Patents by Inventor Katsunori Yahashi

Katsunori Yahashi 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: 20090283819
    Abstract: A nonvolatile semiconductor memory device includes: a substrate; a plurality of dielectric films and electrode films which are alternately stacked on the substrate and have a through hole penetrating in the stacking direction; a semiconductor pillar formed inside the through hole; and a charge storage layer provided at least between the semiconductor pillar and the electrode film. At least part of a side surface of a portion of the through hole located in the electrode film is sloped relative to the stacking direction.
    Type: Application
    Filed: March 20, 2009
    Publication date: November 19, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masao Ishikawa, Katsunori Yahashi
  • Publication number: 20090256178
    Abstract: A semiconductor device includes a dielectric film and gate electrode that are stacked on a substrate, sidewalls formed to cover the side surfaces of the electrode and dielectric film, and SiGe films formed to sandwich the sidewalls, electrode and dielectric film, filled in portions separated from the sidewalls, having upper portions higher than the surface of the substrate and having silicide layers formed on regions of exposed from the substrate. The lower portion of the SiGe film that faces the electrode is formed to extend in a direction perpendicular to the surface of the substrate and the upper portion is inclined and separated farther apart from the gate electrode as the upper portion is separated away from the surface of the substrate. The surface of the silicide layer of the SiGe film that faces the gate electrode is higher than the channel region.
    Type: Application
    Filed: March 23, 2009
    Publication date: October 15, 2009
    Inventors: Kouji MATSUO, Katsunori Yahashi, Takashi Shinyama
  • Publication number: 20090221147
    Abstract: A method of fabricating a semiconductor device according to an embodiment includes: forming a core material on a workpiece material; forming a cover film to cover the upper and side surfaces of the core material; after forming the cover film, removing the core material; after removing the core material, removing the cover film while leaving portions thereof located on the side surfaces of the core material, so as to form sidewall spacer masks; and etching the workpiece material by using the sidewall spacer masks as a mask.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 3, 2009
    Inventors: Keisuke Kikutani, Katsunori Yahashi
  • Publication number: 20090212337
    Abstract: A hard mask material film is formed on a semiconductor substrate and a recess is formed immediately below an opening in an upper surface of the semiconductor substrate. Next, a p-type region is formed immediately below the recess by implanting impurities into an imaging region using the hard mask material film as a mask. Moreover, a trench is formed by further processing the recess in a processing region. A half-buried dielectric film and a STI are formed by burying a dielectric material in the recess and the trench to remove the hard mask material film. Next, two electrodes are formed so as to overlap the half-buried dielectric film and the STI, respectively, and impurities are implanted into the imaging region using one electrode and the half-buried dielectric film as a mask, and hence a n-type region constituting a photodiode is formed in a region being in contact with the p-type region in the semiconductor substrate.
    Type: Application
    Filed: February 19, 2009
    Publication date: August 27, 2009
    Inventors: Atsushi MURAKOSHI, Katsunori Yahashi
  • Publication number: 20090130851
    Abstract: A method for manufacturing a semiconductor device, comprises forming a first film above a pattern forming material, patterning the first film to form a core material pattern, forming a second film above the pattern forming material so as to cover a side surface and an upper surface of the core material pattern, forming a third film above the second film as a protective material for the second film, etching the second and third films so that side wall sections including the second film and the third film are formed on both sides of the core material pattern and the second film and the third film of an area other than the side wall sections are removed, removing the core material pattern between the side wall sections, and transferring patterns corresponding to the side wall sections on the pattern forming material by using the side wall sections as a mask.
    Type: Application
    Filed: November 19, 2008
    Publication date: May 21, 2009
    Inventors: Makoto Hasegawa, Katsunori Yahashi, Shuichi Taniguchi
  • Publication number: 20090096007
    Abstract: A semiconductor memory device comprises a plurality of transistors having a stacked-gate structure. Each transistor includes a semiconductor substrate, a gate insulator formed on the semiconductor substrate, a lower gate formed on the semiconductor substrate with the gate insulator interposed, an intergate insulator formed on the lower gate, and an upper gate formed and silicided on the lower gate with the intergate insulator interposed. A portion of the transistors has an aperture formed through the intergate insulator to connect the lower gate with the upper gate and further includes a block film composed of an insulator and formed smaller than the upper gate and larger than the aperture above the upper gate to cover the aperture.
    Type: Application
    Filed: October 2, 2008
    Publication date: April 16, 2009
    Inventors: Mitsuhiro OMURA, Satoshi NAGASHIMA, Katsunori YAHASHI, Jungo INABA, Daina INOUE
  • Patent number: 7387921
    Abstract: Disclosed is a method of manufacturing a semiconductor device, comprising forming a gate electrode on a main surface of a semiconductor substrate via a gate insulating film, laminating sequentially a first insulating film with oxidation resistance and a silicon film on the main surface of the semiconductor substrate on which the gate electrode is formed, eliminating selectively the silicon film except for a side face of the gate electrode, and oxidizing the silicon film to transform it into a first silicon oxide film, eliminating the first insulating film on the main surface of the semiconductor substrate by using the first silicon oxide film as a mask, and then forming a first impurity layer on the main surface of the semiconductor substrate, laminating a sidewall insulating film thicker than the first silicon oxide film on the side face of the gate electrode on which the first silicon oxide film is formed, and forming a second impurity layer which has the same conduction type as that of the first impurity l
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: June 17, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsunori Yahashi, Keiichi Takenaka
  • Publication number: 20070262353
    Abstract: A semiconductor device according to an embodiment of the present invention includes: a square pole-shaped channel portion made from a first semiconductor layer formed on a substrate, and surrounded with four side faces; a gate electrode formed on a first side face of the channel portion, and a second side face of the channel portion opposite to the first side face through respective gate insulating films; a source region having a conductivity type different from that of the channel portion and being formed on a third side face of the channel portion, the source region including a second semiconductor layer having a lattice constant different from that of the first semiconductor layer and being formed directly on the substrate; and a drain region having a conductivity type different from that of the channel portion and being formed on a fourth side face of the channel portion opposite to the third side face, the drain region including the second semiconductor layer being formed directly on the substrate.
    Type: Application
    Filed: April 26, 2007
    Publication date: November 15, 2007
    Inventors: Nobuyasu Nishiyama, Katsunori Yahashi
  • Publication number: 20060231877
    Abstract: A semiconductor device comprises a semiconductor substrate having a surface of a plane orientation {100}, and a plurality of memory cells formed on the semiconductor substrate. The memory cells each include a capacitor formed in a trench extending from the surface into the semiconductor substrate, and a transistor. The transistor has a first source/drain region connected to the capacitor, a second source/drain region formed apart from the first source/drain region as leaving an interval therebetween and connected to a bit line, and a gate electrode formed over the interval between the first and second source/drain regions and connected to a word line. A transverse section of at least part of the trench is tetragonal. Transverse sections of the trenches in the memory cells are tilted at the substantially same angle against a direction of extension of the word line.
    Type: Application
    Filed: June 17, 2005
    Publication date: October 19, 2006
    Inventors: Keiichi Takenaka, Katsunori Yahashi, Itsuko Sakai
  • Publication number: 20060137988
    Abstract: According to an aspect of the present invention, a semiconductor manufacturing apparatus, including: a treatment chamber configured to house a substrate; an electrode which is disposed in said treatment chamber and on which the substrate is placed; a robot arm configured to convey the substrate to said electrode; and a sensor configured to detect a detection pattern of a focus ring which is disposed on an outer peripheral edge portion of said electrode, surrounds an peripheral edge of the substrate placed on said electrode and has the detection pattern, wherein clearance between the substrate and the focus ring is adjusted based on detection result of said sensor, is provided.
    Type: Application
    Filed: March 16, 2005
    Publication date: June 29, 2006
    Inventors: Katsunori Yahashi, Keiichi Takenaka, Masaki Narita, Itsuko Sakai
  • Publication number: 20060138413
    Abstract: Disclosed is a method of manufacturing a semiconductor device, comprising forming a gate electrode on a main surface of a semiconductor substrate via a gate insulating film, laminating sequentially a first insulating film with oxidation resistance and a silicon film on the main surface of the semiconductor substrate on which the gate electrode is formed, eliminating selectively the silicon film except for a side face of the gate electrode, and oxidizing the silicon film to transform it into a first silicon oxide film, eliminating the first insulating film on the main surface of the semiconductor substrate by using the first silicon oxide film as a mask, and then forming a first impurity layer on the main surface of the semiconductor substrate, laminating a sidewall insulating film thicker than the first silicon oxide film on the side face of the gate electrode on which the first silicon oxide film is formed, and forming a second impurity layer which has the same conduction type as that of the first impurity l
    Type: Application
    Filed: November 23, 2005
    Publication date: June 29, 2006
    Inventors: Katsunori Yahashi, Keiichi Takenaka
  • Publication number: 20060128093
    Abstract: A method of manufacturing a semiconductor device is provided. The method comprises forming a mask member on a surface of a semiconductor substrate; and forming a trench in the semiconductor substrate by selectively etching the semiconductor substrate with a mask of the mask member under a certain pressure. The pressure is changed on arrival of (Etching Depth)/(Aperture Width in said surface) at 30 or more for the remainder of the etching by a factor ranging from 1/2 to 9/10 relative to the pressure at the time of the arrival.
    Type: Application
    Filed: April 14, 2005
    Publication date: June 15, 2006
    Inventors: Keiichi Takenaka, Katsunori Yahashi, Itsuko Sakai, Masaki Narita
  • Publication number: 20040188739
    Abstract: A semiconductor device includes a semiconductor substrate, a trench including a narrowed portion and a main part, a diameter of the narrowed portion being coaxially smaller than a diameter of the trench at the main part, a first capacitor electrode provided in the semiconductor substrate so as to surround the trench inclusive of the narrowed portion, a capacitor insulating film provided along a surface of the first capacitor electrode, a second capacitor electrode provided inside the trench.
    Type: Application
    Filed: January 8, 2004
    Publication date: September 30, 2004
    Inventors: Keiichi Takenaka, Itsuko Sakai, Masaki Narita, Tokuhisa Ohiwa, Atsuo Sanda, Katsunori Yahashi
  • Patent number: 6225650
    Abstract: A GaN group crystal base member comprising a base substrate, a mask layer partially covering the surface of said base substrate to give a masked region, and a GaN group crystal layer grown thereon to cover the mask layer, which is partially in direct contact with the non-masked region of the base substrate, use thereof for a semiconductor element, manufacturing methods thereof and a method for controlling a dislocation line. The manufacturing method of the present invention is capable of making a part in the GaN group crystal layer, which is above a masked region or non-masked region, have a low dislocation density.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: May 1, 2001
    Assignee: Mitsubishi Cable Industries, Ltd.
    Inventors: Kazuyuki Tadatomo, Hiroaki Okagawa, Youichiro Ohuchi, Keiji Miyashita, Kazumasa Hiramatsu, Nobuhiko Sawaki, Katsunori Yahashi, Takumi Shibata