Patents by Inventor Toyoharu Ohata
Toyoharu Ohata 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).
-
Patent number: 7319052Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: GrantFiled: April 11, 2005Date of Patent: January 15, 2008Assignee: Sony CorporationInventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Patent number: 7049227Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: GrantFiled: April 11, 2005Date of Patent: May 23, 2006Assignee: Sony CorporationInventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Patent number: 7011990Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: GrantFiled: April 11, 2005Date of Patent: March 14, 2006Assignee: Sony CorporationInventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Patent number: 7008827Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: GrantFiled: April 11, 2005Date of Patent: March 7, 2006Assignee: Sony CorporationInventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Publication number: 20050181603Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: ApplicationFiled: April 11, 2005Publication date: August 18, 2005Inventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Publication number: 20050181602Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: ApplicationFiled: April 11, 2005Publication date: August 18, 2005Inventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Publication number: 20050181601Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer, by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: ApplicationFiled: April 11, 2005Publication date: August 18, 2005Inventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Publication number: 20050176190Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: ApplicationFiled: April 11, 2005Publication date: August 11, 2005Inventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Patent number: 6878574Abstract: An alloying method includes steps of forming a metal layer on a semiconductor that is then transferred to a material having a low thermal conductivity. An interface between the semiconductor and the metal layer is formed into an alloy by irradiating the interface with a laser beam having a wavelength that is absorbable in at least one of the semiconductor and the metal layer. Preferably, the material having a low thermal conductivity is a resin or amorphous silicon. Because the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effects on the characteristics of the semiconductor device.Type: GrantFiled: January 14, 2003Date of Patent: April 12, 2005Assignee: Sony CorporationInventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Publication number: 20030170971Abstract: An alloying method includes the steps of forming a metal layer on a semiconductor having been transferred to a material having a low thermal conductivity, and alloying an interface between the semiconductor and the metal layer by irradiating the interface with a laser beam having a wavelength absorbable in at least one of the semiconductor and the metal layer. The irradiation energy of the laser beam is set in a range of 20 to 100 mJ/cm2. The material having a low thermal conductivity is a resin or amorphous silicon. According to the alloying method using laser irradiation, since the entire semiconductor is not heated and only a necessary portion is locally heated, the necessary portion can be readily alloyed to be converted into an ohmic contact without exerting adverse effect on characteristics of the semiconductor device.Type: ApplicationFiled: January 14, 2003Publication date: September 11, 2003Inventors: Katsuhiro Tomoda, Toyoharu Ohata
-
Patent number: 5640409Abstract: A semiconductor light-emitting device capable of emitting blue to green light is disclosed. The device comprises a first cladding layer of the first conduction type stacked on a compound semiconductor substrate and made of ZnMgSSe compound semiconductor; an active layer stacked on the first cladding layer; a second cladding layer of the second conduction type stacked on the active layer and made of a ZnMgSSe compound semiconductor; and ZnSSe compound semiconductor layers provided on the second cladding layer and/or between the compound semiconductor substrate and the first cladding layer. The device has good optical confinement characteristics and carrier confinement characteristics, generates only a small amount of heat during its operation, and is fabricated easily.Type: GrantFiled: January 25, 1996Date of Patent: June 17, 1997Assignee: Sony CorporationInventors: Satoshi Ito, Toyoharu Ohata, Akira Ishibashi, Norikazu Nakayama
-
Patent number: 5515393Abstract: A semiconductor laser using a II-VI compound semiconductor as the material for cladding layers, capable of emitting a blue to green light is disclosed. In an aspect of the semiconductor laser, an n-type ZnSe buffer layer, an n-type ZnMgSSe cladding layer, an active layer made of, for example, ZnCdSe, a p-type ZnMgSSe cladding layer and a p-type ZnSe contact layer are stacked in sequence on an n-type GaAs substrate. A p-side electrode such as an Au/Pd electrode is provided in contact with the p-type ZnSe contact layer. An n-side electrode such as an In electrode is provided on the back surface of the n-type GaAs substrate. In another aspect of the semiconductor laser, an n-type optical guiding layer made of ZnSSe, ZnMgSSe or ZnSe is provided between the n-type ZnMgSSe cladding layer and the active layer, and a p-type optical guiding layer made of ZnSSe, ZnMgSSe or ZnSe is provided between the p-type ZnMgSSe cladding layer and the active layer.Type: GrantFiled: August 4, 1993Date of Patent: May 7, 1996Assignee: Sony CorporationInventors: Hiroyuki Okuyama, Katsuhiro Akimoto, Takao Miyajima, Masafumi Ozawa, Yuko Morinaga, Futoshi Hiei, Kazushi Nakano, Toyoharu Ohata
-
Patent number: 5481558Abstract: According to the present invention, a p-type ZnSe or p-type ZnSSe buffer layer is formed on a p-type GaAs substrate through at least single layer made of AlGaInP-based material and a II/VI-compound laser structure is formed on the p-type ZnSe or p-type ZnSSe buffer layer. Further, an AlGaAs-based buffer layer is provided between the substrate and the AlGaInP-based buffer layer. Further, the AlGaAs-based buffer layer has a composition expressed as Al.sub.0.5 Ga.sub.0.4 As and the AlGaInP-based buffer layer has a composition expressed as Al.sub.0.5 In.sub.0.5 P. Furthermore, a composition ratio x of Al in a buffer layer expressed as Al.sub.x Ga.sub.1-x As is modulated from 0 to 0.6 and a composition ratio y of Al in a buffer layer expressed as (Al.sub.y Ga.sub.1-y).sub.0.5 In.sub.0.5 P is modulated from 0 to 1. According to the present invention, an operation voltage of the II/VI-compound semiconductor laser can be reduced and the green or blue color semiconductor laser of low operation voltage can be obtained.Type: GrantFiled: June 14, 1994Date of Patent: January 2, 1996Assignee: Sony CorporationInventors: Masao Ikeda, Toyoharu Ohata
-
Patent number: 5379314Abstract: A light emitting element comprises a substrate having a {100} crystal face having a ridge extending in a <001> crystal axis direction, a first cladding layer formed on the ridge, an active layer formed on the first cladding layer, a second cladding layer formed on the active layer, a first electrode being electrically connected to the substrate, and a second electrode being electrically connected to the second cladding layer.Type: GrantFiled: October 20, 1993Date of Patent: January 3, 1995Assignee: Sony CorporationInventors: Kazuhiko Nemoto, Toyoharu Ohata, Masamichi Ogawa
-
Patent number: 5373173Abstract: A light emitting element having a semiconductor substrate having {100} crystal surface as a major surface, a light emitting element formed on the semiconductor substrate, a growth blocking layer formed on a resonator end face of the light emitting element, a regrown layer formed on the light emitting element, a reflection mirror opposed to the resonator end face, a first electrode in contact with said semiconductor substrate, and a second electrode formed on the regrown layer, in which the regrown layer is made of the same material as that of the reflection mirror and the reflection mirror is formed of a semiconductor formed of {110} crystal surface epitaxially grown.Type: GrantFiled: May 18, 1993Date of Patent: December 13, 1994Assignee: Sony CorporationInventors: Toyoharu Ohata, Masamichi Ogawa, Kazuhiko Nemoto, Yoshifumi Mori
-
Patent number: 5331659Abstract: An optical semiconductor device in which both of positive input and negative input are possible is disclosed. In the optical semiconductor device, two heterojunction phototransistors are connected in parallel of each other to the cathode of a laser diode. An optical memory in which setting, i.e., writing and resetting, i.e., erasing by light are possible is also disclosed. In the optical memory, two heterojunction phototransistors are connected in parallel of each other to the cathode of a laser diode to make a memory cell.Type: GrantFiled: March 11, 1993Date of Patent: July 19, 1994Assignee: Sony CorporationInventors: Toyoharu Ohata, Kazuhiko Nemoto, Masamichi Ogawa