Patents by Inventor Michihiko Mifuji

Michihiko Mifuji 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: 9082654
    Abstract: A semiconductor device of the present invention includes a semiconductor substrate, stripe-shaped trenches for separating the semiconductor substrate into a plurality of active regions, a buried film having a projecting portion that projects from the semiconductor substrate, buried into the trenches, a source region and drain region of a second conductivity type, which are a pair of regions formed in the active region, for providing a channel region of a first conductivity type for a region therebetween, and a floating gate consisting of a single layer striding across the source region and the drain region, projecting beyond the projecting portion in a manner not overlapping the projecting portion, in which an aspect ratio of the buried film is 2.3 to 3.67.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: July 14, 2015
    Assignee: ROHM CO., LTD.
    Inventors: Kunihiko Iwamoto, Bungo Tanaka, Michihiko Mifuji
  • Publication number: 20150137314
    Abstract: The semiconductor device of the present invention includes an insulating layer, a high voltage coil and a low voltage coil which are disposed in the insulating layer at an interval in the vertical direction, a low potential portion which is provided in a low voltage region disposed around a high voltage region for the high voltage coil in planar view and is connected with potential lower than the high voltage coil, and an electric field shield portion which is disposed between the high voltage coil and the low voltage region and includes an electrically floated metal member.
    Type: Application
    Filed: November 10, 2014
    Publication date: May 21, 2015
    Applicant: ROHM CO., LTD.
    Inventors: Kosei OSADA, Isamu NISHIMURA, Tetsuya KAGAWA, Daiki YANAGISHIMA, Toshiyuki ISHIKAWA, Michihiko MIFUJI, Satoshi KAGEYAMA, Nobuyuki KASAHARA
  • Publication number: 20140353737
    Abstract: A semiconductor device of the present invention includes a semiconductor substrate, stripe-shaped trenches for separating the semiconductor substrate into a plurality of active regions, a buried film having a projecting portion that projects from the semiconductor substrate, buried into the trenches, a source region and drain region of a second conductivity type, which are a pair of regions formed in the active region, for providing a channel region of a first conductivity type for a region therebetween, and a floating gate consisting of a single layer striding across the source region and the drain region, projecting beyond the projecting portion in a manner not overlapping the projecting portion, in which an aspect ratio of the buried film is 2.3 to 3.67.
    Type: Application
    Filed: May 29, 2014
    Publication date: December 4, 2014
    Applicant: ROHM CO., LTD.
    Inventors: Kunihiko IWAMOTO, Bungo TANAKA, Michihiko MIFUJI
  • Publication number: 20140239445
    Abstract: A semiconductor device has a resistor area and wiring area selectively disposed on a semiconductor substrate. In this semiconductor device, a second interlayer insulating film is formed above the semiconductor substrate, and a thin-film resistor is disposed on the second interlayer insulating film in the resistor area. Vias that contact the thin-film resistor from below are formed in the second interlayer insulating film. A wiring line is disposed on the second interlayer insulating film in the wiring area. A dummy wiring line that covers the thin-film resistor from above is disposed in a third wiring layer that is in the same layer as the wiring line, and an insulating film is interposed between the thin-film resistor and the dummy wiring line.
    Type: Application
    Filed: February 14, 2014
    Publication date: August 28, 2014
    Applicant: ROHM CO., LTD.
    Inventors: lsamu Nishimura, Michihiko Mifuji, Kazumasa Nishio
  • Patent number: 8384150
    Abstract: A semiconductor device of the present invention includes vertical double diffused MOS transistor. A gate electrode of the vertical double diffused MOS transistor is disposed within a trench formed on a semiconductor substrate and projects from a surface of the semiconductor substrate. On a side surface of the gate electrode, a side wall is formed. On the surface of the semiconductor substrate and a surface of the gate electrode, a metal silicide film is formed.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: February 26, 2013
    Assignee: Rohm Co., Ltd.
    Inventors: Michihiko Mifuji, Ryuta Maruyama, Masaki Hino
  • Publication number: 20120132984
    Abstract: A contact plug 40 electrically connected to an impurity diffusion region between sidewalls of an adjacent pair of memory cells 1 is provided to pass through an interlayer dielectric film 18. A side wall of a contact hole 41 is covered with a sealing film 42 denser than the interlayer dielectric film 18. The contact plug 40 includes a barrier metal film 43 formed to cover a surface of the sealing film 42 and a bottom surface portion of the contact hole 41 and a metal plug 44 embedded in the contact hole 41 in a state surrounded by the barrier metal film 43.
    Type: Application
    Filed: February 2, 2012
    Publication date: May 31, 2012
    Applicant: ROHM CO., LTD.
    Inventors: Michihiko Mifuji, Yuichi Nakao, Toshikazu Mizukoshi, Bungo Tanaka, Taku Shibaguchi, Gentaro Morikawa
  • Publication number: 20070164353
    Abstract: A semiconductor device of the present invention includes vertical double diffused MOS transistor. A gate electrode of the vertical double diffused MOS transistor is disposed within a trench formed on a semiconductor substrate and projects from a surface of the semiconductor substrate. On a side surface of the gate electrode, a side wall is formed. On the surface of the semiconductor substrate and a surface of the gate electrode, a metal silicide film is formed.
    Type: Application
    Filed: November 28, 2006
    Publication date: July 19, 2007
    Applicant: ROHM CO., LTD.
    Inventors: Michihiko Mifuji, Ryuta Maruyama, Masaki Hino
  • Patent number: 6169040
    Abstract: A USG layer 26 is formed to cover an aluminum wiring 24 deposited a field oxide film 22. An organic SOG layer 28 whose thick layer can be easily formed is formed in a groove on the surface of the USG layer 26. Thus, the unevenness of the surface of the USG layer 26 can be relaxed in a degree. Further, an USG layer 30 is formed thereon is formed through the vapor phase growth technique using the high density plasma which can realize excellent embedding. Accordingly, the inter-metal dielectric film 32 having a flat upper surface can be formed. Further, the SOG step is carried out only once in the step of forming the organic SOG layer 28, thereby reducing the production cost. Further, since the organic SOG layer 28 can be encircled by the USG layers 26 and 39 having good film quality, even if the material of the organic SOG layer 28 is not so good, the inter-metal dielectric film 32 with an excellent dielectric property can be formed.
    Type: Grant
    Filed: October 19, 1999
    Date of Patent: January 2, 2001
    Assignee: Rohm Co., Ltd.
    Inventors: Michihiko Mifuji, Satoshi Kageyama