Patents by Inventor Takahiro Korenari

Takahiro Korenari 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: 8334553
    Abstract: A thin-film transistor manufactured on a transparent substrate has a structure of a top gate type crystalline silicon thin-film transistor in which a light blocking film, a base layer, a crystalline silicon film, a gate insulating film, and a gate electrode film arranged not to overlap at least a channel region are sequentially formed on the transparent substrate. The channel region has channel length L, LDD regions having LDD length d on both sides of the channel region, a source region, and a drain region are formed in the crystalline silicon film. The light blocking film is divided across the channel region. Interval x between the divided light blocking films is equal to or larger than channel length L and equal to or smaller than a sum of channel length L and a double of LDD length d (L+2d), allowing low the manufacturing cost and suppressed photo leak current.
    Type: Grant
    Filed: February 14, 2011
    Date of Patent: December 18, 2012
    Assignee: NLT Technologies, Ltd.
    Inventors: Shigeru Mori, Takahiro Korenari, Hiroshi Tanabe
  • Patent number: 8242553
    Abstract: A thin film transistor (TFT) substrate includes first and second TFTs on the same substrate. The first TFT has a feature that a lower conductive layer or a bottom gate electrode layer is provided between the substrate and a first insulating layer while an upper conductive layer or a top gate electrode layer is disposed on a second insulating layer formed on a semiconductor layer which is formed on the first insulating layer. The first conductive layer has first and second areas such that the first area overlaps with the first conductive layer without overlapping with the semiconductor layer while the second area overlaps with the semiconductor layer, and the first area is larger than the second area while the second insulating layer is thinner than the first insulating layer. The second TFT has the same configuration as the first TFT except that the gate electrode layer is eliminated.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: August 14, 2012
    Assignee: NLT Technologies, Ltd.
    Inventors: Takahiro Korenari, Hiroshi Tanabe
  • Publication number: 20110198607
    Abstract: A thin-film transistor manufactured on a transparent substrate has a structure of a top gate type crystalline silicon thin-film transistor in which a light blocking film, a base layer, a crystalline silicon film, a gate insulating film, and a gate electrode film arranged not to overlap at least a channel region are sequentially formed on the transparent substrate. The channel region has channel length L, LDD regions having LDD length d on both sides of the channel region, a source region, and a drain region are formed in the crystalline silicon film. The light blocking film is divided across the channel region. Interval x between the divided light blocking films is equal to or larger than channel length L and equal to or smaller than a sum of channel length L and a double of LDD length d (L+2d), allowing low the manufacturing cost and suppressed photo leak current.
    Type: Application
    Filed: February 14, 2011
    Publication date: August 18, 2011
    Applicant: NEC LCD TECHNOLOGIES, LTD.
    Inventors: Shigeru MORI, Takahiro KORENARI, Hiroshi TANABE
  • Patent number: 7981811
    Abstract: A base layer is formed on an insulating substrate, and a semiconductor layer is formed in localized fashion thereon. A gate insulating film is then formed so as to cover the semiconductor layer, and a gate electrode is formed on a portion of the gate insulating film. An impurity is then implanted into the semiconductor layer via the gate insulating film, and a source region, a drain region, and an LDD region are formed. The gate insulating film is etched with dilute hydrofluoric acid. An electrode-protecting insulating film is then formed so as to cover the gate electrode, and the entire surface of the surface layer portion of the electrode-protecting insulating film is etched away using dilute hydrofluoric acid. Carrier traps introduced into the electrode-protecting insulating film and the gate insulating film are thereby removed.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: July 19, 2011
    Assignees: NEC Corporation, NEC LCD Technologies, Ltd
    Inventors: Shigeru Mori, Takahiro Korenari, Tadahiro Matsuzaki, Hiroshi Tanabe
  • Publication number: 20110024755
    Abstract: A thin film transistor (TFT) substrate includes first and second TFTs on the same substrate. The first TFT has a feature that a lower conductive layer or a bottom gate electrode layer is provided between the substrate and a first insulating layer while an upper conductive layer or a top gate electrode layer is disposed on a second insulating layer formed on a semiconductor layer which is formed on the first insulating layer. The first conductive layer has first and second areas such that the first area overlaps with the first conductive layer without overlapping with the semiconductor layer while the second area overlaps with the semiconductor layer, and the first area is larger than the second area while the second insulating layer is thinner than the first insulating layer. The second TFT has the same configuration as the first TFT except that the gate electrode layer is eliminated.
    Type: Application
    Filed: July 19, 2010
    Publication date: February 3, 2011
    Applicant: NEC LCD TECHNOLOGIES, LTD.
    Inventors: Takahiro KORENARI, Hiroshi TANABE
  • Patent number: 7633571
    Abstract: Recognizing the phenomenon that the film thickness of a semiconductor layer causes shift in the OFF-leak current characteristic that corresponds to back-gate voltage of a thin-film transistor, the average film thickness of a semiconductor layer is prescribed such that the shift of the OFF-leak current characteristic is reduced. Alternatively, the film thickness distribution (the ratio of the occurrence of each region having different film thickness) in the direction of the channel width of the semiconductor layer is prescribed.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: December 15, 2009
    Assignee: NEC Corporation
    Inventors: Takahiro Korenari, Hiroshi Tanabe, Nobuya Seko
  • Publication number: 20090295699
    Abstract: Off-leak current of a TFT, required for a drive circuit configured with a TFT of a single conductivity type, is realized with simple manufacturing steps. The impurity concentration of a source region and a drain region of a TFT is set between 2*1018 cm?3 and 2*1019 cm?3, whereby off-leak current of the TFT can be sufficiently reduced even in a single gate structure.
    Type: Application
    Filed: May 21, 2009
    Publication date: December 3, 2009
    Applicant: NEC LCD Technologies, Ltd.
    Inventors: Takahiro Korenari, Kunihiro Shiota, Soichi Saito
  • Publication number: 20090286374
    Abstract: A base layer is formed on an insulating substrate, and a semiconductor layer is formed in localized fashion thereon. A gate insulating film is then formed so as to cover the semiconductor layer, and a gate electrode is formed on a portion of the gate insulating film. An impurity is then implanted into the semiconductor layer via the gate insulating film, and a source region, a drain region, and an LDD region are formed. The gate insulating film is etched with dilute hydrofluoric acid. An electrode-protecting insulating film is then formed so as to cover the gate electrode, and the entire surface of the surface layer portion of the electrode-protecting insulating film is etched away using dilute hydrofluoric acid. Carrier traps introduced into the electrode-protecting insulating film and the gate insulating film are thereby removed.
    Type: Application
    Filed: July 24, 2009
    Publication date: November 19, 2009
    Applicants: NEC CORPORATION, NEC LCD TECHNOLOGIES, LTD
    Inventors: Shigeru MORI, Takahiro KORENARI, Tadahiro MATSUZAKI, Hiroshi TANABE
  • Patent number: 7582933
    Abstract: A base layer is formed on an insulating substrate, and a semiconductor layer is formed in localized fashion thereon. A gate insulating film is then formed so as to cover the semiconductor layer, and a gate electrode is formed on a portion of the gate insulating film. An impurity is then implanted into the semiconductor layer via the gate insulating film, and a source region, a drain region, and an LDD region are formed. The gate insulating film is etched with dilute hydrofluoric acid. An electrode-protecting insulating film is then formed so as to cover the gate electrode, and the entire surface of the surface layer portion of the electrode-protecting insulating film is etched away using dilute hydrofluoric acid. Carrier traps introduced into the electrode-protecting insulating film and the gate insulating film are thereby removed.
    Type: Grant
    Filed: July 11, 2006
    Date of Patent: September 1, 2009
    Assignees: NEC Corporation, NEC LCD Technologies, Ltd
    Inventors: Shigeru Mori, Takahiro Korenari, Tadahiro Matsuzaki, Hiroshi Tanabe
  • Patent number: 7294881
    Abstract: At least either above or below a memory transistor formed on an insulating substrate, a shielding layer which has an area larger than that of the semiconductor layer of the memory transistor and has either an electromagnetic wave shielding effect or a light shielding effect or both of these is provided, and by this shielding layer, electromagnetic waves or light is prevented from entering the semiconductor layer. Or, the regional area of at least one of the gate and the charge accumulation layer of the memory transistor is made larger than the semiconductor layer to prevent electromagnetic waves or light from entering the semiconductor layer by the gate or the charge accumulation layer.
    Type: Grant
    Filed: February 2, 2005
    Date of Patent: November 13, 2007
    Assignee: NEC Corporation
    Inventors: Takahiro Korenari, Kenji Sera, Hiroshi Kanou
  • Patent number: 7173593
    Abstract: A liquid crystal display includes pixels arrayed in a matrix of rows and columns, scanning lines extending along the rows of the pixels, signal lines extending along the columns of the pixels, and pixel driving sections which are disposed near intersections of the scanning lines and signal lines, and each of which is controlled via one scanning line to capture a data signal on one signal line and output the data signal to one pixel. Particularly, each pixel driving section includes a memory circuit having a transistor whose gate is connected to the one signal line, and first and second storage capacitances which are charged to positive and negative power supply voltages and connected to a source and drain of the transistor to store the data signal as analog drive voltages of positive and negative polarities, respectively.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: February 6, 2007
    Assignee: Advanced LCD Technologies Development Center Co., Ltd.
    Inventors: Masakiyo Matsumura, Takahiro Korenari
  • Publication number: 20070012924
    Abstract: A base layer is formed on an insulating substrate, and a semiconductor layer is formed in localized fashion thereon. A gate insulating film is then formed so as to cover the semiconductor layer, and a gate electrode is formed on a portion of the gate insulating film. An impurity is then implanted into the semiconductor layer via the gate insulating film, and a source region, a drain region, and an LDD region are formed. The gate insulating film is etched with dilute hydrofluoric acid. An electrode-protecting insulating film is then formed so as to cover the gate electrode, and the entire surface of the surface layer portion of the electrode-protecting insulating film is etched away using dilute hydrofluoric acid. Carrier traps introduced into the electrode-protecting insulating film and the gate insulating film are thereby removed.
    Type: Application
    Filed: July 11, 2006
    Publication date: January 18, 2007
    Inventors: Shigeru Mori, Takahiro Korenari, Tadahiro Matsuzaki, Hiroshi Tanabe
  • Publication number: 20060109225
    Abstract: A device excellent in electrical characteristics is provided by suppressing an operation failure owing to a hysteresis effect that occurs in a circuit using MOS transistors having floating bodies. Moreover, sensitivity of a sense amplifier circuit and a latch circuit including these MOS transistors as components is improved. A signal required in a circuit other than a first circuit is outputted by using electrical characteristics of MOS transistors in a first period (effective period), and in a second period (idle period) excluding the first period, between the gate and source of MOS transistors, a step waveform voltage not less than threshold voltages of these MOS transistors is given.
    Type: Application
    Filed: September 19, 2005
    Publication date: May 25, 2006
    Inventors: Hiroshi Haga, Tomohiko Otose, Hideki Asada, Yoshihiro Nonaka, Takahiro Korenari, Kenichi Takatori
  • Patent number: 6963173
    Abstract: An organic light emitting diode element and an EL drive transistor are arranged in each of a plurality of pixel areas defined by two adjacent scanning signal wirings and neighboring video signal wiring and current supply wiring. A current supplied to the organic light emitting diode element connected to a drain area of the drive transistor is controlled by a voltage between a gate electrode and a source electrode of the EL drive transistor, and a body electrode provided to the EL drive transistor as a fourth electrode is earthed in such a manner that excessive carriers generated in a channel area are caused to escape from the drive transistor through the body electrode.
    Type: Grant
    Filed: May 17, 2004
    Date of Patent: November 8, 2005
    Assignee: Advanced LCD Technologies Development Center Co., Ltd.
    Inventors: Genshiro Kawachi, Takahiro Korenari
  • Publication number: 20050212987
    Abstract: Recognizing the phenomenon that the film thickness of a semiconductor layer causes shift in the OFF-leak current characteristic that corresponds to back-gate voltage of a thin-film transistor, the average film thickness of a semiconductor layer is prescribed such that the shift of the OFF-leak current characteristic is reduced. Alternatively, the film thickness distribution (the ratio of the occurrence of each region having different film thickness) in the direction of the channel width of the semiconductor layer is prescribed.
    Type: Application
    Filed: January 6, 2005
    Publication date: September 29, 2005
    Inventors: Takahiro Korenari, Hiroshi Tanabe, Nobuya Seko
  • Publication number: 20050184407
    Abstract: A TFT circuit includes a source terminal, a drain terminal, and first and second transistors having source-drain paths that are connected in series between the source terminal and the drain terminal, and mutually independent gate electrodes. The TFT circuit further includes upper and lower shaping circuits that, at least, turn off all of the first and second transistors by differentiating gate potentials such that a voltage between the source terminal and the drain terminal may substantially equally be distributed to the first and second transistors.
    Type: Application
    Filed: February 17, 2005
    Publication date: August 25, 2005
    Inventor: Takahiro Korenari
  • Publication number: 20050167668
    Abstract: At least either above or below a memory transistor formed on an insulating substrate, a shielding layer which has an area larger than that of the semiconductor layer of the memory transistor and has either an electromagnetic wave shielding effect or a light shielding effect or both of these is provided, and by this shielding layer, electromagnetic waves or light is prevented from entering the semiconductor layer. Or, the regional area of at least one of the gate and the charge accumulation layer of the memory transistor is made larger than the semiconductor layer to prevent electromagnetic waves or light from entering the semiconductor layer by the gate or the charge accumulation layer.
    Type: Application
    Filed: February 2, 2005
    Publication date: August 4, 2005
    Applicant: NEC CORPORATION
    Inventors: Takahiro Korenari, Kenji Sera, Hiroshi Kanou
  • Publication number: 20040233147
    Abstract: An organic light emitting diode element and an EL drive transistor are arranged in each of a plurality of pixel areas defined by two adjacent scanning signal wirings and neighboring video signal wiring and current supply wiring. A current supplied to the organic light emitting diode element connected to a drain area of the drive transistor is controlled by a voltage between a gate electrode and a source electrode of the EL drive transistor, and a body electrode provided to the EL drive transistor as a fourth electrode is earthed in such a manner that excessive carriers generated in a channel area are caused to escape from the drive transistor through the body electrode.
    Type: Application
    Filed: May 17, 2004
    Publication date: November 25, 2004
    Inventors: Genshiro Kawachi, Takahiro Korenari
  • Patent number: 6753549
    Abstract: A thin film transistor capable of controlling the dispersion in its characteristic, which includes a glass base plate 2, an insulating foundation film 3 made of silicon dioxide (SiO2) and formed on the glass base plate 2, a semiconductor layer 4 made of silicon (Si) formed on the insulating foundation film 3, a source region 8 and a drain region 9 which are formed on the semiconductor layer 4 to be separately located on both sides in the longitudinal direction of the semiconductor layer, a channel region 10 existing between the source region 8 and drain region 9, a gate insulating film 6 made of SiO2 and formed on the channel region 10, and a gate electrode 7 formed on the gate insulating film 6, wherein the taper angle &thgr; of the end portion 5 located in the width direction WD of the channel region 10 covered by at least the gate electrode 7 is 60° or more.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: June 22, 2004
    Assignee: Kabushiki Kaisha Ekisho Sentan Gijutsu Kaihatsu Center
    Inventor: Takahiro Korenari
  • Publication number: 20040070560
    Abstract: A liquid crystal display includes pixels arrayed in a matrix of rows and columns, scanning lines extending along the rows of the pixels, signal lines extending along the columns of the pixels, and pixel driving sections which are disposed near intersections of the scanning lines and signal lines, and each of which is controlled via one scanning line to capture a data signal on one signal line and output the data signal to one pixel. Particularly, each pixel driving section includes a memory circuit having a transistor whose gate is connected to the one signal line, and first and second storage capacitances which are charged to positive and negative power supply voltages and connected to a source and drain of the transistor to store the data signal as analog drive voltages of positive and negative polarities, respectively.
    Type: Application
    Filed: September 16, 2003
    Publication date: April 15, 2004
    Inventors: Masakiyo Matsumura, Takahiro Korenari