Patents by Inventor Takahiro Kumauchi

Takahiro Kumauchi 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: 20030040183
    Abstract: Disclosed is a technique for reducing the leak current by reducing contamination of metal composing a polymetal gate of a MISFET. Of a polycrystalline silicon film, a WN film, a W film, and a cap insulating film formed on a gate insulating film on a p-type well (semiconductor substrate), the cap insulating film, the W film, and the WN film are etched and the over-etching of the polycrystalline silicon film below them is performed. Then, a sidewall film is formed on sidewalls of these films. Thereafter, after etching the polycrystalline silicon film with using the sidewall film as a mask, a thermal treatment is performed in an oxidation atmosphere, by which a light oxide film is formed on the sidewall of the polycrystalline silicon film. As a result, the contamination on the gate insulating film due to the W and the W oxide can be reduced, and also, the diffusion of these materials into the semiconductor substrate (p-type well) and the resultant increase of the leak current can be prevented.
    Type: Application
    Filed: August 20, 2002
    Publication date: February 27, 2003
    Inventors: Hiroshi Kujirai, Kousuke Okuyama, Kazuhiro Hata, Kiyonori Oyu, Ryo Nagai, Hiroyuki Uchiyama, Takahiro Kumauchi, Teruhisa Ichise
  • Publication number: 20030001214
    Abstract: An active region (L) with a metal insulator semiconductor field effect transistor (MISFET) (Qs) formed therein for selection of a DRAM memory cell, which makes up a memory cell of the DRAM, is arranged to have an island-like pattern that linearly extends in an X direction on one principal surface of a semiconductor substrate (1). The memory-cell selection MISFET (Qs) has an insulated gate electrode (7) (word line WL) that extends along a Y direction on the principal surface of the semiconductor substrate (1) with the same width kept along the length thereof, which gate electrode is arranged to oppose another gate electrode (7) (word line WL) adjacent thereto at a prespecified distance or pitch that is narrower than said width.
    Type: Application
    Filed: August 27, 2002
    Publication date: January 2, 2003
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Isamu Asano, Norio Hasegawa, Keizo Kawakita
  • Patent number: 6483136
    Abstract: An active region (L) with a metal insulator semiconductor field effect transistor (MISFET) (Qs) formed therein for selection of a DRAM memory cell, which makes up a memory cell of the DRAM, is arranged to have an island-like pattern that linearly extends in an X direction on one principal surface of a semiconductor substrate (1). The memory-cell selection MISFET (Qs) has an insulated gate electrode (7) (word line WL) that extends along a Y direction on the principal surface of the semiconductor substrate (1) with the same width kept along the length thereof, which gate electrode is arranged to oppose another gate electrode (7) (word line WL) adjacent thereto at a prespecified distance or pitch that is narrower than said width.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: November 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Isamu Asano, Norio Hasegawa, Keizo Kawakita
  • Publication number: 20020045309
    Abstract: In a process for manufacturing a semiconductor integrated circuit device having a MISFET, in order that a shallow junction between the source/drain of the MISFET and a semiconductor substrate may be realized by reducing the number of heat treatment steps, all conductive films to be deposited on the semiconductor substrate are deposited at a temperature of 500° C. or lower at a step after the MISFET has been formed. Moreover, all insulating films to be deposited over the semiconductor substrate are deposited at a temperature of 500° C. or lower at a step after the MISFET has been formed.
    Type: Application
    Filed: October 13, 1999
    Publication date: April 18, 2002
    Inventors: MAKOTO YOSHIDA, TAKAHIRO KUMAUCHI, YOSHITAKA TADAKI, KAZUHIKO KAJIGAYA, HIDEO AOKI, ISAMU ASANO
  • Publication number: 20010001717
    Abstract: Oxidation on the surface of a film of refractory metal constituting a gate electrode (word line WL) is suppressed by forming an insulation film constituting a cap insulation film of the gate electrode (word line WL) at a temperature of 500° C. or lower. Further, oxidation on the surface of the refractory metal film exposed to the side wall of the gate electrode (word line WL) is suppressed by forming an insulation film constituting the side wall spacer of the gate electrode (word line WL) at a temperature of 500° C. or lower.
    Type: Application
    Filed: December 22, 2000
    Publication date: May 24, 2001
    Inventors: Takahiro Kumauchi, Makoto Yoshida, Kazuhiko Kajigaya
  • Patent number: 5981369
    Abstract: In a process for manufacturing a semiconductor integrated circuit device having a MISFET, in order that a shallow junction between the source/drain of the MISFET and a semiconductor substrate may be realized by reducing the number of heat treatment steps, all conductive films to be deposited on the semiconductor substrate are deposited at a temperature of 500.degree. C. or lower at a step after the MISFET has been formed. Moreover, all insulating films to be deposited over the semiconductor substrate are deposited at a temperature of 500.degree. C. or lower at a step after the MISFET has been formed.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: November 9, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yoshida, Takahiro Kumauchi, Yoshitaka Tadaki, Kazuhiko Kajigaya, Hideo Aoki, Isamu Asano
  • Patent number: 5846869
    Abstract: A method of manufacturing a bipolar transistor having an improved polysilicon emitter is disclosed. More specifically, hydrogen terminations or OH group terminations adhered (bonded) to an emitter-forming region are eliminated by a heat treatment in an inert gas atmosphere before forming emitter polysilicon. Subsequently, an amorphous silicon film for forming an emitter polysilicon is formed at a low temperature.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: December 8, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Hashimoto, Hideo Miura, Toshiyuki Kikuchi, Toshiyuki Mine, Yoichi Tamaki, Takahiro Kumauchi
  • Patent number: 5773340
    Abstract: A method of manufacturing an improved bipolar transistor or BiCMOS having a phosphorus-doped polysilicon emitter electrode is disclosed. The method comprises forming an emitter electrode wherein a phosphorus-doped amorphous silicon film is deposited at temperature not higher than 540.degree. C. and then subjected to low temperature annealing treatment at a temperature of 600.degree. C. to 750.degree. C., under which the amorphous silicon is converted to a polysilicon and the phosphorus present in the amorphous silicon film is diffused into a base region to form an emitter region, followed by high temperature/short time annealing treatment at a temperature of 900.degree. C. to 950.degree. C. so that an activation rate of an impurity in a boron-doped polysilicon base electrode or source-drain regions of MOS.cndot.FET is improved.
    Type: Grant
    Filed: November 28, 1995
    Date of Patent: June 30, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takahiro Kumauchi, Takashi Hashimoto, Osamu Kasahara, Satoshi Yamamoto, Yoichi Tamaki, Takeo Shiba, Takashi Uchino