Patents by Inventor Masakazu Saito

Masakazu Saito 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).

  • Publication number: 20060118036
    Abstract: To improve the laser annealing process for polycrystallizing amorphous silicon to form silicon thin films having large crystal particle diameters at a high throughput, the present invention is directed to a process of crystallization by irradiation of a semiconductor thin film formed on a substrate with pulsed laser light. The process comprises having a means to shape laser light into a linear beam and a means to periodically and spatially modulate the intensity of pulsed laser in the direction of the long axis of the linear beam by passing through a phase-shifting stripy pattern perpendicular to the long axis, and collectively forming for each shot a polycrystalline film composed of crystals which have grown in a certain direction over the entire region irradiated with the linear beam.
    Type: Application
    Filed: January 31, 2006
    Publication date: June 8, 2006
    Inventors: Kazuo Takeda, Jun Gotou, Masakazu Saito, Makoto Ohkura, Takeshi Satou, Hiroshi Fukuda, Takeo Shiba
  • Publication number: 20060110869
    Abstract: A display device includes a pixel region having a plurality of pixels and a peripheral circuit region disposed at a periphery of the pixel region for driving the pixels. The peripheral circuit region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a first kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the first kind is at least 3 ?m. The pixel region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a second kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the second kind is at least 0.05 ?m.
    Type: Application
    Filed: August 16, 2005
    Publication date: May 25, 2006
    Inventors: Kenkichi Suzuki, Tetsuya Nagata, Michiko Takahashi, Masakazu Saito, Toshio Ogino, Masanobu Miyano
  • Patent number: 7022183
    Abstract: To improve the laser annealing process for polycrystallizing amorphous silicon to form silicon thin films having large crystal particle diameters at a high throughput, the present invention is directed to a process of crystallization by irradiation of a semiconductor thin film formed on a substrate with pulsed laser light. The process comprises having a means to shape laser light into a linear beam and a means to periodically and spatially modulate the intensity of pulsed laser in the direction of the long axis of the linear beam by passing through a phase-shifting stripy pattern perpendicular to the long axis, and collectively forming for each shot a polycrystalline film composed of crystals which have grown in a certain direction over the entire region irradiated with the linear beam.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: April 4, 2006
    Assignee: Hiatchi, Ltd.
    Inventors: Kazuo Takeda, Jun Gotou, Masakazu Saito, Makoto Ohkura, Takeshi Satou, Hiroshi Fukuda, Takeo Shiba
  • Patent number: 7022558
    Abstract: The present invention provides a manufacturing method of a high performance active matrix substrate at a high throughput with a less expensive apparatus, and an image display device using the active matrix substrate. On a stage moving in the short axis direction X and long axis direction Y on a rail, a glass substrate is carried, which has an amorphous silicon semiconductor film formed. Polycrystallized and large grain silicon film may be obtained by intensity modulating the pulsed laser beam in a line beam shape by means of a phase shift mask with a periodicity in the long axis direction Y of the laser beam, moving the laser beam randomly in the modulation direction of the amorphous silicon semiconductor film formed on the glass substrate to expose to crystallize the film. The image display device may incorporate an active matrix substrate having active elements such as thin film transistors formed by this silicon film.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: April 4, 2006
    Assignees: Hitachi, Ltd., Hitachi Displays, Ltd.
    Inventors: Takeshi Sato, Kazuo Takeda, Masakazu Saito, Jun Goto, Makoto Ohkura
  • Patent number: 6965122
    Abstract: A display device includes a pixel region having a plurality of pixels and a peripheral circuit region disposed at a periphery of the pixel region for driving the pixels. The peripheral circuit region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a first kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the first kind is at least 3 ?m. The pixel region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a second kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the second kind is at least 0.05 ?m.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: November 15, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Kenkichi Suzuki, Tetsuya Nagata, Michiko Takahashi, Masakazu Saito, Toshio Ogino, Masanobu Miyano
  • Patent number: 6912919
    Abstract: A restriction flowmeter including a cylinder through whose interior a fluid to be measured flows and a pipe for forming a restriction structure penetrating the cylinder in a direction perpendicular to the central axis of the cylinder, the pipe having a diameter smaller than the inner diameter of the cylinder, characterized in that a first pressure measuring hole is formed on the most restricted cross section perpendicular to the flow direction and a second pressure measuring hole is formed on a wall of the cylinder located upstream which is away from the most restricted cross section by ½ or more of the inner diameter of the cylinder.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: July 5, 2005
    Assignee: Wetmaster Co., Ltd.
    Inventors: Yoshijiro Shiba, Masakazu Saito, Shigehito Yamada
  • Publication number: 20050142701
    Abstract: The average film thickness of an amorphous silicon film formed on a substrate is measured. Then, the amorphous silicon film is irradiated with a laser beam to form a polysilicon film. The grain size distribution of the polysilicon film is measured. An optimum value of energy density of laser beam irradiation is calculated on the basis of grain size values measured at two points A and B of the polysilicon film. Then, the average film thickness of a next amorphous silicon film is measured. A value of energy density of laser beam irradiation is calculated on the basis of the average film thickness of the next amorphous silicon film and the average film thickness of the previous amorphous silicon film. The value of energy density is fed back to a laser beam irradiation system.
    Type: Application
    Filed: July 15, 2004
    Publication date: June 30, 2005
    Inventors: Hironaru Yamaguchi, Kiyoshi Ogata, Takuo Tamura, Jun Gotoh, Masakazu Saito, Kazuo Takeda
  • Publication number: 20050139830
    Abstract: A surface roughness of a polycrystalline semiconductor film to be formed by a laser annealing method is reduced. A transmittance distribution filter is disposed at the optical system of a laser annealing apparatus. The transmittance distribution filter controls an irradiation light intensity distribution along a scanning direction of a substrate formed with an amorphous silicon semiconductor thin film to have a distribution having an energy part equal to or higher than a fine crystal threshold on a high energy light intensity side and an energy part for melting and combining only a surface layer. This transmittance distribution filter is applied to an excimer laser annealing method, a phase shift stripe method or an SLS method respectively using a general line beam to thereby reduce the height of protrusions on a polycrystalline surface.
    Type: Application
    Filed: July 28, 2004
    Publication date: June 30, 2005
    Inventors: Kazuo Takeda, Takeshi Sato, Masakazu Saito, Jun Gotoh
  • Publication number: 20050051081
    Abstract: The present invention provides a process for producing a polycrystal silicon film which comprises a step of forming a polycrystal silicon film by light irradiation of a silicon film set on a substrate, and a step of selecting substrate samples having an average grain size in a plane of the sample of 500 nm or more. According to the present invention, stable production of a high-performance poly-silicon TFT liquid crystal display becomes possible.
    Type: Application
    Filed: September 17, 2004
    Publication date: March 10, 2005
    Inventors: Kazuo Takeda, Masakazu Saito, Yukio Takasaki, Hironobu Abe, Makoto Ohkura, Yoshinobu Kimura, Takeo Shiba
  • Publication number: 20040232432
    Abstract: The present invention provides a manufacturing method of a high performance active matrix substrate at a high throughput with a less expensive apparatus, and an image display device using the active matrix substrate. On a stage moving in the short axis direction X and long axis direction Y on a rail, a glass substrate is carried, which has an amorphous silicon semiconductor film formed. Polycrystallized and large grain silicon film may be obtained by intensity modulating the pulsed laser beam in a line beam shape by means of a phase shift mask with a periodicity in the long axis direction Y of the laser beam, moving the laser beam randomly in the modulation direction of the amorphous silicon semiconductor film formed on the glass substrate to expose to crystallize the film. The image display device may incorporate an active matrix substrate having active elements such as thin film transistors formed by this silicon film.
    Type: Application
    Filed: November 14, 2003
    Publication date: November 25, 2004
    Inventors: Takeshi Sato, Kazuo Takeda, Masakazu Saito, Jun Goto, Makoto Ohkura
  • Patent number: 6806099
    Abstract: The present invention provides a process for producing a polycrystal silicon film which comprises a step of forming a polycrystal silicon film by light irraditation of a silicon film set on a substrate, and a step of selecting substrate samples having an average grain size in a plane of the sample of 500 nm or more. According to the present invention, stable production of a high-performance poly-silicon TFT liquid crystal display becomes possible.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: October 19, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Takeda, Masakazu Saito, Yukio Takasaki, Hironobu Abe, Makoto Ohkura, Yoshinobu Kimura, Takeo Shiba
  • Publication number: 20040187598
    Abstract: A restriction flowmeter including a cylinder through whose interior a fluid to be measured flows and a pipe for forming a restriction structure penetrating the cylinder in a direction perpendicular to the central axis of the cylinder, the pipe having a diameter smaller than the inner diameter of the cylinder, characterized in that a first pressure measuring hole is formed on the most restricted cross section perpendicular to the flow direction and a second pressure measuring hole is formed on a wall of the cylinder located upstream which is away from the most restricted cross section by ½ or more of the inner diameter of the cylinder.
    Type: Application
    Filed: January 29, 2004
    Publication date: September 30, 2004
    Inventors: Yoshijiro Shiba, Masakazu Saito, Shigehito Yamada
  • Publication number: 20040060504
    Abstract: Improving the laser annealing method which is the process of polycrystallizing amorphous silicon, thereby forming with a high throughput silicon thin film in which the crystal particle diameter is sufficiently large. In a process of crystallization by irradiation of a semiconductor thin film formed on a substrate with pulsed laser light, one produces a semiconductor thin film which comprises having a means to shape laser light into a linear beam and a means to periodically and spatially modulate the intensity of pulsed laser in the direction of the long axis of the linear beam by passing through a phase-shifting stripy pattern perpendicular to the long axis, and collectively forming for each shot a polycrystalline film composed of crystals which have grown in a certain direction over the entire region irradiated with the linear beam. The crystal grain size is ½ of the hillock interval.
    Type: Application
    Filed: June 17, 2003
    Publication date: April 1, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Takeda, Jun Gotou, Masakazu Saito, Makoto Ohkura, Takeshi Satou, Hiroshi Fukuda, Takeo Shiba
  • Publication number: 20030164501
    Abstract: A display device includes a pixel region having a plurality of pixels and a peripheral circuit region disposed at a periphery of the pixel region for driving the pixels. The peripheral circuit region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a first kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the first kind is at least 3 &mgr;m. The pixel region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a second kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the second kind is at least 0.05 &mgr;m.
    Type: Application
    Filed: January 10, 2003
    Publication date: September 4, 2003
    Inventors: Kenkichi Suzuki, Tetsuya Nagata, Michiko Takahashi, Masakazu Saito, Toshio Ogino, Masanobu Miyano
  • Publication number: 20030064571
    Abstract: The present invention provides a process for producing a polycrystal silicon film which comprises a step of forming a polycrystal silicon film by light irradiation of a silicon film set on a substrate, and a step of selecting substrate samples having an average grain size in a plane of the sample of 500 nm or more. According to the present invention, stable production of a high-performance poly-silicon TFT liquid crystal display becomes possible.
    Type: Application
    Filed: January 31, 2002
    Publication date: April 3, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Takeda, Masakazu Saito, Yukio Takasaki, Hironobu Abe, Makoto Ohkura, Yoshinobu Kimura, Takeo Shiba
  • Patent number: 6512247
    Abstract: A display device includes a pixel region having a plurality of pixels and a peripheral circuit region disposed at a periphery of the pixel region for driving the pixels. The peripheral circuit region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a first kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the first kind is at least 3 &mgr;m. The pixel region includes transistors fabricated from polycrystalline semiconductor and having a semiconductor crystalline grain of a second kind in a channel region thereof, wherein a grain size of the semiconductor crystalline grain of the second kind is at least 0.05 &mgr;m.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: January 28, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kenkichi Suzuki, Tetsuya Nagata, Michiko Takahashi, Masakazu Saito, Toshio Ogino, Masanobu Miyano
  • Patent number: 6274888
    Abstract: A semiconductor device has a thin film transistor including an insulating substrate, an island made of a polycrystalline semiconductor material and disposed on the insulating substrate, a conductive layer made of the polycrystalline semiconductor material and at least one of metals and metallic silicides and surrounding the island, a source region and a drain region spaced from the source region, the source region and the drain region being formed in said island, a gate electrode disposed on the island with an insulating film interposed between the island and the gate electrode, the gate facing a spacing between the source region and the drain region.
    Type: Grant
    Filed: January 10, 2000
    Date of Patent: August 14, 2001
    Assignee: Hitachi, LTD
    Inventors: Kenkichi Suzuki, Tetsuya Nagata, Michiko Takahashi, Masakazu Saito, Toshio Ogino, Masanobu Miyano
  • Patent number: 6150657
    Abstract: An energy filter has a plurality of deflection means and is constructed by using the plural deflection means so that an average track of an electron beam is symmetric and the normal line to a symmetric plane is inclined against an incident direction of the electron beam.
    Type: Grant
    Filed: August 25, 1998
    Date of Patent: November 21, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Koji Kimoto, Yoshifumi Taniguchi, Shunroku Taya, Shigeto Isakozawa, Takashi Aoyama, Masakazu Saito, Tomoko Sekiguchi
  • Patent number: 5328702
    Abstract: A method for preparing a solution containing water-soluble minerals comprising the steps of pulverizing and mixing starch or cereal, seed having water-soluble mineral contents and egg shell, adding water to form an aqueous mixture and agitating the same while heating to approximately 80.degree. C. to form a viscous mixture, fermenting the mixture by adding koji to the mixture, and aging the fermented mixture to cause the water-soluble mineral contents in the seed to be dissolved into the aqueous mixture and filtering the resultant fermented and aged mixture to obtain the solution of water-soluble minerals.
    Type: Grant
    Filed: June 2, 1992
    Date of Patent: July 12, 1994
    Assignees: Keiji Takagi, Makoto Hatto, Masakazu Saito
    Inventors: Makoto Hatto, Masakazu Saito