Patents by Inventor Toshihiro Iizuka

Toshihiro Iizuka 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: 7943475
    Abstract: There is provided a semiconductor device comprising a dielectric film made of a high dielectric constant material, in which a leak current is reduced in the film and which exhibits improved device reliability. Specifically, a dielectric film 142 is a metal-compound film having a composition represented by the formula MOxCyNz wherein x, y and z meet the conditions: 0<x, 0.1?y?1.25, 0.01?z and x+y+z=2; and M comprises at least Hf or Zr.
    Type: Grant
    Filed: January 4, 2006
    Date of Patent: May 17, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Tomoe Yamamoto, Toshihiro Iizuka
  • Publication number: 20100327366
    Abstract: A first adjusting metal, capable of varying the threshold voltage of a first-conductivity-type transistor of a complementary transistor, is added to the first-conductivity-type transistor and a second-conductivity-type transistor at the same time, and a diffusion suppressive element, capable of suppressing diffusion of the first adjusting metal, is added from above a metal gate electrode of the second-conductivity-type transistor.
    Type: Application
    Filed: June 21, 2010
    Publication date: December 30, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Kenzo MANABE, Toshihiro IIZUKA, Daisuke IKENO
  • Publication number: 20100176456
    Abstract: A semiconductor device includes a semiconductor substrate including a P-type semiconductor region, and an N channel MOSFET formed in the P-type semiconductor region, the N channel MOSFET including an insulating film of silicon oxide film or silicon oxynitride film formed on the semiconductor substrate, a gate insulating film including hafnium and formed on the insulating film, a lanthanum oxide film having a film thickness not larger than a predetermined value and formed between the gate insulating film and insulating film, and a gate electrode including a titanium nitride film having a N/Ti atomic ratio less than 1.
    Type: Application
    Filed: January 6, 2010
    Publication date: July 15, 2010
    Inventors: Daisuke Ikeno, Kazuaki Nakajima, Toshihiro Iizuka, Kenzo Manabe, Ichiro Yamamoto
  • Publication number: 20080064147
    Abstract: In a thin film transistor, each of an upper electrode and a lower electrode is formed of at least one material selected from the group consisting of a metal and a metal nitride, represented by TiN, Ti, W, WN, Pt, Ir, Ru. A capacitor dielectric film is formed of at least one material selected from the group consisting of ZrO2, HfO2, (Zrx, Hf1-x)O2 (0<x<1), (Zry, Ti1-y)O2 (0<y<1), (Hfz, Ti1-z)O2 (0<z<1), (Zrk, Til, Hfm)O2 (0<k, l, m<1, k+l+m=1), by an atomic layer deposition process. The thin film transistor thus formed has a minimized leakage current and an increased capacitance.
    Type: Application
    Filed: October 30, 2007
    Publication date: March 13, 2008
    Applicant: NEC CORPORATION
    Inventors: Toshihiro IIZUKA, Tomoe Yamamoto, Mami Toda, Shintaro Yamamichi
  • Publication number: 20070152256
    Abstract: A semiconductor device having a logic section and a memory section that are formed on the same semiconductor chip, including: a first transistor formed in the logic section and having gate electrodes and source and drain regions, and a second transistor formed in the memory section having gate electrodes, source and drain regions and a capacitor, the capacitor being of a MIM structure and having an upper and a lower metal electrode and a capacitor dielectric film sandwiched therebetween, the capacitor dielectric film being formed of a dielectric material which is selected from the group consisting of ZrO2, Hf92, (Zrx, Hf1-x)O2 (0<x<1), (Zry, Ti1-y)o2 (0<y<1), (Hfz, Ti1-z)92 (0<z<1 and (Zrk, Til, Hfm)o2 (0<k, l, m<1, k+l+m?1), wherein each of the first and second transistors has a refractory metal silicide layer formed over each of the source and drain regions thereof and the lower metal electrode is connected through a metal plug to the refractory metal silicide layer formed over one o
    Type: Application
    Filed: December 12, 2006
    Publication date: July 5, 2007
    Inventors: Toshihiro Iizuka, Tomoe Yamamoto, Mami Toda, Shintaro Yamamichi
  • Publication number: 20060121671
    Abstract: There is provided a semiconductor device comprising a dielectric film made of a high dielectric constant material, in which a leak current is reduced in the film and which exhibits improved device reliability. Specifically, a dielectric film 142 is a metal-compound film having a composition represented by the formula MOxCyNz wherein x, y and z meet the conditions: 0<x, 0.1?y?1.25, 0.01?z and x+y+z=2; and M comprises at least Hf or Zr.
    Type: Application
    Filed: January 4, 2006
    Publication date: June 8, 2006
    Applicant: NEC ELECTRONICS CORPORATION
    Inventors: Tomoe Yamamoto, Toshihiro Iizuka
  • Patent number: 6875667
    Abstract: A capacitor is provided that is optimal for use in DRAM and has high dielectric constant, and allows leakage current flowing therethrough to be maintained at a low level, and further, permits dependence of the leakage current on temperatures to be small. That is, capacitor openings are formed in an inter layer silicon oxide layer and a TiN film is patterned so that TiN films are left only within the openings to form lower electrodes within the openings. Subsequently, a Zr- and/or Hf-containing oxide film (represented by the formula, multicomponent Zr.sub.x.Hf.sub.1-x.O.sub.2 film (0?x?1)) formed from a metal-containing organic compound as a reactant and a Ti-containing oxide film are laminated to form capacitor dielectrics.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: April 5, 2005
    Assignee: NEC Electronics Corporation
    Inventors: Toshihiro Iizuka, Tomoe Yamamoto
  • Publication number: 20050051824
    Abstract: In a thin film transistor, each of an upper electrode and a lower electrode is formed of at least one material selected from the group consisting of a metal and a metal nitride, represented by TiN, Ti, W, WN, Pt, Ir, Ru. A capacitor dielectric film is formed of at least one material selected from the group consisting of ZrO2, HfO2, (Zrx, Hf1-x)O2 (0<x<1), (Zry, Ti1-y)O2 (0<y<1), (Hfz, Ti1-z)O2 (O<z<l), (Zrk, Til, Hfm)O2 (0<k, l, m<1, k+l+m=1), by an atomic layer deposition process. The thin film transistor thus formed has a minimized leakage current and an increased capacitance.
    Type: Application
    Filed: October 18, 2004
    Publication date: March 10, 2005
    Inventors: Toshihiro Iizuka, Tomoe Yamamoto, Mami Toda, Shintaro Yamamichi
  • Publication number: 20040217478
    Abstract: There is provided a semiconductor device comprising a dielectric film made of a high dielectric constant material, in which a leak current is reduced in the film and which exhibits improved device reliability. Specifically, a dielectric film 142 is a metal-compound film having a composition represented by the formula MOxCyNz wherein x, y and z meet the conditions: 0<x, 0.1≦y≦1.25, 0.01≦z and x+y+z=2; and M comprises at least Hf or Zr.
    Type: Application
    Filed: March 24, 2004
    Publication date: November 4, 2004
    Inventors: Tomoe Yamamoto, Toshihiro Iizuka
  • Publication number: 20040072401
    Abstract: A capacitor is provided that is optimal for use in DRAM and has high dielectric constant, and allows leakage current flowing therethrough to be maintained at a low level, andfurther, permits dependence of the leakage current on temperatures to besmall. Thatis, capacitor openings are formed in an inter layer silicon oxide layer and a TiN film is patterned so that TiN films are left only within the openings to form lower electrodes within the openings. Subsequently, a Zr- and/or Hf-containing oxide film (represented by the formula, multicomponent Zr.sub.x.Hf.sub.1-x.O.sub.2 film (0≦x≦1)) formed from a metal-containing organic compound as a reactant and a Ti-containing oxide film are laminated to form capacitor dielectrics.
    Type: Application
    Filed: October 8, 2003
    Publication date: April 15, 2004
    Applicant: NEC Electronics Corporation
    Inventors: Toshihiro Iizuka, Tomoe Yamamoto
  • Patent number: 6602722
    Abstract: A barium strontium titanate is the ferroelectric substance with the perovskite structure available for a capacitor as a dielectric layer, and is crystallized through a high temperature heat treatment, in which the barium strontium titanate is further subjected to a low temperature heat treatment under the crystallizing temperature of the barium strontium titanate for eliminating impurities such as carbon and hydrogen therefrom so that the leakage current is drastically reduced.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: August 5, 2003
    Assignee: NEC Corporation
    Inventors: Ichiro Yamamoto, Toshihiro Iizuka, Yoshitake Kato
  • Patent number: 6596602
    Abstract: The method for fabricating a semiconductor device in accordance with the present invention has the steps of: forming a metal film as a lower electrode of a capacitor on a semiconductor substrate, followed by forming a capacity insulator film over the lower electrode by the ALCVD process; and forming an upper electrode of the capacitor on the capacity insulator film.
    Type: Grant
    Filed: January 24, 2002
    Date of Patent: July 22, 2003
    Assignee: NEC Corporation
    Inventors: Toshihiro Iizuka, Tomoe Yamamoto
  • Publication number: 20020190294
    Abstract: In a thin film transistor, each of an upper electrode and a lower electrode is formed of at least one material selected from the group consisting of a metal and a metal nitride, represented by TiN, Ti, W, WN, Pt, Ir, Ru. A capacitor dielectric film is formed of at least one material selected from the group consisting of ZrO2, HfO2, (Zrx, Hf1−x)O2 (0<x<1), (Zry, Ti1−y)O2 (0<y<1), (Hfz, Ti1−z)O2 (0<z<1), (Zrk, Til, Hfm)O2 (0<k, l, m<1, k+l+m=1), by an atomic layer deposition process. The thin film transistor thus formed has a minimized leakage current and an increased capacitance.
    Type: Application
    Filed: June 13, 2002
    Publication date: December 19, 2002
    Inventors: Toshihiro Iizuka, Tomeo Yamamoto, Mami Toda, Shintaro Yamamichi
  • Patent number: 6448597
    Abstract: A DRAM includes a MOSFET and a stacked capacitor in each memory cell. The stacked capacitor includes a bottom electrode substantially of a cylindrical shape, a top electrode received in the cylindrical-shape bottom electrode, and a capacitor dielectric film for insulation therebetween. The cylindrical shape of the bottom electrode allows a larger deviation for alignment between the capacitor and the capacitor contact.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: September 10, 2002
    Assignee: NEC Corporation
    Inventors: Naoki Kasai, Toshihiro Iizuka
  • Publication number: 20020119617
    Abstract: A barium strontium titanate is the ferroelectric substance with the perovskite structure available for a capacitor as a dielectric layer, and is crystallized through a high temperature heat treatment, in which the barium strontium titanate is further subjected to a low temperature heat treatment under the crystallizing temperature of the barium strontium titanate for eliminating impurities such as carbon and hydrogen therefrom so that the leakage current is drastically reduced.
    Type: Application
    Filed: April 30, 2002
    Publication date: August 29, 2002
    Applicant: NEC Corporation
    Inventors: Ichiro Yamamoto, Toshihiro Iizuka, Yoshitake Kato
  • Publication number: 20020102810
    Abstract: The method for fabricating a semiconductor device in accordance with the present invention has the steps of: forming a metal film as a lower electrode of a capacitor on a semiconductor substrate, followed by forming a capacity insulator film over the lower electrode by the ALCVD process; and forming an upper electrode of the capacitor on the capacity insulator film.
    Type: Application
    Filed: January 24, 2002
    Publication date: August 1, 2002
    Applicant: NEC CORPORATION
    Inventors: Toshihiro Iizuka, Tomoe Yamamoto
  • Patent number: 6349019
    Abstract: This invention provides a magnetic head device to be incorporated in a hard disc drive device which can minimize the fluctuations in the height of a floating head slider between the outer periphery and inner periphery of a magnetic disc and which has stable floating characteristics over the whole recording area thereof. The magnetic head device includes a head arm which is attached within a hard disc drive device in a rotatable/swingable manner and a head slider fixed on an end of a suspension member extending from the head arm, wherein the distance between the rotational center of the head arm to the center of the head slider and the position of the center of the rotation of the head arm are so determined to satisfy the relation, −0.1≦(D−L)≦0.6 W−4.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: February 19, 2002
    Assignee: TDK Corporation
    Inventors: Toshihiro Iizuka, Yukihito Ito, Shoji Toyoda
  • Publication number: 20020019109
    Abstract: In a semiconductor memory device production method for a semiconductor memory device having a capacitor formed by a high dielectric insulation film and a noble metal upper electrode successively formed on a noble metal lower electrode, the formation of the capacitor is followed by anneal in a gas mixture atmosphere of oxygen concentration of 0 to 5% and nitrogen at temperature of 300 to 400 degrees C. This enables to reduce the leak current at room temperature and suppress leak current increase during a high temperature operation.
    Type: Application
    Filed: October 16, 2001
    Publication date: February 14, 2002
    Applicant: NEC CORPORATION
    Inventor: Toshihiro Iizuka
  • Patent number: 6338996
    Abstract: In a semiconductor memory device production method for a semiconductor memory device having a capacitor formed by a high dielectric insulation film and a noble metal upper electrode successively formed on a noble metal lower electrode, the formation of the capacitor is followed by anneal in a gas mixture atmosphere of oxygen concentration of 0 to 5% and nitrogen at temperature of 300 to 400 degrees C. This enables to reduce the leak current at room temperature and suppress leak current increase during a high temperature operation.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: January 15, 2002
    Assignee: NEC Corporation
    Inventor: Toshihiro Iizuka
  • Patent number: 6326258
    Abstract: A method of manufacturing a semiconductor device such as a semiconductor memory device having a thin film capacitor. The thin film capacitor is formed by sequentially stacking a lower electrode of noble metal, a high dielectric constant insulating film and an upper electrode of noble metal. After forming said capacitor, a first annealing process is performed in an atmosphere including hydrogen and, thereafter, a second annealing process is performed in an atmosphere which does not include hydrogen at a temperature equal to or lower than a temperature of said first annealing process. The first annealing process is performed, for example, in a mixed gas including hydrogen and nitrogen. The second annealing process is performed, for example, in an atmosphere including at least one selected from a group consisting of nitrogen gas, inert gas and oxygen gas.
    Type: Grant
    Filed: April 20, 2000
    Date of Patent: December 4, 2001
    Assignee: NEC Corporation
    Inventor: Toshihiro Iizuka