant: SHARP KABUSHIKI KAISHAInventors: Yukari Inoguchi, Nobuyuki Watanabe, Tetsuroh Murakami, Taeko Chiba
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Patent number: 7285436Abstract: A semiconductor light-emitting device exhibits high reflectance even with less number of pairs of light-reflecting layers, and allows light emitted from the active layer to be effectively extracted outside. This semiconductor light-emitting device is fabricated at good mass productivity by a semiconductor light-emitting device manufacturing method including the step of providing an active layer which generates light having a specified wavelength on a semiconductor substrate. On the semiconductor substrate, are stacked an AlxGa1-xAs layer and the active layer, in this order. Part of the AlxGa1-xAs layer with respect to the is changed into an AlOy layer (where y is a positive real number).Type: GrantFiled: August 17, 2004Date of Patent: October 23, 2007Assignee: Sharp Kabushiki KaishaInventors: Hiroshi Nakatsu, Takahisa Kurahashi, Tetsuroh Murakami, Shouichi Ooyama
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Publication number: 20070194296Abstract: A light emitting diode is composed of a p-type GaP substrate 12 and layers laminated on the p-type GaP substrate 12, including a p-type GaP contact layer 13, a p-type AlInP second cladding layer 14, a p-type AlGaInP active layer 15, an n-type AlInP first cladding layer 16 and an n-type AlGaAs current diffusion layer 17. The entire lateral surfaces of the p-type GaP substrate 12 are processed into a roughened state by a dicing blade. The light emitting diode has high light intensity and its surface can be roughened under any circumstances regardless of its material and orientation so that characteristic failures can be prevented from occurring.Type: ApplicationFiled: February 22, 2007Publication date: August 23, 2007Applicant: SHARP KABUSHIKI KAISHAInventors: Tetsuroh Murakami, Yukari Inoguchi, Nobuyuki Watanabe, Taeko Chiba
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Publication number: 20070023772Abstract: A semiconductor light-emitting device has a first conductivity type semiconductor layer (3, 4), a luminous layer (5) formed on the first conductivity type semiconductor layer, a second conductivity type semiconductor layer (8) formed on the luminous layer, and a transmissive substrate (9) which is formed on the second conductivity type semiconductor layer (8) and is pervious to light coming from the luminous layer (5). The transmissive substrate (9) has a carrier concentration lower than that of the second conductivity type semiconductor layer (8).Type: ApplicationFiled: July 25, 2006Publication date: February 1, 2007Applicant: SHARP KABUSHIKI KAISHAInventors: Nobuyuki Watanabe, Yukari Inoguchi, Tetsuroh Murakami
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Publication number: 20070007543Abstract: A semiconductor light emitting device in the present invention is formed by laminating an epitaxial layer 30 including an AlGaInP active layer and a second wafer 23 which transmits light derived from the active layer. The crystal axes of the epitaxial layer 30 and the second wafer 23 are generally aligned with each other and are in the range of ?15° to +15° with respect to a lateral face {100} of the second wafer 23. This semiconductor light emitting device, which is a joining type with high external emission efficiency, allows uniform wafer bonding to be achieved over the entire wafer face with ease and with a high yield without causing bonding failure and wafer cracks.Type: ApplicationFiled: June 30, 2006Publication date: January 11, 2007Applicant: SHARP KABUSHIKI KAISHAInventors: Eiji Kametani, Yukari Inoguchi, Nobuyuki Watanabe, Tetsuroh Murakami
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Publication number: 20060094140Abstract: A manufacturing method for a semiconductor light emitting device is provided. The method includes preparing a first wafer in which at least one semiconductor layer including the emitter layer is formed; disposing a second wafer transparent to an emission wavelength of the emitter layer on the surface of the first wafer; providing a bonding failure prevention structure to at least either the first wafer or the second wafer for preventing bonding failures of the first wafer and the second wafer; and applying compressive force to a contact face between the first wafer and the second wafer while at the same time, heating the contact face. The first and second wafers can be bonded across their entire surfaces without causing bonding failure.Type: ApplicationFiled: October 31, 2005Publication date: May 4, 2006Applicant: Sharp Kabushiki KaishaInventors: Yukari Inoguchi, Hiroshi Umeda, Takahisa Kurahashi, Nobuyuki Watanabe, Tetsuroh Murakami
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Publication number: 20060054921Abstract: The light emitting diode comprises a p-type AlGaInP active layer 15, a p-type GaAs contact layer for transparent electrode 17, and an ITO transparent electrode 110. The carrier concentration of the p-type GaAs contact layer 17 has been set to 1.0×1019 cm?3.Type: ApplicationFiled: September 9, 2005Publication date: March 16, 2006Applicant: SHARP KABUSHIKI KAISHAInventors: Tetsuroh Murakami, Nobuyuki Watanabe
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Patent number: 6881985Abstract: A light emitting diode (LED) of a double hetero-junction type has a light-emitting layer of a GaAlInP material, a p-type cladding layer and an n-type cladding layer sandwiching the light-emitting layer therebetween, a p-side electrode formed on the p-type cladding layer side, and an n-side electrode formed on the n-type cladding layer side. The p-type cladding layer consists of a first p-type cladding layer positioned closer to the light-emitting layer and having a lower aluminum content and a lower impurity concentration, and a second p-type cladding layer positioned less closer to the light-emitting layer and having a higher aluminum content and a higher impurity concentration. The LED also has a current blocking layer below the p-side electrode for locally blocking electric current flowing from the p-side electrode to the n-side electrode.Type: GrantFiled: July 21, 2003Date of Patent: April 19, 2005Assignee: Sharp Kabushiki KaishaInventors: Tetsuroh Murakami, Takahisa Kurahashi, Hiroshi Nakatsu, Hiroyuki Hosoba
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Patent number: 6864514Abstract: A light emitting diode having, at least, an AlGaInP light emitting layer and a transparent electrode, wherein the transparent electrode is made of a ZnO film doped with a group III element or a compound thereof.Type: GrantFiled: December 3, 2003Date of Patent: March 8, 2005Assignee: Sharp Kabushiki KaishaInventors: Tetsuroh Murakami, Hiroshi Nakatsu, Takahisa Kurahashi, Shouichi Ohyama
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Publication number: 20050012456Abstract: A semiconductor light-emitting device exhibits high reflectance even with less number of pairs of light-reflecting layers, and allows light emitted from the active layer to be effectively extracted outside. This semiconductor light-emitting device is fabricated at good mass productivity by a semiconductor light-emitting device manufacturing method including the step of providing an active layer which generates light having a specified wavelength on a semiconductor substrate. On the semiconductor substrate, are stacked an AlxGa1-xAs layer and the active layer, in this order. Part of the AlxGa1-xAs layer with respect to the is changed into an AlOy layer (where y is a positive real number).Type: ApplicationFiled: August 17, 2004Publication date: January 20, 2005Applicant: SHARP KABUSHIKI KAISHAInventors: Hiroshi Nakatsu, Takahisa Kurahashi, Tetsuroh Murakami, Shouichi Ooyama
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Patent number: 6794688Abstract: A semiconductor light-emitting device exhibits high reflectance even with less number of pairs of light-reflecting layers, and allows light emitted from the active layer to be effectively extracted outside. This semiconductor light-emitting device is fabricated at good mass productivity by a semiconductor light-emitting device manufacturing method including the step of providing an active layer which generates light having a specified wavelength on a semiconductor substrate. On the semiconductor substrate, are stacked an AlxGa1−xAs layer and the active layer, in this order. Part of the AlxGa1−xAs layer with respect to the is changed into an AlOy layer (where y is a positive real number).Type: GrantFiled: September 12, 2002Date of Patent: September 21, 2004Assignee: Sharp Kabushiki KaishaInventors: Hiroshi Nakatsu, Takahisa Kurahashi, Tetsuroh Murakami, Shouici Ooyama
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Patent number: 6770915Abstract: In a semiconductor light-emitting element, a first DBR and a second DBR, with a specified spacing left between them, form a resonator, and a single quantum well active layer is positioned at the loop of a standing wave within this resonator. The single quantum well active layer is composed of a Ga0.5In0.5P well layer and a pair of (Al0.5Ga0.5)0.5In0.5P barrier layers, which sandwiches the Ga0.5In0.5P well layer therebetween. The impurity concentration of the (Al0.5Ga0.5)0.5In0.5P barrier layers is higher than that of the Ga0.5In0.5P well layer. For example, the impurity concentration of the Ga0.5In0.5P well layer is set to 2×1016 cm−3, while the impurity concentration of the (Al0.5Ga0.5)0.5In0.5P barrier layers is set to 2×1018 cm−3.Type: GrantFiled: April 17, 2003Date of Patent: August 3, 2004Assignee: Sharp Kabushiki KaishaInventors: Tetsuroh Murakami, Takahisa Kurahashi, Shouichi Ohyama, Hiroshi Nakatsu
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Publication number: 20040113170Abstract: A light emitting diode having, at least, an AlGaInP light emitting layer and a transparent electrode, wherein the transparent electrode is made of a ZnO film doped with a group III element or a compound thereof.Type: ApplicationFiled: December 3, 2003Publication date: June 17, 2004Applicant: SHARP KABUSHIKI KAISHAInventors: Tetsuroh Murakami, Hiroshi Nakatsu, Takahisa Kurahashi, Shouichi Ohyama
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Publication number: 20040016934Abstract: A light emitting diode (LED) of a double hetero-junction type has a light-emitting layer of a GaAlInP material, a p-type cladding layer and an n-type cladding layer sandwiching the light-emitting layer therebetween, a p-side electrode formed on the p-type cladding layer side, and an n-side electrode formed on the n-type cladding layer side. The p-type cladding layer consists of a first p-type cladding layer positioned closer to the light-emitting layer and having a lower aluminum content and a lower impurity concentration, and a second p-type cladding layer positioned less closer to the light-emitting layer and having a higher aluminum content and a higher impurity concentration. The LED also has a current blocking layer below the p-side electrode for locally blocking electric current flowing from the p-side electrode to the n-side electrode.Type: ApplicationFiled: July 21, 2003Publication date: January 29, 2004Inventors: Tetsuroh Murakami, Takahisa Kurahashi, Hiroshi Nakatsu, Hiroyuki Hosoba
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Publication number: 20030197171Abstract: In a semiconductor light-emitting element, a first DBR and a second DBR, with a specified spacing left between them, form a resonator, and a single quantum well active layer is positioned at the loop of a standing wave within this resonator. The single quantum well active layer is composed of a Ga0.5In0.5P well layer and a pair of (Al0.5Ga0.5)0.5In0.5P barrier layers, which sandwiches the Ga0.5In0.5P well layer therebetween. The impurity concentration of the (Al0.5Ga0.5)0.5In0.5P barrier layers is higher than that of the Ga0.5In0.5P well layer. For example, the impurity concentration of the Ga0.5In0.5P well layer is set to 2×1016 cm−3, while the impurity concentration of the (Al0.5Ga0.5)0.5In0.5P barrier layers is set to 2×1018 cm−3.Type: ApplicationFiled: April 17, 2003Publication date: October 23, 2003Applicant: SHARP KABUSHIKI KAISHAInventors: Tetsuroh Murakami, Takahisa Kurahashi, Shouichi Ohyama, Hiroshi Nakatsu
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Patent number: 6621106Abstract: A light emitting diode (LED) of a double hetero-junction type has a light-emitting layer of a GaAlInP material, a p-type cladding layer and an n-type cladding layer sandwiching the light-emitting layer therebetween, a p-side electrode formed on the p-type cladding layer side, and an n-side electrode formed on the n-type cladding layer side. The p-type cladding layer consists of a first p-type cladding layer positioned closer to the light-emitting layer and having a lower aluminum content and a lower impurity concentration, and a second p-type cladding layer positioned less closer to the light-emitting layer and having a higher aluminum content and a higher impurity concentration. The LED also has a current blocking layer below the p-side electrode for locally blocking electric current flowing from the p-side electrode to the n-side electrode.Type: GrantFiled: January 18, 2001Date of Patent: September 16, 2003Assignee: Sharp Kabushiki KaishaInventors: Tetsuroh Murakami, Takahisa Kurahashi, Hiroshi Nakatsu, Hiroyuki Hosoba
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Publication number: 20030048822Abstract: A semiconductor light-emitting device exhibits high reflectance even with less number of pairs of light-reflecting layers, and allows light emitted from the active layer to be effectively extracted outside. This semiconductor light-emitting device is fabricated at good mass productivity by a semiconductor light-emitting device manufacturing method including the step of providing an active layer which generates light having a specified wavelength on a semiconductor substrate. On the semiconductor substrate, are stacked an AlxGa1−xAs layer and the active layer, in this order. Part of the AlxGa1−xAs layer with respect to the is changed into an AlOy layer (where y is a positive real number).Type: ApplicationFiled: September 12, 2002Publication date: March 13, 2003Applicant: SHARP KABUSHIKI KAISHAInventors: Hiroshi Nakatsu, Takahisa Kurahashi, Tetsuroh Murakami, Shouichi Ooyama
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Patent number: 6465812Abstract: A semiconductor light emitting device of the present invention at least includes: a GaAs substrate whose principal plane is inclined from a (100) plane in a [011] orientation; a first buffer layer of AlxGa1−xAs (0≦x≦1) provided on the principal plane of the GaAs substrate; a second buffer layer of AlyGaxIn1−y−zP (0≦y≦1 and 0≦z≦1) provided on the first buffer layer; a first cladding layer of AlaGatIn1−a−tP (0≦s≦1 and 0≦t≦1) provided on the second buffer layer; an active layer provided on the first cladding layer; and a second cladding layer provided on the active layer, wherein an Al content s of the first cladding layer is larger than an Al content y of the second buffer layer.Type: GrantFiled: September 27, 2000Date of Patent: October 15, 2002Assignee: Sharp Kabushiki KaishaInventors: Hiroyuki Hosoba, Hiroshi Nakatsu, Takahisa Kurahashi, Tetsuroh Murakami, Kazuaki Sasaki, Junichi Nakamura
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Patent number: 6384430Abstract: A light emitting diode includes a substrate, a light emitting layer, a first cladding layer having a first conductivity type and an energy gap greater than an energy gap of the light emitting layer, a second cladding layer having a second conductivity type and an energy gap greater than an energy gap of the light emitting layer, and an intermediate barrier layer having the same conductivity type as the conductivity type of the light emitting layer but different from the conductivity type of the first or second cladding layer, and having an energy gap less than the energy gap of the first or second cladding layer but greater than the energy gap of the light emitting layer. The light emitting diode has a double heterostructure such that the light emitting layer is interposed between the first and second cladding layer. The intermediate barrier layer is disposed between the light emitting layer and the first cladding layer and/or between the light emitting layer and the second cladding layer.Type: GrantFiled: May 10, 2001Date of Patent: May 7, 2002Assignee: Sharp Kabushiki KaishaInventors: Hiroshi Nakatsu, Tetsuroh Murakami, Hiroyuki Hosoba, Takahisa Kurahashi