Patents by Inventor Yasuhiro Mitani
Yasuhiro Mitani 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: 7804647Abstract: A method for smoothing an annealed surface uses a sub-resolution mask pattern. The method supplies a laser beam having a first wavelength and a mask with a first mask section having apertures with a first dimension and a second mask section with apertures having a second dimension, less than the first dimension. A laser beam having a first energy density is applied to a substrate region, melting a substrate region in response to the first energy density and crystallizing the substrate region. A diffracted laser beam is applied to the substrate region, smoothing the substrate region surface. Applying a diffracted laser beam to the substrate area may include applying a diffracted laser beam having a second energy density, less than the first energy density, to the substrate region.Type: GrantFiled: January 13, 2007Date of Patent: September 28, 2010Assignee: Sharp Laboratories of America, Inc.Inventors: Yasuhiro Mitani, Apostolos T. Voutsas, Mark A. Crowder
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Patent number: 7625785Abstract: A semiconductor device having a crystalline semiconductor film with production of a cavity suppressed and a manufacturing method thereof A manufacturing method of a semiconductor device according to the invention comprises the steps of forming an amorphous silicon film on a substrate having an insulating surface, adding a metal element such as Ni for promoting crystallization to the amorphous silicon film, applying heat treatment to crystallize the amorphous silicon film, so that a crystalline silicon film is formed on the substrate, removing a silicon oxide film formed on the surface of the crystalline silicon film due to the heat treatment by a solution containing organic solvent and fluoride, and irradiating laser light or strong light to the crystalline silicon film.Type: GrantFiled: August 30, 2007Date of Patent: December 1, 2009Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki KaishaInventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
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Publication number: 20080003729Abstract: A semiconductor device having a crystalline semiconductor film with production of a cavity suppressed and a manufacturing method thereof A manufacturing method of a semiconductor device according to the invention comprises the steps of forming an amorphous silicon film on a substrate having an insulating surface, adding a metal element such as Ni for promoting crystallization to the amorphous silicon film, applying heat treatment to crystallize the amorphous silicon film, so that a crystalline silicon film is formed on the substrate, removing a silicon oxide film formed on the surface of the crystalline silicon film due to the heat treatment by a solution containing organic solvent and fluoride, and irradiating laser light or strong light to the crystalline silicon film.Type: ApplicationFiled: August 30, 2007Publication date: January 3, 2008Inventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
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Patent number: 7276402Abstract: A semiconductor device having a crystalline semiconductor film with production of a cavity suppressed and a manufacturing method thereof. A manufacturing method of a semiconductor device according to the invention comprises the steps of forming an amorphous silicon film on a substrate having an insulating surface, adding a metal element such as Ni for promoting crystallization to the amorphous silicon film, applying heat treatment to crystallize the amorphous silicon film, so that a crystalline silicon film is formed on the substrate, removing a silicon oxide film formed on the surface of the crystalline silicon film due to the heat treatment by a solution containing organic solvent and fluoride, and irradiating laser light or strong light to the crystalline silicon film.Type: GrantFiled: December 16, 2004Date of Patent: October 2, 2007Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki KaishaInventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
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Publication number: 20070107655Abstract: A mask with sub-resolution aperture features and a method for smoothing an annealed surface using a sub-resolution mask pattern are provided. The method comprises: supplying a laser beam having a first wavelength; supplying a mask with a first mask section having apertures with a first dimension and a second mask section with apertures having a second dimension, less than the first dimension; applying a laser beam having a first energy density to a substrate region; melting a substrate region in response to the first energy density; crystallizing the substrate region; applying a diffracted laser beam to the substrate region; and, in response to the diffracted laser beam, smoothing the substrate region surface. In some aspects of the method, applying a diffracted laser beam to the substrate area includes applying a diffracted laser beam having a second energy density, less than the first energy density, to the substrate region.Type: ApplicationFiled: January 13, 2007Publication date: May 17, 2007Inventors: Yasuhiro Mitani, Apostolos Voutsas, Mark Crowder
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Patent number: 7192479Abstract: A mask with sub-resolution aperture features and a method for smoothing an annealed surface using a sub-resolution mask pattern are provided. The method comprises: supplying a laser beam having a first wavelength; supplying a mask with a first mask section having apertures with a first dimension and a second mask section with apertures having a second dimension, less than the first dimension; applying a laser beam having a first energy density to a substrate region; melting a substrate region in response to the first energy density; crystallizing the substrate region; applying a diffracted laser beam to the substrate region; and, in response to the diffracted laser beam, smoothing the substrate region surface. In some aspects of the method, applying a diffracted laser beam to the substrate area includes applying a diffracted laser beam having a second energy density, less than the first energy density, to the substrate region.Type: GrantFiled: April 17, 2002Date of Patent: March 20, 2007Assignee: Sharp Laboratories of America, Inc.Inventors: Yasuhiro Mitani, Apostolos T. Voutsas, Mark A. Crowder
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Patent number: 7029961Abstract: A laser annealing mask is provided with cross-hatched sub-resolution aperture patterns. The mask comprises a first section with aperture patterns for transmitting approximately 100% of incident light, and at least one section with cross-hatched sub-resolution aperture patterns for diffracting incident light. In one aspect, a second mask section with cross-hatched sub-resolution aperture patterns has an area adjacent a vertical edge and a third mask section with cross-hatched sub-resolution aperture patterns adjacent the opposite vertical edge, with the first mask section being located between the second and third mask sections. The section with cross-hatched sub-resolution aperture patterns transmits approximately 40% to 70%, and preferably 50% to 60% of incident light energy density. In some aspects, the section with cross-hatched sub-resolution aperture patterns includes a plurality of different cross-hatched aperture patterns.Type: GrantFiled: August 5, 2004Date of Patent: April 18, 2006Assignee: Sharp Laboratories of America, Inc.Inventors: Mark Albert Crowder, Yasuhiro Mitani, Apostolos T. Voutsas
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Patent number: 6959029Abstract: A wide-slit lateral growth projection mask, projection system, and corresponding crystallization process are provided. The mask includes an opaque region with at least one a transparent slit in the opaque region. The slit has a width in the range of 10X to 50X micrometers, with respect to a X:1 demagnification system, and a triangular-shaped slit end. The triangular-shaped slit end has a triangle height and an aspect ratio in the range of 0.5 to 5. The aspect ratio is defined as triangle height/slit width. In some aspects, the triangular-shaped slit end includes one or more opaque blocking features. In another aspect, the triangular-shaped slit end has stepped-shaped sides. The overall effect of the mask is to promote uniformly oriented grain boundaries, even in the film areas annealed under the slit ends.Type: GrantFiled: July 22, 2004Date of Patent: October 25, 2005Assignee: Sharp Laboratories of America, Inc.Inventors: Apostolos T. Voutsas, Mark A. Crowder, Yasuhiro Mitani
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Publication number: 20050142702Abstract: A semiconductor device having a crystalline semiconductor film with production of a cavity suppressed and a manufacturing method thereof. A manufacturing method of a semiconductor device according to the invention comprises the steps of forming an amorphous silicon film on a substrate having an insulating surface, adding a metal element such as Ni for promoting crystallization to the amorphous silicon film, applying heat treatment to crystallize the amorphous silicon film, so that a crystalline silicon film is formed on the substrate, removing a silicon oxide film formed on the surface of the crystalline silicon film due to the heat treatment by a solution containing organic solvent and fluoride, and irradiating laser light or strong light to the crystalline silicon film.Type: ApplicationFiled: December 16, 2004Publication date: June 30, 2005Applicants: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki KaishaInventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
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Publication number: 20050009352Abstract: A laser annealing mask is provided with cross-hatched sub-resolution aperture patterns. The mask comprises a first section with aperture patterns for transmitting approximately 100% of incident light, and at least one section with cross-hatched sub-resolution aperture patterns for diffracting incident light. In one aspect, a second mask section with cross-hatched sub-resolution aperture patterns has an area adjacent a vertical edge and a third mask section with cross-hatched sub-resolution aperture patterns adjacent the opposite vertical edge, with the first mask section being located between the second and third mask sections. The section with cross-hatched sub-resolution aperture patterns transmits approximately 40% to 70%, and preferably 50% to 60% of incident light energy density. In some aspects, the section with cross-hatched sub-resolution aperture patterns includes a plurality of different cross-hatched aperture patterns.Type: ApplicationFiled: August 5, 2004Publication date: January 13, 2005Inventors: Mark Crowder, Yasuhiro Mitani, Apostolos Voutsas
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Publication number: 20040259296Abstract: A wide-slit lateral growth projection mask, projection system, and corresponding crystallization process are provided. The mask includes an opaque region with at least one a transparent slit in the opaque region. The slit has a width in the range of 10X to 50X micrometers, with respect to a X:1 demagnification system, and a triangular-shaped slit end. The triangular-shaped slit end has a triangle height and an aspect ratio in the range of 0.5 to 5. The aspect ratio is defined as triangle height/slit width. In some aspects, the triangular-shaped slit end includes one or more opaque blocking features. In another aspect, the triangular-shaped slit end has stepped-shaped sides. The overall effect of the mask is to promote uniformly oriented grain boundaries, even in the film areas annealed under the slit ends.Type: ApplicationFiled: July 22, 2004Publication date: December 23, 2004Applicant: Sharp Laboratories of America, Inc.Inventors: Apostolos T. Voutsas, Mark A. Crowder, Yasuhiro Mitani
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Patent number: 6777276Abstract: A laser annealing mask is provided with cross-hatched sub-resolution aperture patterns. The mask comprises a first section with aperture patterns for transmitting approximately 100% of incident light, and at least one section with cross-hatched sub-resolution aperture patterns for diffracting incident light. In one aspect, a second mask section with cross-hatched sub-resolution aperture patterns has an area adjacent a vertical edge and a third mask section with cross-hatched sub-resolution aperture patterns adjacent the opposite vertical edge, with the first mask section being located between the second and third mask sections. The section with cross-hatched sub-resolution aperture patterns transmits approximately 40% to 70%, and preferably 50% to 60% of incident light energy density. In some aspects, the section with cross-hatched sub-resolution aperture patterns includes a plurality of different cross-hatched aperture patterns.Type: GrantFiled: August 29, 2002Date of Patent: August 17, 2004Assignee: Sharp Laboratories of America, Inc.Inventors: Mark Albert Crowder, Yasuhiro Mitani, Apostolos T. Voutsas
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Publication number: 20040043606Abstract: A laser annealing mask is provided with cross-hatched sub-resolution aperture patterns. The mask comprises a first section with aperture patterns for transmitting approximately 100% of incident light, and at least one section with cross-hatched sub-resolution aperture patterns for diffracting incident light. In one aspect, a second mask section with cross-hatched sub-resolution aperture patterns has an area adjacent a vertical edge and a third mask section with cross-hatched sub-resolution aperture patterns adjacent the opposite vertical edge, with the first mask section being located between the second and third mask sections. The section with cross-hatched sub-resolution aperture patterns transmits approximately 40% to 70%,, and preferably 50% to 60% of incident light energy density. In some aspects, the section with cross-hatched sub-resolution aperture patterns includes a plurality of different cross-hatched aperture patterns.Type: ApplicationFiled: August 29, 2002Publication date: March 4, 2004Inventors: Mark Albert Crowder, Yasuhiro Mitani, Apostolos T. Voutsas
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Publication number: 20030196589Abstract: A mask with sub-resolution aperture features and a method for smoothing an annealed surface using a sub-resolution mask pattern are provided. The method comprises: supplying a laser beam having a first wavelength; supplying a mask with a first mask section having apertures with a first dimension and a second mask section with apertures having a second dimension, less than the first dimension; applying a laser beam having a first energy density to a substrate region; melting a substrate region in response to the first energy density; crystallizing the substrate region; applying a diffracted laser beam to the substrate region; and, in response to the diffracted laser beam, smoothing the substrate region surface. In some aspects of the method, applying a diffracted laser beam to the substrate area includes applying a diffracted laser beam having a second energy density, less than the first energy density, to the substrate region.Type: ApplicationFiled: April 17, 2002Publication date: October 23, 2003Inventors: Yasuhiro Mitani, Apostolos T. Voutsas, Mark A. Crowder
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Patent number: 6607971Abstract: A method for an efficient extended pulse laser annealing process is provided. The method comprises: supplying a substrate with a thickness; selecting an energy density; selecting an extended pulse duration; laser annealing a substrate region; in response to cooling the substrate region, crystallizing the substrate region; and, efficiently extending the lateral growth of crystals in the substrate region. When the substrate has a thickness of approximately 300 Å, the energy density is selected to be in the range of 400 to 500 millijoules pre square centimeter (mJ/cm2). The pulse duration is selected to be in the range between 70 and 120 nanoseconds (ns). More preferably, the pulse duration is selected to be in the range between 90 and 120 ns. Most preferable, the pulse duration is approximately 100 ns. Then, efficiently extending the lateral growth of crystals in the substrate region includes laterally growing crystals at a rate of approximately 0.029 microns per nanosecond.Type: GrantFiled: April 30, 2002Date of Patent: August 19, 2003Assignee: Sharp Laboratories of America, Inc.Inventors: Masao Moriguchi, Apostolos T. Voutsas, Yasuhiro Mitani
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Patent number: 5821562Abstract: Into an amorphous silicon film, catalyst elements for accelerating the crystallization are introduced. After patterning the amorphous silicon films in which the catalyst elements have been introduced into an island pattern, a heat treatment for the crystallization is conducted. Thus, the introduced catalyst elements efficiently diffuse only inside the island-patterned amorphous silicon films. As a result, a high-quality crystalline silicon film, having the crystal growth direction aligned in one direction and having no grain boundaries, is obtained. Using the thus formed crystalline silicon film, semiconductor devices having a high performance and stable characteristics are fabricated efficiently over the entire substrate, irrespective of the size of the devices.Type: GrantFiled: May 30, 1995Date of Patent: October 13, 1998Assignee: Sharp Kabushiki KaishaInventors: Naoki Makita, Takashi Funai, Yoshitaka Yamamoto, Yasuhiro Mitani, Katsumi Nomura, Tadayoshi Miyamoto, Takamasa Kosai
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Patent number: 5696003Abstract: Into an amorphous silicon film, catalyst elements for accelerating the crystallization are introduced. After patterning the amorphous silicon films in which the catalyst elements have been introduced into an island pattern, a heat treatment for the crystallization is conducted. Thus, the introduced catalyst elements efficiently diffuse only inside the island-patterned amorphous silicon films. As a result, a high-quality crystalline silicon film, having the crystal growth direction aligned in one direction and having no grain boundaries, is obtained. Using the thus formed crystalline silicon film, semiconductor devices having a high performance and stable characteristics are fabricated efficiently over the entire substrate, irrespective of the size of the devices.Type: GrantFiled: December 16, 1994Date of Patent: December 9, 1997Assignee: Sharp Kabushiki KaishaInventors: Naoki Makita, Takashi Funai, Yoshitaka Yamamoto, Yasuhiro Mitani, Katsumi Nomura, Tadayoshi Miyamoto, Takamasa Kosai
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Patent number: 5474941Abstract: A method for producing an active matrix substrate using a thin film transistor having a gate electrode on an insulating substrate covered with a gate insulating layer, a semiconductor layer on the gate insulating layer, a channel protective layer on the semiconductor layer, a drain electrode having a portion overlying the gate electrode with the interposition of the gate insulating layer, the semiconductor layer and the channel protective layer, and a source electrode having a portion overlying the gate electrode with the interposition of the gate insulating layer, the method enhancing the transistor characteristics of the active matrix substrate with minimum leakage and the removal of an off-current generated from the presence of electrons and holes.Type: GrantFiled: November 18, 1993Date of Patent: December 12, 1995Assignee: Sharp Kabushiki KaishaInventors: Yasuhiro Mitani, Hirohisa Tanaka, Hirosshi Morimoto, Tomohiko Yamamoto
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Patent number: 5286659Abstract: A method for producing an active matrix substrate using a thin film transistor having a gate electrode on an insulating substrate covered with a gate insulating layer, a semiconductor layer on the gate insulating layer, a channel protective layer on the semiconductor layer, a drain electrode having a portion overlying the gate electrode with the interposition of the gate insulating layer, the semiconductor layer and the channel protective layer, and a source electrode having a portion overlying the gate electrode with the interposition of the gate insulating layer, the method enhancing the transistor characteristics of the active matrix substrate with minimum leakage and the removal of an off-current generated from the presence of electrons and holes.Type: GrantFiled: December 26, 1991Date of Patent: February 15, 1994Assignee: Sharp Kabushiki KaishaInventors: Yasuhiro Mitani, Katsumara Ikubo, Yasunori Shimada, Hirohisa Tanaka, Hiroshi Morimoto, Yutaka Nishi, Tomohiko Yamamoto, Kenichi Nishimura