Patents by Inventor Shoji Wakahara

Shoji Wakahara 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: 7042051
    Abstract: Provided is a manufacturing method of a semiconductor device which comprises forming, all over the surface of a substrate below the channel region of a MISFET, a p type impurity layer having a first peak in impurity concentration distribution and another p type impurity layer having a second peak in impurity concentration distribution, each layer having a function of preventing punch-through. Compared with a device having a punch through stopper layer of a pocket structure, the device of the present invention is suppressed in fluctuations in the threshold voltage. Moreover, with a relative increase in the controllable width of a depletion layer, a sub-threshold swing becomes small, thereby making it possible to prevent lowering of the threshold voltage and to improve a switching rate of the MISFET.
    Type: Grant
    Filed: November 19, 2002
    Date of Patent: May 9, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Fumio Ootsuka, Takahiro Onai, Kazuhiro Ohnishi, Shoji Wakahara
  • Patent number: 6806128
    Abstract: With a gate electrode and side wall spacers being used as masks, ions of an n-type impurity are implanted from the normal line direction of a substrate, whereby source/drain diffused regions are formed. Then, ions of an n-type impurity are introduced by oblique implantation having a predetermined angle relative to the normal line direction of the substrate to form an n-type semiconductor region having an impurity concentration higher than source/drain extended regions. By this method, the junction depth of the semiconductor region becomes smaller than that of the source/drain diffused regions and greater than that of the source/drain extended regions.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: October 19, 2004
    Assignee: Renesas Technology Corp.
    Inventors: Fumio Ootsuka, Katsuhiko Ichinose, Shoji Wakahara
  • Publication number: 20030094627
    Abstract: Provided is a manufacturing method of a semiconductor device which comprises forming, all over the surface of a substrate below the channel region of a MISFET, a p type impurity layer having a first peak in impurity concentration distribution and another p type impurity layer having a second peak in impurity concentration distribution, each layer having a function of preventing punch-through. Compared with a device having a punch through stopper layer of a pocket structure, the device of the present invention is suppressed in fluctuations in the threshold voltage. Moreover, with a relative increase in the controllable width of a depletion layer, a sub-threshold swing becomes small, thereby making it possible to prevent lowering of the threshold voltage and to improve a switching rate of the MISFET.
    Type: Application
    Filed: November 19, 2002
    Publication date: May 22, 2003
    Inventors: Fumio Ootsuka, Takahiro Onai, Kazuhiro Ohnishi, Shoji Wakahara
  • Patent number: 6524903
    Abstract: A method of manufacture of a semiconductor device calls for forming, all over the surface of a substrate below the channel region of a MISFET, a p type impurity layer having a first peak in impurity concentration distribution and another p type impurity layer having a second peak in impurity concentration distribution, each layer having a function of preventing punch-through. Compared with a device having a punch through stopper layer with a pocket structure, the device produced by the present method operates in such a way that fluctuations in the threshold voltage are suppressed. Moreover, with a relative increase in the controllable width of a depletion layer, the sub-threshold swing becomes small, thereby making it possible to prevent lowering of the threshold voltage and to improve the switching rate of the MISFET.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: February 25, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Ootsuka, Takahiro Onai, Kazuhiro Ohnishi, Shoji Wakahara
  • Publication number: 20020043665
    Abstract: Provided is a manufacturing method of a semiconductor device which comprises forming, all over the surface of a substrate below the channel region of a MISFET, a p type impurity layer having a first peak in impurity concentration distribution and another p type impurity layer having a second peak in impurity concentration distribution, each layer having a function of preventing punch-through. Compared with a device having a punch through stopper layer of a pocket structure, the device of the present invention is suppressed in fluctuations in the threshold voltage. Moreover, with a relative increase in the controllable width of a depletion layer, a sub-threshold swing becomes small, thereby making it possible to prevent lowering of the threshold voltage and to improve a switching rate of the MISFET.
    Type: Application
    Filed: September 28, 2001
    Publication date: April 18, 2002
    Inventors: Fumio OOtsuka, Takahiro Onai, Kazuhiro Ohnishi, Shoji Wakahara
  • Publication number: 20020005553
    Abstract: With a gate electrode and side wall spacers as masks, ions of an n-type impurity are implanted from the normal line direction of a substrate, whereby source/drain diffused regions are formed. Then, ions of an n-type impurity are introduced by oblique implantation having a predetermined angle relative to the normal line direction of the substrate to form an n-type semiconductor region having an impurity concentration higher than source/drain extended regions. By this method, the junction depth of the semiconductor region becomes smaller than that of the source/drain diffused regions and greater than that of the source/drain extended regions.
    Type: Application
    Filed: July 5, 2001
    Publication date: January 17, 2002
    Inventors: Fumio Ootsuka, Katsuhiko Ichinose, Shoji Wakahara