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).

  • Patent number: 7804647
    Abstract: 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: Grant
    Filed: January 13, 2007
    Date of Patent: September 28, 2010
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Yasuhiro Mitani, Apostolos T. Voutsas, Mark A. Crowder
  • Patent number: 7625785
    Abstract: 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: Grant
    Filed: August 30, 2007
    Date of Patent: December 1, 2009
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
  • Publication number: 20080003729
    Abstract: 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: Application
    Filed: August 30, 2007
    Publication date: January 3, 2008
    Inventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
  • Patent number: 7276402
    Abstract: 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: Grant
    Filed: December 16, 2004
    Date of Patent: October 2, 2007
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
  • Publication number: 20070107655
    Abstract: 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: Application
    Filed: January 13, 2007
    Publication date: May 17, 2007
    Inventors: Yasuhiro Mitani, Apostolos Voutsas, Mark Crowder
  • Patent number: 7192479
    Abstract: 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: Grant
    Filed: April 17, 2002
    Date of Patent: March 20, 2007
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Yasuhiro Mitani, Apostolos T. Voutsas, Mark A. Crowder
  • Patent number: 7029961
    Abstract: 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: Grant
    Filed: August 5, 2004
    Date of Patent: April 18, 2006
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Mark Albert Crowder, Yasuhiro Mitani, Apostolos T. Voutsas
  • Patent number: 6959029
    Abstract: 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: Grant
    Filed: July 22, 2004
    Date of Patent: October 25, 2005
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Apostolos T. Voutsas, Mark A. Crowder, Yasuhiro Mitani
  • Publication number: 20050142702
    Abstract: 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: Application
    Filed: December 16, 2004
    Publication date: June 30, 2005
    Applicants: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Hideto Ohnuma, Masayuki Sakakura, Yasuhiro Mitani, Takuya Matsuo, Hidehito Kitakado
  • Publication number: 20050009352
    Abstract: 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: Application
    Filed: August 5, 2004
    Publication date: January 13, 2005
    Inventors: Mark Crowder, Yasuhiro Mitani, Apostolos Voutsas
  • Publication number: 20040259296
    Abstract: 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: Application
    Filed: July 22, 2004
    Publication date: December 23, 2004
    Applicant: Sharp Laboratories of America, Inc.
    Inventors: Apostolos T. Voutsas, Mark A. Crowder, Yasuhiro Mitani
  • Patent number: 6777276
    Abstract: 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: Grant
    Filed: August 29, 2002
    Date of Patent: August 17, 2004
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Mark Albert Crowder, Yasuhiro Mitani, Apostolos T. Voutsas
  • Publication number: 20040043606
    Abstract: 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: Application
    Filed: August 29, 2002
    Publication date: March 4, 2004
    Inventors: Mark Albert Crowder, Yasuhiro Mitani, Apostolos T. Voutsas
  • Publication number: 20030196589
    Abstract: 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: Application
    Filed: April 17, 2002
    Publication date: October 23, 2003
    Inventors: Yasuhiro Mitani, Apostolos T. Voutsas, Mark A. Crowder
  • Patent number: 6607971
    Abstract: 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: Grant
    Filed: April 30, 2002
    Date of Patent: August 19, 2003
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Masao Moriguchi, Apostolos T. Voutsas, Yasuhiro Mitani
  • Patent number: 5821562
    Abstract: 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: Grant
    Filed: May 30, 1995
    Date of Patent: October 13, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoki Makita, Takashi Funai, Yoshitaka Yamamoto, Yasuhiro Mitani, Katsumi Nomura, Tadayoshi Miyamoto, Takamasa Kosai
  • Patent number: 5696003
    Abstract: 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: Grant
    Filed: December 16, 1994
    Date of Patent: December 9, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoki Makita, Takashi Funai, Yoshitaka Yamamoto, Yasuhiro Mitani, Katsumi Nomura, Tadayoshi Miyamoto, Takamasa Kosai
  • Patent number: 5474941
    Abstract: 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: Grant
    Filed: November 18, 1993
    Date of Patent: December 12, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuhiro Mitani, Hirohisa Tanaka, Hirosshi Morimoto, Tomohiko Yamamoto
  • Patent number: 5286659
    Abstract: 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: Grant
    Filed: December 26, 1991
    Date of Patent: February 15, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuhiro Mitani, Katsumara Ikubo, Yasunori Shimada, Hirohisa Tanaka, Hiroshi Morimoto, Yutaka Nishi, Tomohiko Yamamoto, Kenichi Nishimura