Patents by Inventor Yutaka Takafuji

Yutaka Takafuji 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: 7528446
    Abstract: The present invention provides a semiconductor substrate, which comprises a singlecrystalline Si substrate which includes an active layer having a channel region, a source region, and a drain region, the singlecrystalline Si substrate including at least a part of a device structure not containing a well-structure or a channel stop region; a gate insulating film formed on the singlecrystalline Si substrate; a gate electrode formed on the gate insulating film; a LOCOS oxide film whose thickness is more than a thickness of the gate insulating film, the LOCOS oxide film being formed on the singlecrystalline Si substrate by surrounding the active layer; and an insulating film formed over the gate electrode and the LOCOS oxide film.
    Type: Grant
    Filed: March 23, 2005
    Date of Patent: May 5, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yutaka Takafuji, Yasumori Fukushima, Masao Moriguchi
  • Patent number: 7525530
    Abstract: Each of a gate driver and a source driver periodically receives a clock signal and a start pulse, where the start pulse has a certain width and is shifted as shift data in the gate driver or source driver in synchronism with the clock signal. A logic circuit composed of an NAND gate and an inverter receives the start pulse and the shift data, the shift data being the output that is supplied after a predetermined delay from the last stage with respect to the shift direction. The output of the inverter is used to test scanning circuits. This provides a display device and a scanning circuit testing method, which enable the scanning circuits to be judged both surely and quickly, without increasing the area or complexity of the circuit.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: April 28, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yutaka Takafuji, Katsunori Shirai, Akira Shibazaki
  • Publication number: 20090095956
    Abstract: A semiconductor device of the present invention is arranged in such a manner that a MOS non-single-crystal silicon thin-film transistor including a non-single-crystal silicon thin film made of polycrystalline silicon, a MOS single-crystal silicon thin-film transistor including a single-crystal silicon thin film, and a metal wiring are provided on an insulating substrate. With this arrangement, (i) a semiconductor device in which a non-single-crystal silicon thin film and a single-crystal silicon thin-film device are formed and high-performance systems are integrated, (ii) a method of manufacturing the semiconductor device, and (iii) a single-crystal silicon substrate for forming the single-crystal silicon thin-film device of the semiconductor device are obtained.
    Type: Application
    Filed: September 29, 2008
    Publication date: April 16, 2009
    Inventors: Yutaka TAKAFUJI, Takashi Itoga
  • Patent number: 7508034
    Abstract: A semiconductor device of the present invention is arranged in such a manner that a MOS non-single-crystal silicon thin-film transistor including a non-single-crystal silicon thin film made of polycrystalline silicon, a MOS single-crystal silicon thin-film transistor including a single-crystal silicon thin film, and a metal wiring are provided on an insulating substrate. With this arrangement, (i) a semiconductor device in which a non-single-crystal silicon thin film and a single-crystal silicon thin-film device are formed and high-performance systems are integrated, (ii) a method of manufacturing the semiconductor device, and (iii) a single-crystal silicon substrate for forming the single-crystal silicon thin-film device of the semiconductor device are obtained.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: March 24, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yutaka Takafuji, Takashi Itoga
  • Publication number: 20090045461
    Abstract: A hydrogen (H) exfoliation gettering method is provided for attaching fabricated circuits to receiver substrates. The method comprises: providing a Si substrate; forming a Si active layer overlying the substrate with circuit source/drain (S/D) regions; implanting a p-dopant into the S/D regions; forming gettering regions underling the S/D regions; implanting H in the Si substrate, forming a cleaving plane (peak concentration (Rp) H layer) in the Si substrate about as deep as the gettering regions; bonding the circuit to a receiver substrate; cleaving the Si substrate along the cleaving plane; and binding the implanted H underlying the S/D regions with p-dopant in the gettering regions, as a result of post-bond annealing.
    Type: Application
    Filed: October 30, 2008
    Publication date: February 19, 2009
    Inventors: Steven R. Droes, Yutaka Takafuji
  • Patent number: 7488980
    Abstract: A relaying pad is formed in a predetermined portion in an insulation layer of the single-crystal thin film device, in a region where the single-crystal thin film device is formed. The relaying pad is for providing connection wiring through the insulator substrate. With this configuration it is possible to prevent an increase in an aspect ratio of a contact hole formed in an insulation layer in a region in which a transferred device is formed, the semiconductor device including a substrate on which the transferred device and a deposited device coexist.
    Type: Grant
    Filed: September 15, 2004
    Date of Patent: February 10, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yutaka Takafuji, Takashi Itoga, Yasuyuki Ogawa
  • Publication number: 20090001504
    Abstract: A transistor formed on a monocrystalline Si wafer is temporarily transferred onto a first temporary supporting substrate. The first temporarily supporting substrate is heat-treated at high heat so as to repair crystal defects generated in a transistor channel of the monocrystalline Si wafer when transferring the transistor. The transistor is then made into a chip and transferred onto a TFT substrate. In order to transfer the transistor which has been once separated from the monocrystalline Si wafer, a different method from a stripping method utilizing ion doping is employed.
    Type: Application
    Filed: December 13, 2006
    Publication date: January 1, 2009
    Inventors: Michiko Takei, Kazuhide Tomiyasu, Yasumori Fukushima, Yutaka Takafuji
  • Publication number: 20080318390
    Abstract: A method for fabricating a semiconductor device according to the present invention is a method for fabricating a semiconductor device including a substrate layer including a plurality of first regions each having an active region and a plurality of second regions each being provided between adjacent ones of the first region. The fabrication method includes an isolation insulation film formation step of forming an isolation insulation film in each of the second regions so that a surface of the isolation insulation film becomes at the same height as that of a surface of a gate oxide film covering the active region, a peeling layer formation step of forming a peeling layer by ion-implanting hydrogen into the substrate layer after the isolation insulation film formation step, and a separation step of separating part of the substrate layer along the peeling layer.
    Type: Application
    Filed: August 12, 2008
    Publication date: December 25, 2008
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Yasumori Fukushima, Masao Moriguchi, Yutaka Takafuji
  • Patent number: 7466011
    Abstract: A hydrogen (H) exfoliation gettering method is provided for attaching fabricated circuits to receiver substrates. The method comprises: providing a Si substrate; forming a Si active layer overlying the substrate with circuit source/drain (S/D) regions; implanting a p-dopant into the S/D regions; forming gettering regions underling the S/D regions; implanting H in the Si substrate, forming a cleaving plane (peak concentration (Rp) H layer) in the Si substrate about as deep as the gettering regions; bonding the circuit to a receiver substrate; cleaving the Si substrate along the cleaving plane; and binding the implanted H underlying the S/D regions with p-dopant in the gettering regions, as a result of post-bond annealing.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: December 16, 2008
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: Steven R. Droes, Yutaka Takafuji
  • Patent number: 7436027
    Abstract: In a semiconductor device including a monocrystalline thin film transistor 16a that has been formed on a monocrystalline Si wafer 100 and then is transferred to a insulating substrate 2, LOCOS oxidization is performed with respect to the element-isolation region of the monocrystalline Si wafer 100 so as to create a field oxide film (SiO2 film) 104, and a marker 107 is formed on the field oxide film 104. With this structure, alignment of components may be performed based on a gate electrode 106 upon or after the transfer step.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: October 14, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuyuki Ogawa, Yutaka Takafuji
  • Publication number: 20080248642
    Abstract: A method is provided for removing reentrant stringers in the fabrication of a nanowire transistor (NWT). The method provides a cylindrical nanostructure with an outside surface axis overlying a substrate surface. The nanostructure includes an insulated semiconductor core. A conductive film is conformally deposited overlying the nanostructure, to function as a gate strap or a combination gate and gate strap. A hard mask insulator is deposited overlying the conductive film and selected regions of the hard mask are anisotropically plasma etched. As a result, a conductive film gate electrode is formed substantially surrounding a cylindrical section of nanostructure. Inadvertently, conductive film reentrant stringers may be formed adjacent the nanostructure outside surface axis, made from the conductive film. The method etches, and so removes the conductive film reentrant stringers.
    Type: Application
    Filed: April 4, 2007
    Publication date: October 9, 2008
    Inventors: Mark A. Crowder, Yutaka Takafuji
  • Patent number: 7425475
    Abstract: A method for fabricating a semiconductor device according to the present invention is a method for fabricating a semiconductor device including a substrate layer including a plurality of first regions each having an active region and a plurality of second regions each being provided between adjacent ones of the first region. The fabrication method includes an isolation insulation film formation step of forming an isolation insulation film in each of the second regions so that a surface of the isolation insulation film becomes at the same height as that of a surface of a gate oxide film covering the active region, a peeling layer formation step of forming a peeling layer by ion-implanting hydrogen into the substrate layer after the isolation insulation film formation step, and a separation step of separating part of the substrate layer along the peeling layer.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: September 16, 2008
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasumori Fukushima, Masao Moriguchi, Yutaka Takafuji
  • Publication number: 20080164483
    Abstract: An active matrix substrate includes a glass substrate, a driver portion formed on the glass substrate in a protruding state, a stepped portion formed along a surface of the driver portion and a surface of the glass substrate, an insulating reentrant-angle compensating film formed on a surface of the stepped portion, for compensating for at least a part of a reentrant-angle shape of the stepped portion, and a wiring layer formed along a surface of the reentrant-angle compensating film and connected to the driver portion.
    Type: Application
    Filed: March 9, 2006
    Publication date: July 10, 2008
    Inventors: Kazuhide Tomiyasu, Yutaka Takafuji, Masao Moriguchi
  • Publication number: 20080149928
    Abstract: The present invention provides a production method of a semiconductor device, which can improve characteristics of a semiconductor element including a single crystal semiconductor layer formed by transferring on an insulating substrate. The present invention is a production method of a semiconductor device comprising a single crystal semiconductor layer formed on an insulating substrate, the production method comprising the steps of: implanting a substance for separation into a single crystal semiconductor substrate, thereby forming a separation layer; transferring a part of the single crystal semiconductor substrate, separated at the separation layer, onto the insulating substrate, thereby forming the single crystal semiconductor layer; forming a hydrogen-containing layer on at least one side of the single crystal semiconductor layer; and diffusing hydrogen from the hydrogen-containing layer to the single crystal semiconductor layer.
    Type: Application
    Filed: January 17, 2006
    Publication date: June 26, 2008
    Inventors: Masao Moriguchi, Yutaka Takafuji, Steven Roy Droes
  • Publication number: 20080128807
    Abstract: In fabricating a semiconductor device, an element forming surface formation step of forming a plurality of element forming surfaces of different heights on a semiconductor layer to have different levels, a semiconductor element formation step of forming a plurality of semiconductor elements and, one in each of a corresponding number of regions of the semiconductor layer, each region including an associated one of the plurality of element forming surfaces, a level-difference compensation insulating film formation step of forming a level-difference compensation insulating film on the semiconductor layer to cover the semiconductor elements and have a surface with different levels along the element forming surfaces, a release layer formation step of forming a release layer in the semiconductor layer by ion-implanting a peeling material through the level-difference compensation insulating film into the semiconductor layer, and a separation step of separating part of the semiconductor layer along the release layer
    Type: Application
    Filed: November 15, 2005
    Publication date: June 5, 2008
    Inventors: Yasumori Fukushima, Yutaka Takafuji, Masao Moriguchi
  • Publication number: 20080042120
    Abstract: An integrated circuit device of the present invention includes a substrate on which at least two types of nano wire element are provided. These nano wire elements have functions and materials different from each other. The nano wire elements are constituted by nano wires having sizes differing depending on types of nano wire element. With this, it is possible to dramatically improve a function of the integrated circuit device, as compared with an integrated circuit device including a substrate on which one type of nano wire element is provided.
    Type: Application
    Filed: May 24, 2007
    Publication date: February 21, 2008
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Akihide Shibata, Katsumasa Fujii, Yutaka Takafuji, Hiroshi Iwata
  • Publication number: 20070235734
    Abstract: On an SOI substrate, a hydrogen ion implantation section in which distribution of hydrogen ions peaks in a BOX layer (buried oxide film layer), and a single-crystal silicon thin-film transistor are formed. Then this SOI substrate is bonded with an insulating substrate. Subsequently, the SOI substrate is cleaved at the hydrogen ion implantation section by carrying out heat treatment, so that an unnecessary part of the SOI substrate is removed, Furthermore, the BOX layer remaining on the single-crystal silicon thin-film transistor is removed by etching. With this, it is possible to from a single-crystal silicon thin-film device on an insulating substrate, without using an adhesive. Moreover, it is possible to provide a semiconductor device which has no surface damage and includes a single-crystal silicon thin film which is thin and uniform in thickness.
    Type: Application
    Filed: June 5, 2007
    Publication date: October 11, 2007
    Inventors: Yutaka Takafuji, Takashi Itoga
  • Patent number: 7262464
    Abstract: A semiconductor device includes a substrate with an insulating surface and a single crystal semiconductor layer, which is bonded to the insulating surface of the substrate. The device further includes a first insulating layer, which is provided between the insulating surface of the substrate and the single crystal semiconductor layer, and a second insulating layer, which has been deposited on the entire insulating surface of the substrate except an area in which the first insulating layer is present.
    Type: Grant
    Filed: February 1, 2005
    Date of Patent: August 28, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yutaka Takafuji, Takashi Itoga
  • Patent number: 7253040
    Abstract: An insulating substrate is bonded to a monocrystalline Si substrate that includes a monocrystalline Si thin film transistor and a hydrogen ion implanted portion. After depositing an amorphous Si thin film, the amorphous Si thin film is modified into a polycrystalline Si thin film by irradiation of the excimer laser. In laser irradiation, the irradiation of the laser beam on the monocrystalline Si thin film transistor is blocked either by inserting a mask in part of the optical path of the laser beam, or by irradiating the laser beam before unnecessary portions of the monocrystalline Si substrate is detached. In this way, the irradiation of the laser beam for forming the polycrystalline Si thin film will not damage the monocrystalline Si thin film transistor in a semiconductor device in which the monocrystalline Si thin film transistor, which has been transferred, and the polycrystalline Si thin film transistor, which has been formed on the insulating substrate, are formed on the insulating substrate.
    Type: Grant
    Filed: August 4, 2004
    Date of Patent: August 7, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takashi Itoga, Yutaka Takafuji, Yoshihiro Yamamoto
  • Patent number: 7244990
    Abstract: On an SOI substrate, a hydrogen ion implantation section in which distribution of hydrogen ions peaks in a BOX layer (buried oxide film layer), and a single-crystal silicon thin-film transistor are formed. Then this SOI substrate is bonded with an insulating substrate. Subsequently, the SOI substrate is cleaved at the hydrogen ion implantation section by carrying out heat treatment, so that an unnecessary part of the SOI substrate is removed, Furthermore, the BOX layer remaining on the single-crystal silicon thin-film transistor is removed by etching. With this, it is possible to from a single-crystal silicon thin-film device on an insulating substrate, without using an adhesive. Moreover, it is possible to provide a semiconductor device which has no surface damage and includes a single-crystal silicon thin film which is thin and uniform in thickness.
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: July 17, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yutaka Takafuji, Takashi Itoga