Patents by Inventor Yasuhisa Oana
Yasuhisa Oana 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: 7348598Abstract: A TFT, in which source and drain electrodes having concentric circular shapes are formed, reduces an OFF current caused by a leakage current and optimizes an ON current and a stray capacitance between gate and source electrodes. The TFT includes a gate electrode formed on a substrate; and source and drain electrodes obtained by sequentially forming a gate insulating film, an intrinsic amorphous silicon layer, and an n+ amorphous silicon layer on the gate electrode, wherein the source and drain electrodes have circular shapes. One of the source and drain electrodes is disposed at the center, and the other one of the source and drain electrodes having a concentric circular shape surrounds the former. A channel region may be formed between the source and drain electrodes; and an area of an effective stray capacitance may be less than 150 ?m2. A ratio of a width of a channel to a length of the channel may be more than 4.5 and a filling capacity index to the effective stray capacitance may be less than 50.Type: GrantFiled: April 28, 2006Date of Patent: March 25, 2008Assignee: LG.Philips LCD Co., Ltd.Inventor: Yasuhisa Oana
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Publication number: 20060262239Abstract: A TFT, in which source and drain electrodes having concentric circular shapes are formed, reduces an OFF current caused by a leakage current and optimizes an ON current and a stray capacitance between gate and source electrodes. The TFT includes a gate electrode formed on a substrate; and source and drain electrodes obtained by sequentially forming a gate insulating film, an intrinsic amorphous silicon layer, and an n+ amorphous silicon layer on the gate electrode, wherein the source and drain electrodes have circular shapes. One of the source and drain electrodes is disposed at the center, and the other one of the source and drain electrodes having a concentric circular shape surrounds the former. A channel region may be formed between the source and drain electrodes; and an area of an effective stray capacitance may be less than 150 ?m2. A ratio of a width of a channel to a length of the channel may be more than 4.5 and a filling capacity index to the effective stray capacitance may be less than 50.Type: ApplicationFiled: April 28, 2006Publication date: November 23, 2006Applicant: L.G.PHILIPS LCD CO., LTD.Inventor: Yasuhisa Oana
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Patent number: 7067404Abstract: A thin film semiconductor device includes a gate electrode insulator formed through high-heat oxidization of a semiconductor film. The high-heat oxidization of semiconductor film is carried out, in the process of crystallization or recrystallization of non-single-crystalline semiconductor thin film on a base layer, by irradiating predetermined areas of the thin film which is implanted with oxygen ion before irradiation, to convert such areas to oxidized areas, and these areas are processed to gate electrode insulators of electric circuit units in the thin film semiconductor device.Type: GrantFiled: January 6, 2005Date of Patent: June 27, 2006Assignee: Advanced LCD Technologies Development Center Co., Ltd.Inventors: Yasuhisa Oana, Masakiyo Matsumura
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Publication number: 20050121111Abstract: A thin film semiconductor device includes a gate electrode insulator formed through high-heat oxidization of a semiconductor film. The high-heat oxidization of semiconductor film is carried out, in the process of crystallization or recrystallization of non-single-crystalline semiconductor thin film on a base layer, by irradiating predetermined areas of the thin film which is implanted with oxygen ion before irradiation, to convert such areas to oxidized areas, and these areas are processed to gate electrode insulators of electric circuit units in the thin film semiconductor device.Type: ApplicationFiled: January 6, 2005Publication date: June 9, 2005Inventors: Yasuhisa Oana, Masakiyo Matsumura
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Publication number: 20050085002Abstract: A thin film semiconductor device and a method for producing it are described. In the thin film layer of semiconductor of the device, a plurality of large size single-crystalline grains of semiconductor are formed in a regulated configuration, and each of single crystalline grains is equipped with one unit of electric circuit having a gate electrode, a source electrode and drain electrode. Such regulated arrangement of large size single-crystalline grains in the semiconductor layer is realized by a process including a step of irradiating the layer of amorphous or polycrystalline semiconductor with energy beam such as excimer laser so that maximum irradiation intensity points and minimum irradiation intensity points are arranged regulatedly. The device can have a high mobility such as about 500 cm2/V sec.Type: ApplicationFiled: October 29, 2004Publication date: April 21, 2005Applicant: Advanced LCD Technologies Development Center, Co, Ltd.Inventors: Masakiyo Matsumura, Yasuhisa Oana, Hiroyuki Abe, Yoshitaka Yamamoto, Hideo Koseki, Mitsunori Warabisako
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Patent number: 6828178Abstract: A thin film semiconductor device and a method for producing it are described. In the thin film layer of semiconductor of the device, a plurality of large size single-crystalline grains of semiconductor are formed in a regulated configuration, and each of single crystalline grains is equipped with one unit of electric circuit having a gate electrode, a source electrode and drain electrode. Such regulated arrangement of large size single-crystalline grains in the semiconductor layer is realized by a process including a step of irradiating the layer of amorphous or polycrystalline semiconductor with energy beam such as excimer laser so that maximum irradiation intensity points and minimum irradiation intensity points are arranged regulatedly. The device can have a high mobility such as about 500 cm2/V sec.Type: GrantFiled: July 11, 2002Date of Patent: December 7, 2004Assignee: Advanced LCD Technologies Development Center Co., Ltd.Inventors: Masakiyo Matsumura, Yasuhisa Oana, Hiroyuki Abe, Yoshitaka Yamamoto, Hideo Koseki, Mitsunori Warabisako
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Publication number: 20030071312Abstract: A thin film semiconductor device includes a gate electrode insulator formed through high-heat oxidization of a semiconductor film. The high-heat oxidization of semiconductor film is carried out, in the process of crystallization or recrystallization of non-single-crystalline semiconductor thin film on a base layer, by irradiating predetermined areas of the thin film which is implanted with oxygen ion before irradiation, to convert such areas to oxidized areas, and these areas are processed to gate electrode insulators of electric circuit units in the thin film semiconductor device.Type: ApplicationFiled: September 6, 2002Publication date: April 17, 2003Inventors: Yasuhisa Oana, Masakiyo Matsumura
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Publication number: 20030027410Abstract: A thin film semiconductor device and a method for producing it are described. In the thin film layer of semiconductor of the device, a plurality of large size single-crystalline grains of semiconductor are formed in a regulated configuration, and each of single crystalline grains is equipped with one unit of electric circuit having a gate electrode, a source electrode and drain electrode. Such regulated arrangement of large size single-crystalline grains in the semiconductor layer is realized by a process including a step of irradiating the layer of amorphous or polycrystalline semiconductor with energy beam such as excimer laser so that maximum irradiation intensity points and minimum irradiation intensity points are arranged regulatedly. The device can have a high mobility such as about 500 cm2/V sec..Type: ApplicationFiled: July 11, 2002Publication date: February 6, 2003Applicant: ALTEDECInventors: Masakiyo Matsumura, Yasuhisa Oana, Hiroyuki Abe, Yoshitaka Yamamoto, Hideo Koseki, Mitsunori Warabisako
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Patent number: 6372083Abstract: In manufacturing a thin-film transistor on a glass substrate, a first thin film consisting of an amorphous silicon thin film is formed on the glass substrate, and a second thin film is formed on the first thin film. Then, this second thin film is etched to form a mask pattern. A dopant ion is doped into the first thin film through the mask pattern to form a source region and a drain region. The process of forming the mask pattern and the process of forming the source and drain regions are carried out continuously without exposing the substrate to the atmosphere.Type: GrantFiled: September 29, 2000Date of Patent: April 16, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhisa Oana, Kaichi Fukuda, Takayoshi Dohi
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Patent number: 6146929Abstract: In manufacturing a thin-film transistor on a glass substrate, a first thin film consisting of an amorphous silicon thin film is formed on the glass substrate, and a second thin film is formed on the first thin film. Then, this second thin film is etched to form a mask pattern. A dopant ion is doped into the first thin film through the mask pattern to form a source region and a drain region. The process of forming the mask pattern and the process of forming the source and drain regions are carried out continuously without exposing the substrate to the atmosphere.Type: GrantFiled: July 9, 1999Date of Patent: November 14, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhisa Oana, Kaichi Fukuda, Takayoshi Dohi
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Patent number: 6008869Abstract: The present invention provides a display device substrate includes a first wiring layer formed on a substrate made of an insulating material, a second wiring layer formed to cross the first wiring layer, and an insulating film interposed between the first and second wiring layers at a cross point portion therebetween, wherein the first wiring layer is constituted by an electrode wiring layer made of a material containing aluminum as a main component and a surface covering layer formed by causing a refractory metal to denature the electrode wiring layer.Type: GrantFiled: December 13, 1995Date of Patent: December 28, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhisa Oana, Nobuki Ibaraki, Masayuki Dohjo, Yoshitaka Kamata
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Patent number: 5227901Abstract: A liquid crystal display device includes first and second substrate and a liquid crystal layer sealed between the substrates. A plurality of pixel elements are formed in a matrix pattern on the first substrate, and a plurality of driving nonlinear resistance elements are formed on the first substrate and electrically connected to the pixel electrodes, respectively. A plurality of parallel wiring electrodes are formed on the first substrate, respectively extending in parallel to the columns of the pixel electrodes, and electrically connected to the respective nonlinear resistance elements on the respective columns of the pixel electrodes. Each wiring electrode is divided at a dividing portion and has a pair of divided ends. Protecting nonlinear resistance elements are respectively formed on the divided ends of each wiring electrode so as to reduce potential difference between the divided ends when static electricity is generated at the dividing portions.Type: GrantFiled: March 19, 1992Date of Patent: July 13, 1993Assignee: Kabushiki Kaisha ToshibaInventors: Tetsuya Iizuka, Shinichi Kamagami, Yasuhisa Oana
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Patent number: 5170244Abstract: There is provided a semiconductor device using a molybdenum-tantalum alloy having a tantalum composition ratio of 30 to 84 atomic percent. Using this Mo-Ta alloy, there is provided an electrode interconnection material comprising a multi-layered structure having an underlying metal film having a crystalline form of a body-centered cubic system and overlying a molybdenum-tantalum alloy film having a tantalum composition ratio of above 84 atomic percent.Type: GrantFiled: April 8, 1991Date of Patent: December 8, 1992Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Dohjo, Yasuhisa Oana, Mitsushi Ikeda
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Patent number: 5142392Abstract: Disclosed is a color liquid crystal display device having a plurality of pixels, in which conductive films are arranged at regions corresponding to the respective pixels, a light-shielding conductive layer is connected to the conductive films and extends in a region between the pixels, and color filters are formed on the conductive films.Type: GrantFiled: April 30, 1991Date of Patent: August 25, 1992Assignees: International Business Machines Corporation, Kabushiki Kaisha ToshibaInventors: Toshihiro Ueki, Yasuhisa Oana, Hitoshi Tomii
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Patent number: 5083853Abstract: Disclosed is a color liquid crystal display device having a plurality of pixels, in which conductive films are arranged at regions corresponding to the respective pixels, a light-shielding conductive layer is connected to the conductive films and extends in a region between the pixels, and color filters are formed on the conductive films.Type: GrantFiled: September 20, 1988Date of Patent: January 28, 1992Assignees: International Business Machines Corporation, Kabushiki Kaisha ToshibaInventors: Toshihiro Ueki, Yasuhisa Oana, Hitoshi Tomii
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Patent number: 5028551Abstract: There is provided a semiconductor device using a molybdenum-tantalum alloy having a tantalum composition ratio of 30 to 84 atomic percent. Using this Mo-Ta alloy, there is provided an electrode interconnection material comprising a multi-layered structure having an underlying metal film having a crystalline form of a body-centered cubic system and overlying a molybdenum-tantalum alloy film having a tantalum composition ratio of above 84 atomic percent.Type: GrantFiled: May 9, 1990Date of Patent: July 2, 1991Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Dohjo, Yasuhisa Oana, Mitsushi Ikeda
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Patent number: 4975760Abstract: There is provided a semiconductor device using a molybdenum-tantalum alloy having a tantalum composition ratio of 30 to 84 atomic percent. Using this Mo-Ta alloy, there is provided an electrode interconnection material comprising a multi-layered structure having an underlying metal film having a crystalline form of a body-centered cubic system and overlying a molybdenum-tantalum alloy film having a tantalum composition ratio of above 84 atomic percent.Type: GrantFiled: September 25, 1989Date of Patent: December 4, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Dohjo, Yasuhisa Oana, Mitsushi Ikeda
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Patent number: 4963240Abstract: The present invention is a sputtering target for formation of an alloy film, which comprises 15 to 50 atomic percent of molybdenum or tungsten, the remaining atomic percent of tantalum, and concomitant impurities, which can provide electrical wiring having very low specific resistance as well as excellent workability and stability, whereby high definition and high integration of various elements such as semiconductor devices can be achieved. In consequence, it is fair to say that this invention is industrially very useful.Type: GrantFiled: March 29, 1988Date of Patent: October 16, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Yoshiharu Fukasawa, Mituo Kawai, Hideo Ishihara, Takenori Umeki, Yasuhisa Oana
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Patent number: 4946259Abstract: A color liquid crystal display comprises a liquid crystal interposed between two transparent electrodes. The electrode on at least one side of the liquid crystal comprises a plurality of pixel electrodes, each pixel electrode defining the area of one pixel of the display. Two or more pixels together form a picture element of the color display. One pixel (a chromatic pixel) of each picture element has a color filter covering the pixel. The other pixel (an achromatic pixel) of each picture element has a translucent (noncolored) filter covering the pixel. The translucent filter also covers a peripheral region of each color pixel. The peripheral region of each chromatic pixel (which is covered by both the color filter and the translucent filter) forms a light shield to increase the contrast of the display. A transparent (noncolored) filter is provided over each achromatic pixel to adjust the overall thickness of the liquid crystal, so as to minimize light leakage at the achromatic pixels.Type: GrantFiled: January 24, 1990Date of Patent: August 7, 1990Assignee: International Business Machines CorporationInventors: Haruhiro Matino, Toshihiro Ueki, Yasuhisa Oana, Motoji Kajimura
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Patent number: 4905066Abstract: A thin-film transistor comprising a substrate, a gate electrode formed on said substrate and made of molybdenum-tantalum alloy containing 60 to 85 atomic % of tantalum gate insulation film formed on said gate electrode and made of a laminated layer including silicon nitride film and oxide film formed by oxidizing the surface of said gate electrode, semiconductor film formed on said gate insulation film and contacting the silicon nitride film, and source and drain electrodes formed on the semiconductor film.Type: GrantFiled: April 19, 1989Date of Patent: February 27, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Masayuki Dohjo, Yasuhisa Oana, Mitsushi Ikeda