Patents by Inventor Mitsuru Nakata
Mitsuru Nakata 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: 7724382Abstract: A laser irradiation process includes: scanning a substrate with laser having a predetermined lasing frequency at different irradiation intensities to form a plurality of first irradiation areas corresponding to the irradiation intensities; illuminating the first irradiation areas to reflected light receive from the fist irradiation areas; determining microcrystallization intensity based on the received reflected light; and determining irradiation intensity based on the thus determined microcrystallization intensity. The laser irradiation process uses the irradiation intensity for irradiating a polycrystalline film in a product semiconductor device.Type: GrantFiled: April 19, 2007Date of Patent: May 25, 2010Assignees: NEC Corporation, NEC LCD Technologies, Ltd.Inventors: Mitsuru Nakata, Hirofumi Shimamoto, Hiroshi Kanoh
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Publication number: 20100123132Abstract: To form an oxide semiconductor TFT having a fine property, which can be utilized for driving elements of a display, on a cheap glass substrate or a resin substrate such as PET that is light and flexible with fine regenerability and yield. Through radiating pulse light to an oxide semiconductor, a fine-quality oxide semiconductor film can be formed on a glass substrate or a resin substrate such as PET. This makes it possible to manufacture thin film devices having a fine property with fine regenerability and yield.Type: ApplicationFiled: November 18, 2009Publication date: May 20, 2010Inventors: Mitsuru Nakata, Kazushige Takechi
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Patent number: 7714327Abstract: An electronic device of the present invention includes a first substrate provided with a thin film active element, having a thickness of 200 ?m or lower, and a second substrate formed with a high thermal conductivity portion. The second substrate is applied to one surface of the two surfaces of the first substrate, i.e., the surface being the side other than the side that formed with the thin film active element. The thin film active element has a maximum power consumption of 0.01 to 1 mW. The high thermal conductivity portion is a region that corresponds to the position of the thin film active element and whose thermal conductivity falls within the range from 0.1 to 4 W/cm·deg.Type: GrantFiled: August 23, 2006Date of Patent: May 11, 2010Assignee: NEC CorporationInventors: Kazushige Takechi, Hiroshi Kanou, Mitsuru Nakata
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Publication number: 20100019175Abstract: A manufacturing method of a semiconductor thin film decreases the number of and controls the direction of crystal grain boundaries. A first beam irradiated onto amorphous silicon produces a radial temperature gradient centered on a tip of a concave. This forms a crystal grain in the concave tip, which grows in both the beam width and length direction. After the second beam and on, growth is repeated using the crystal grain formed in the tip of the concave as the seed. This forms a band-form crystal grain with a wider than that of the conventional narrow-line beam, with the tip of the concave being the start point. Further, by setting the periphery of the concave pattern to be equal or less than the crystal grain diameter in the direction vertical to the beam scanning direction, it is possible to form the band-form crystal grain being lined continuously.Type: ApplicationFiled: September 17, 2009Publication date: January 28, 2010Applicant: NEC CORPORATIONInventor: Mitsuru NAKATA
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Semiconductor thin film manufacturing method and device, beam-shaping mask, and thin film transistor
Patent number: 7611577Abstract: A manufacturing method of a semiconductor thin film decreases the number of and controls the direction of crystal grain boundaries. A first beam irradiated onto amorphous silicon produces a radial temperature gradient centered on a tip of a concave. This forms a crystal grain in the concave tip, which grows in both the beam width and length direction. After the second beam and on, growth is repeated using the crystal grain formed in the tip of the concave as the seed. This forms a band-form crystal grain with a wider than that of the conventional narrow-line beam, with the tip of the concave being the start point. Further, by setting the periphery of the concave pattern to be equal or less than the crystal grain diameter in the direction vertical to the beam scanning direction, it is possible to form the band-form crystal grain being lined continuously.Type: GrantFiled: March 31, 2005Date of Patent: November 3, 2009Assignee: NEC CorporationInventor: Mitsuru Nakata -
Patent number: 7579222Abstract: Method of manufacturing a thin film device substrate wherein no trench fabrication is required to be applied onto the substrate surface, and a material which is impervious to light can be used, and the substrate can be peeled off quickly. Firstly, a peeling-off film, a silicon oxide film and an amorphous silicon film are formed in succession on a glass substrate, and the amorphous silicon film is irradiated from above to obtain a polycrystalline silicon film. Subsequently, using the polycrystalline silicon film as an active layer, a TFT is formed, and then a plastic substrate is bonded thereon, and finally the glass substrate is peeled off with the peeling-off film, to complete transfer of the TFT. Because the peeling-off film has a gap space, its etching rate is high. Therefore, it is unnecessary to form a trench for supplying an etchant on the surface of the glass substrate.Type: GrantFiled: August 14, 2006Date of Patent: August 25, 2009Assignee: NEC CorporationInventors: Mitsuru Nakata, Kazushige Takechi, Hiroshi Kanoh
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Publication number: 20080237724Abstract: To provide a semiconductor thin film on which crystal grains with large diameters are formed over a wide range. A beam pattern including a plurality of recessed patterns is scan-irradiated to amorphous silicon in a first scanning direction (first crystallization step). Then, a beam pattern is scan-irradiated in a second scanning direction that is different from the first scanning direction by 90 degrees (second crystallization step). As a result, by having band-shape crystal grains formed in the first crystallization step as seeds, the crystal grain diameters thereof are expanded in the second scanning direction. That is, it is possible to obtain new band-shape crystal grains with the expanded grain diameters.Type: ApplicationFiled: March 19, 2008Publication date: October 2, 2008Applicant: NEC LCD Technologies, Ltd.Inventor: Mitsuru NAKATA
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Publication number: 20080135785Abstract: A method of manufacturing a semiconductor thin film includes (A) forming an amorphous semiconductor film on a substrate, (B) irradiating a beam to a surface of the amorphous semiconductor film such that a predetermined region of the amorphous semiconductor film is melted and solidified to form a crystallized semiconductor film, and (C) scanning the beam in a first direction. A second direction is a direction on the surface of the amorphous semiconductor film perpendicular to the first direction. A length along the second direction of a cross section of the beam is substantially equal to or less than two times a width along the second direction of the crystallized semiconductor film.Type: ApplicationFiled: January 7, 2008Publication date: June 12, 2008Inventors: Hiromichi Takaoka, Mitsuru Nakata
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Patent number: 7354810Abstract: A method of manufacturing a semiconductor thin film includes (A) forming an amorphous semiconductor film on a substrate, (B) irradiating a beam to a surface of the amorphous semiconductor film such that a predetermined region of the amorphous semiconductor film is melted and solidified to form a crystallized semiconductor film, and (C) scanning the beam in a first direction. A second direction is a direction on the surface of the amorphous semiconductor film perpendicular to the first direction. A length along the second direction of a cross section of the beam is substantially equal to or less than two times a width along the second direction of the crystallized semiconductor film.Type: GrantFiled: May 28, 2004Date of Patent: April 8, 2008Assignee: NEC CorporationInventors: Hiromichi Takaoka, Mitsuru Nakata
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Publication number: 20080038882Abstract: A thin-film device includes a first electrical insulator, an oxide-semiconductor film formed on the first electrical insulator, and a second electrical insulator formed on the oxide-semiconductor film, the oxide-semiconductor film defining an active layer. The oxide-semiconductor film is comprised of a first interface layer located at an interface with the first electrical insulating insulator, a second interface layer located at an interface with the second electrical insulator, and a bulk layer other than the first and second interface layers. A density of oxygen holes in at least one of the first and second interlayer layers is smaller than a density of oxygen holes in the bulk layer.Type: ApplicationFiled: August 6, 2007Publication date: February 14, 2008Inventors: Kazushige Takechi, Mitsuru Nakata
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Publication number: 20080035920Abstract: A thin-film transistor array includes an electrically insulating substrate, a plurality of thin-film transistors arranged in a matrix on the substrate, and each including a channel, a source, and a drain each comprised of an oxide-semiconductor film, a pixel electrode integrally formed with the drain, a source signal line through which a source signal is transmitted to a group of thin-film transistors, a gate signal line through which a gate signal is transmitted to a group of thin-film transistors, a source terminal formed at an end of the source signal line, and a gate terminal formed at an end of the gate signal line. The source terminal and the gate terminal are formed in the same layer as a layer in which the channel is formed. The source terminal and the gate terminal have the same electric conductivity as that of the pixel electrode.Type: ApplicationFiled: August 7, 2007Publication date: February 14, 2008Applicants: NEC Corporation, NEC LCD Technologies, Ltd.Inventors: Kazushige Takechi, Mitsuru Nakata
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Publication number: 20070248774Abstract: A printing medium includes: a rectangular lens sheet that has a surface formed in a predetermined lens shape; and a thin base that is fixed to a rear surface of the lens sheet on which no lens is formed and has an extending portion extending from one side of the lens sheet to the outside. In the printing medium, when a region corresponding to the rear surface of the lens sheet is referred to as a unit region, the extending portion includes a plurality of unit regions adjacent to one another with adjacent portions, which are common sides, interposed therebetween, and a first printing surface and a second printing surface having predetermined images formed thereon are formed in corresponding unit regions on one surface of the base that is fixed to the rear surface of the lens sheet or the other surface of the base. In addition, at least one unit region is additionally interposed between the unit region where the first printing surface is formed and the unit region where the second printing surface is formed.Type: ApplicationFiled: April 24, 2007Publication date: October 25, 2007Applicant: SEIKO EPSON CORPORATIONInventors: Katsuhito SUZUKI, Mitsuaki YOSHIZAWA, Mitsuru NAKATA, Fumiaki MUKAIYAMA
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Publication number: 20070249134Abstract: A laser irradiation process includes: scanning a substrate with laser having a predetermined lasing frequency at different irradiation intensities to form a plurality of first irradiation areas corresponding to the irradiation intensities; illuminating the first irradiation areas to reflected light receive from the fist irradiation areas; determining microcrystallization intensity based on the received reflected light; and determining irradiation intensity based on the thus determined microcrystallization intensity. The laser irradiation process uses the irradiation intensity for irradiating a polycrystalline film in a product semiconductor device.Type: ApplicationFiled: April 19, 2007Publication date: October 25, 2007Applicants: NEC CORPORATION, NEC LCD Technologies, Ltd.Inventors: MITSURU NAKATA, Hirofumi Shimamoto, Hiroshi Kanoh
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Patent number: 7256102Abstract: An object of the present invention is to prevent the thin film device formed by laser annealing from making, due to overheat, abnormal operations. Firstly, on a glass substrate 101. a heat insulating film, a silicon oxide film and an amorphous silicon film are formed in succession, and the amorphous silicon film is irradiated from above with a laser beam of an excimer laser. After being molten, the amorphous silicon film undergoes recrystallization to form a polycrystalline silicon film. Subsequently, using the polycrystalline silicon film as an active layer, a TFT is formed, and then a plastic substrate is bonded onto the TFT, and finally the glass substrate is peeled off by way of the heat insulating film, whereby a transfer of the TFT is completed. Because the heat insulating film is removed, abnormality caused by overheat at the time of operation is well prevented from occurring.Type: GrantFiled: November 1, 2004Date of Patent: August 14, 2007Assignee: NEC CorporationInventors: Mitsuru Nakata, Kazushige Takechi, Hiroshi Kanoh
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Publication number: 20070049061Abstract: An electronic device of the present invention includes a first substrate provided with a thin film active element, having a thickness of 200 ?m or lower, and a second substrate formed with a high thermal conductivity portion. The second substrate is applied to one surface of the two surfaces of the first substrate, i.e., the surface being the side other than the side that formed with the thin film active element. The thin film active element has a maximum power consumption of 0.01 to 1 mW. The high thermal conductivity portion is a region that corresponds to the position of the thin film active element and whose thermal conductivity falls within the range from 0.1 to 4 W/cm·deg.Type: ApplicationFiled: August 23, 2006Publication date: March 1, 2007Applicant: NEC CorporationInventors: Kazushige Takechi, Hiroshi Kanou, Mitsuru Nakata
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Publication number: 20060276007Abstract: Method of manufacturing a thin film device substrate wherein no trench fabrication is required to be applied onto the substrate surface, and a material which is impervious to light can be used, and the substrate can be peeled off quickly. Firstly, a peeling-off film, a silicon oxide film and an amorphous silicon film are formed in succession on a glass substrate, and the amorphous silicon film is irradiated from above to obtain a polycrystalline silicon film. Subsequently, using the polycrystalline silicon film as an active layer, a TFT is formed, and then a plastic substrate is bonded thereon, and finally the glass substrate is peeled off with the peeling-off film, to complete transfer of the TFT. Because the peeling-off film has a gap space, its etching rate is high. Therefore, it is unnecessary to form a trench for supplying an etchant on the surface of the glass substrate.Type: ApplicationFiled: August 14, 2006Publication date: December 7, 2006Applicant: NEC CORPORATIONInventors: Mitsuru Nakata, Kazushige Takechi, Hiroshi Kanoh
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Semiconductor thin film manufacturing method and device, beam-shaping mask, and thin film transistor
Publication number: 20050221569Abstract: A manufacturing method of a semiconductor thin film decreases the number of and controls the direction of crystal grain boundaries. A first beam irradiated onto amorphous silicon produces a radial temperature gradient centered on a tip of a concave. This forms a crystal grain in the concave tip, which grows in both the beam width and length direction. After the second beam and on, growth is repeated using the crystal grain formed in the tip of the concave as the seed. This forms a band-form crystal grain with a wider than that of the conventional narrow-line beam, with the tip of the concave being the start point. Further, by setting the periphery of the concave pattern to be equal or less than the crystal grain diameter in the direction vertical to the beam scanning direction, it is possible to form the band-form crystal grain being lined continuously.Type: ApplicationFiled: March 31, 2005Publication date: October 6, 2005Applicant: NEC CORPORATIONInventor: Mitsuru Nakata -
Publication number: 20050095755Abstract: An object of the present invention is to prevent the thin film device formed by laser annealing from making, due to overheat, abnormal operations. Firstly, on a glass substrate 101. a heat insulating film, a silicon oxide film and an amorphous silicon film are formed in succession, and the amorphous silicon film is irradiated from above with a laser beam of an excimer laser. After being molten, the amorphous silicon film undergoes recrystallization to form a polycrystalline silicon film. Subsequently, using the polycrystalline silicon film as an active layer, a TFT is formed, and then a plastic substrate is bonded onto the TFT, and finally the glass substrate is peeled off by way of the heat insulating film, whereby a transfer of the TFT is completed. Because the heat insulating film is removed, abnormality caused by overheat at the time of operation is well prevented from occurring.Type: ApplicationFiled: November 1, 2004Publication date: May 5, 2005Applicant: NEC CORPORATONInventors: Mitsuru Nakata, Kazushige Takechi, Hiroshi Kanoh
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Publication number: 20050003591Abstract: A method of manufacturing a semiconductor thin film includes (A) forming an amorphous semiconductor film on a substrate, (B) irradiating a beam to a surface of the amorphous semiconductor film such that a predetermined region of the amorphous semiconductor film is melted and solidified to form a crystallized semiconductor film, and (C) scanning the beam in a first direction. A second direction is a direction on the surface of the amorphous semiconductor film perpendicular to the first direction. A length along the second direction of a cross section of the beam is substantially equal to or less than two times a width along the second direction of the crystallized semiconductor film.Type: ApplicationFiled: May 28, 2004Publication date: January 6, 2005Inventors: Hiromichi Takaoka, Mitsuru Nakata