Patents by Inventor Hiroaki Takasu

Hiroaki Takasu 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: 6369409
    Abstract: It is an object to provide a highly precise bleeder resistance circuit having an accurate voltage division ratio and a small temperature coefficient of the resistance value and a highly precise semiconductor device having a small temperature coefficient using such a bleeder resistance circuit, e.g., a semiconductor device such as a voltage detector and a voltage regulator. Such characteristic features that the potential of electric conductors on the thin film resistors and electric conductors under the thin film resistors of a bleeder resistance circuit using thin film resistors is made almost equal to the potential of respective thin film resistors and that, when polysilicon is used in the thin film resistor, the dispersion of the resistance value is controlled and the temperature dependency of the resistance value is made lower by thinning the film thickness of the polysilicon thin film resistor are constituted.
    Type: Grant
    Filed: August 15, 1996
    Date of Patent: April 9, 2002
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Jun Osanai, Kenji Kitamura
  • Patent number: 6320242
    Abstract: In a semiconductor integrated circuit device having laser-trimmable fuses and a trimming position pattern, in order to increase trimming accuracy and reduce the size of the positioning pattern, the fuses and the positioning pattern are formed using the same thin film. The trimming positioning pattern has an abrupt boundary between a high light reflectivity region and a low reflectivity region so that light reflectivity varies abruptly. To further reduce size, the trimming positioning pattern can be formed in pad areas of a integrated circuit chip or placed at intersections between scribe lines in a wafer.
    Type: Grant
    Filed: October 21, 1998
    Date of Patent: November 20, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Noritoshi Ando, Yoshikazu Kojima, Kazunari Sugiura, Michiaki Yazawaw
  • Publication number: 20010041412
    Abstract: The present invention provides a method of manufacturing a semiconductor device having a bleeder resistance circuit in which the resistance value does not fluctuate in response to the stress applied thereto. A thin film resistor of the semiconductor device manufactured by a manufacturing method according to the present invention is constituted of a P-type thin film resistor formed of a P-type semiconductor thin film and an N-type thin film resistor formed of an N-type semiconductor thin film in order to cancel the changes of the resistance values thereof when the stress is applied thereto. In addition, in the process of forming a source/drain of an NMOS transistor, at the same time, a low resistance region in an N-type polycrystalline silicon resistor is formed, while in the process of forming a source/drain of a PMOS transistor, at the same time, a low resistance region in a P-type polycrystalline silicon resistor is formed.
    Type: Application
    Filed: February 7, 2001
    Publication date: November 15, 2001
    Inventor: Hiroaki Takasu
  • Patent number: 6304243
    Abstract: A highly integrated light valve is formed with a composite substrate formed of a quartz substrate and a monocrystalline silicon thin film layer bonded to the quartz substrate, in which an X driving circuit and a Y driving circuit are integrated utilizing very large scale integration processing. Driving electrodes are arranged in a matrix format on the composite substrate for providing signals output from the X driving circuit and the Y driving circuit to respective transistors and display pixel electrodes arranged at each intersection of the driving electrodes in the matrix. A control circuit for supplying timing signals to the X driving circuit and the Y driving circuit and a display data generating circuit for generating display data in order to display an image are also integrated on the composite substrate. A light source element driving circuit for driving a light source element is provided thereon for projecting a displayed image.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: October 16, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Kenichi Kondo, Kunihiro Takahashi, Hiroaki Takasu, Tsuneo Yamazaki, Atsushi Sakurai
  • Patent number: 6204836
    Abstract: A dense display may be provided with an internal defect detection circuit to enhance production yield. A plurality of pixels, each including thin film transistors and liquid crystal cells driven by driving electrodes, are arranged in a matrix form and scanned by a plurality of control signal lines and a plurality of image signal lines. A control signal line driving circuit is formed of shift registers having one bit per signal line, and sample-and-hold circuits. An inspection circuit is provided with plural switching elements, each having a first terminal connected to a respective image signal line, a second terminal connected to an inspection output line and a third terminal receptive of an inspection control input signal for controlling an electrical connection between the first and second terminals. In accordance with this configuration, inspection of individual signal lines may be achieved and the inspection control input signal may be internally or externally generated.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: March 20, 2001
    Assignee: Seiko Instruments INC
    Inventors: Tsuneo Yamazaki, Kunihiro Takahashi, Hiroaki Takasu, Atsushi Sakurai
  • Patent number: 6191476
    Abstract: To provide a semiconductor substrate and a light-valve semiconductor substrate capable of preventing the threshold value of a MOS transistor on a single-crystal silicon device forming layer from increasing and forming a MOS integrated circuit with a high reliability even for a long-time operation. A semiconductor substrate and a light-valve semiconductor substrate comprising a single-crystal silicon thin-film device forming layer 5001 formed above an insulating substrate 5004 through an adhesive layer 5003 and an insulating layer 5002 formed on the single-crystal silicon thin-film device forming layer, wherein a heat conductive layers 5201 and 5202 made of a material with a high heat conductivity are arranged between the single-crystal silicon thin-film device forming layer and the adhesive layer and on the insulating layer.
    Type: Grant
    Filed: May 20, 1997
    Date of Patent: February 20, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Kunihiro Takahashi, Mizuaki Suzuki, Tsuneo Yamazaki, Hiroaki Takasu, Kunio Nakajima, Atsushi Sakurai, Tadao Iwaki, Yoshikazu Kojima, Masaaki Kamiya
  • Patent number: 6187605
    Abstract: A semiconductor substrate is utilized to integrally form a drive circuit and a pixel array to produce a transparent semiconductor device for a light valve. The semiconductor device for a light valve is constructed of a semiconductor substrate composed of a bulk single crystal silicon having an opaque thick portion and a thin transparent portion. A pixel array is formed in the transparent portion. A drive circuit is formed in a top face of the opaque portion. A transparent support substrate is laminated to the top face of the semiconductor substrate for reinforcement. A bulk portion of the semiconductor substrate is removed from a back face thereof by selective etching to provide the transparent portion.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: February 13, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Yoshikazu Kojima, Kunihiro Takahashi, Tsuneo Yamazaki, Tadao Iwaki
  • Patent number: 6067062
    Abstract: A light valve has a composite substrate comprised of an electrically insulating substrate and a semiconductor single crystal thin film formed over the electrically insulating substrate. A pixel array comprising semiconductor switch elements is formed in the semiconductor single crystal thin film. A peripheral circuit having circuit elements is formed in the semiconductor single crystal thin film so that a small-sized, high speed light valve is obtained. X- driver and Y-driver circuits are formed in the semiconductor single crystal thin film and controlled by a control circuit, such as a video signal processing circuit, which receives and processes video signals inputted directly from an external source. The peripheral circuit can be a DRAM sense amplifier for sensing charges stored in each pixel of the pixel array to detect defects in the pixel array.
    Type: Grant
    Filed: August 23, 1991
    Date of Patent: May 23, 2000
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Yoshikazu Kojima, Masaaki Kamiya, Tsuneo Yamazaki, Hiroshi Suzuki, Masaaki Taguchi, Ryuichi Takano, Satoru Yabe
  • Patent number: 6040200
    Abstract: A method of fabricating a light valve device comprises forming a substrate having stacked layers including a light-shielding thin film layer, an insulating film, and a single crystalline semiconductor thin film stacked in this order on a transparent support substrate. A light-shielding layer pattern is formed by selectively etching the stacked layers. Thereafter, a switching element is formed comprised of a transistor having a channel region formed in the single crystalline semiconductor thin film and a main gate electrode covering the channel region. The channel region is provided over the light-shielding pattern layer to prevent light incident from the transparent support substrate from illuminating the channel region to suppress a photo-induced leakage current in the channel region. A transparent electrode is formed and is electrically connected to the switching element.
    Type: Grant
    Filed: April 14, 1997
    Date of Patent: March 21, 2000
    Assignees: Agency of Industrial Science and Technology, Seiko Instruments Inc.
    Inventors: Yutaka Hayashi, Masaaki Kamiya, Yoshikazu Kojima, Hiroaki Takasu
  • Patent number: 5982461
    Abstract: A light valve device has a drive substrate integrated with a drive electrode. A transistor is connected to the drive electrode and a driving circuit energizes the drive electrode through the transistor. An opposed substrate is provided opposed to the drive electrode, and an electrooptical material layer is disposed between the drive substrate and the opposed substrate. The drive substrate has a structure comprising a substrate layer and a semiconductor single crystal thin film layer. The semiconductor single crystal thin film layer is made by thinning a semiconductor single crystal wafer which has been bonded to the substrate layer. The light valve device has a small size and high pixel density and can be formed using miniaturization technology. The light valve can be used for a small size, high resolution video projector and a color matrix display device.
    Type: Grant
    Filed: February 14, 1992
    Date of Patent: November 9, 1999
    Inventors: Yutaka Hayashi, Masaaki Kamiya, Yoshikazu Kojima, Hiroaki Takasu
  • Patent number: 5982002
    Abstract: A miniaturized light valve with a surface area on the order of several centimeters may be successfully formed using a composite substrate and an opposing substrate which has thereon an electrode and which is bonded to the composite substrate at a predetermined gap therefrom. An electro-optical material, such as a liquid crystal compound, is confined within the gap. The composite substrate includes a single crystal layer of a semiconductor material provided on a lower level insulation layer. The single crystal layer is formed with a source region, a drain region, and a channel region of a MOS transistor, and a gate insulation film is provided on the single crystal layer in alignment with the channel region. Further, a gate electrode is provided on the gate insulation film. The composite substrate further includes a pixel electrode on the upper major surface of an insulation layer deposited over the MOS transistor and in contact with the drain region. The single crystal semiconductor thin film is limited to 0.
    Type: Grant
    Filed: January 27, 1993
    Date of Patent: November 9, 1999
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Yoshikazu Kojima, Kunihiro Takahashi
  • Patent number: 5926699
    Abstract: A method of fabricating a semiconductor device comprises the steps of sequentially forming a first gate electrode and an insulating film over a transparent support substrate, forming a through-hole in the insulating film, forming a semiconductor single crystal silicon thin film over the transparent support substrate by epitaxial growth in the through-hole of the insulating film, forming a transistor element having a channel region formed in the semiconductor single crystal silicon thin film, and forming a second gate electrode over and electrically insulated from the channel region of the transistor element.
    Type: Grant
    Filed: June 2, 1998
    Date of Patent: July 20, 1999
    Assignees: Agency of Industrial Science and Technology, Seiko Instruments Inc.
    Inventors: Yutaka Hayashi, Masaaki Kamiya, Yoshikazu Kojima, Hiroaki Takasu
  • Patent number: 5759878
    Abstract: A method of fabricating a semiconductor device comprises the steps of preparing a transparent support substrate, forming a first gate electrode comprising semiconductor single crystal silicon by epitaxial growth on the transparent support substrate, forming an insulating film over the first gate electrode, forming a through-hole in the insulating film to expose a portion of the first gate electrode, laterally and epitaxially growing a semiconductor single crystal silicon thin film over the transparent substrate by epitaxial growth in the through-hole of the insulating film, forming a transistor element having a channel region formed in the semiconductor single crystal silicon thin film, and forming a second gate electrode over and electrically insulated from the channel region.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: June 2, 1998
    Assignees: Agency of Industrial Science and Technology, Seiko Instruments Inc.
    Inventors: Yutaka Hayashi, Masaaki Kamiya, Yoshikazu Kojima, Hiroaki Takasu
  • Patent number: 5728591
    Abstract: A process for manufacturing a light valve device comprises forming a transparent insulating thin film layer on a surface of a semiconductor substrate, and forming a single crystal semiconductor thin film on a surface of the transparent insulating thin film layer. A portion of the single crystal semiconductor thin film is then removed and at least one pixel electrode is formed on the transparent insulating thin film layer at a region where the single crystal semiconductor thin film has been removed. A driving unit is then formed in the single crystal semiconductor thin film. Thereafter, a carrier substrate is laminated using an adhesive on the surface of the semiconductor substrate at a region corresponding to the pixel electrode and the driving unit. The semiconductor substrate is then removed to expose a surface of the transparent insulating thin film layer and through-holes and a metal film are formed on the exposed surface thereof.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: March 17, 1998
    Assignee: Seiko Instruments Inc.
    Inventors: Kunihiro Takahashi, Yoshikazu Kojima, Hiroaki Takasu, Nobuyoshi Matsuyama, Hitoshi Niwa, Tomoyuki Yoshino, Tsuneo Yamazaki
  • Patent number: 5672518
    Abstract: The invention provides a semi-conductor light valve device and a process for fabricating the same. The device comprises a composite substrate having a supporte substrate, a light-shielding thin film formed on said supporte substrate and semiconductive thin film disposed on the light-shielding thin film with interposing an insulating thin film. A switching element made of a transistor and a transparent electrode for driving light valve are formed on the semiconductive thin film, and the switching element and the transparent electrode are connected electrically with each other. The transistor includes a channel region in the semiconductive thin film and a main gate electrode for controlling the conduction in the channel region, and the light-shielding thin film layer is so formed as to cover the channel region on the side opposite to said channel region, so as to prevent effectively a back channel and shut off the incident light.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: September 30, 1997
    Assignees: Agency of Industrial Science and Technology, Seiko Instruments Inc.
    Inventors: Yutaka Hayashi, Masaaki Kamiya, Yoshikazu Kojima, Hiroaki Takasu
  • Patent number: 5637187
    Abstract: A process for forming a light valve device comprises forming a semiconductor single crystal film to form a composite substrate by polishing a semiconductor single crystal substrate after an electric insulating substrate has been bonded thereto; forming a group of pixel electrodes for defining a pixel region and a group of switch elements for selectively energizing the pixel electrodes by integrating a pixel array portion over the composite substrate; forming a liquid crystal aligning means for the pixel region; superposing an opposed substrate over the composite substrate with a gap therebetween; and filling the gap with liquid crystal material.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: June 10, 1997
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Yoshikazu Kojima, Masaaki Kamiya, Tsuneo Yamazaki, Hiroshi Suzuki, Masaaki Taguchi, Ryuichi Takano, Satoru Yabe
  • Patent number: 5633176
    Abstract: A semiconductor substrate is utilized to integrally form a drive circuit and a pixel array to produce a transparent semiconductor device for a light valve comprising a pixel array region and a drive circuit region on a major face of the semiconductor substrate. A stopper film is formed on the major face of the semiconductor substrate at the pixel array region, and a pixel array is formed over the silicon oxide stopper film. A drive circuit is formed on the drive circuit region, and silicon oxide posts are embedded in the major face of the semiconductor substrate at the drive circuit region. A thickness of the semiconductor substrate is then selectively removed from a back face opposite to the major face thereof to reach the stopper film. After the selective removing step, the portion of the semiconductor substrate under the pixel region is completely removed while a portion of the semiconductor substrate under the drive circuit region remains.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: May 27, 1997
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroaki Takasu, Yoshikazu Kojima, Kunihiro Takahashi, Tsuneo Yamazaki, Tadao Iwaki
  • Patent number: 5618739
    Abstract: A process for manufacturing a semiconductor device comprises forming an SOI substrate by depositing an insulating film of silicon dioxide on a surface of a temporary silicon substrate, thermally bonding a semiconductor substrate of single crystal silicon on a surface of the insulating film, and polishing the semiconductor substrate to form a single crystal semiconductor thin film. A semiconductor integrated circuit is then formed in the single crystal semiconductor thin film. Thereafter, a support substrate is fixedly adhered in face-to-face relation to a surface of the semiconductor integrated circuit opposite to the temporary substrate. The temporary substrate is then removed to expose a surface of the insulating film. The exposed surface of the insulating film is then subjected to a treatment including at least forming an electrode.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: April 8, 1997
    Assignee: Seiko Instruments Inc.
    Inventors: Kunihiro Takahashi, Yoshikazu Kojima, Hiroaki Takasu, Nobuyoshi Matsuyama, Hitoshi Niwa, Tomoyuki Yoshino, Tsuneo Yamazaki
  • Patent number: 5602408
    Abstract: A semiconductor device comprises a silicon semiconductor substrate and an insulating film formed on a surface of the silicon semiconductor substrate. One of a surface of the silicon semiconductor substrate or a surface of the insulating film is provided with at least one step portion. A polycrystalline silicon layer is formed uniformly on at least a side surface of the step portion and a top surface of the insulating film. The polycrystalline silicon layer which is formed on the side surface of the step portion comprises a resistance element, and a portion of the polycrystalline silicon layer which is formed on the top surface of the insulating film is doped with an impurity to form a conductive element. By this construction, the area occupied by the load devices on the semiconductor substrate is effectively reduced, thereby increasing the packing density of the semiconductor device.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: February 11, 1997
    Assignee: Seiko Instruments Inc.
    Inventors: Hitomi Watanabe, Hiroaki Takasu
  • Patent number: RE36836
    Abstract: The invention provides a semi-conductor light valve device and a process for fabricating the same. The device comprises a composite substrate having a supporte substrate, a light-shielding thin film formed on said supporte substrate and semiconductive thin film disposed on the light-shielding thin film with interposing an insulating thin film. A switching element made of a transistor and a transparent electrode for driving light valve are formed on the semiconductive thin film, and the switching element and the transparent electrode are connected electrically with each other. The transistor includes a channel region in the semiconductive thin film and a main gate electrode for controlling the conduction in the channel region, and the light-shielding thin film layer is so formed as to cover the channel region on the side opposite to said channel region, so as to prevent effectively a back channel and shut off the incident light.
    Type: Grant
    Filed: August 2, 1995
    Date of Patent: August 29, 2000
    Assignees: Agency of Industrial Science and Technology, Seiko Instruments Inc.
    Inventors: Yutaka Hayashi, Masaaki Kamiya, Yoshikazu Kojima, Hiroaki Takasu