Patents by Inventor Masao Sakuraba

Masao Sakuraba 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: 6800544
    Abstract: A metal-semiconductor junction comprising a wiring metal layer and a semiconductor layer. To reduce the contact resistance of the junction, a region doped with an n- or p-type impurity and having a high carrier concentration of 1021 cm−3 or more is provided in a near-surface part of the semiconductor layer (at a distance of 10 nm or less from the metal layer. The high-carrier concentration region is composed of n- or p-type impurity layers and IV-group semiconductor layers that have been alternately deposited upon another by means of, for example, vapor-phase growth.
    Type: Grant
    Filed: August 19, 2002
    Date of Patent: October 5, 2004
    Assignee: President of Tohoku University
    Inventors: Junichi Murota, Yosuke Shimamune, Masao Sakuraba, Takashi Matsuura
  • Publication number: 20040033686
    Abstract: A metal-semiconductor junction comprising a wiring metal layer and a semiconductor layer. To reduce the contact resistance of the junction, a region doped with an n- or p-type impurity and having a high carrier concentration of 1021 cm−3 or more is provided in a near-surface part of the semiconductor layer (at a distance of 10 nm or less from the metal layer. The high-carrier concentration region is composed of n -or p-type impurity layers and IV-group semiconductor layers that have been alternately deposited upon another by means of, for example, vapor-phase growth.
    Type: Application
    Filed: August 19, 2002
    Publication date: February 19, 2004
    Inventors: Junichi Murota, Yosuke Shimamune, Masao Sakuraba, Takashi Matsuura
  • Patent number: 6621145
    Abstract: A metal-semiconductor junction comprises a wiring metal layer and a semiconductor layer. To reduce the contact resistance of the junction, a region doped with an n- or p-type impurity and having a high carrier concentration of 1021 cm−3 or more is provided in a near-surface part of the semiconductor layer (at a distance of 10 nm or less from the metal layer. The high-carrier concentration region is composed of n- or p-type impurity layers and IV-group semiconductor layers that have been alternately deposited upon another by means of, for example, vapor-phase growth.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: September 16, 2003
    Assignee: President of Tohoku University
    Inventors: Junichi Murota, Yosuke Shimamune, Masao Sakuraba, Takashi Matsuura
  • Publication number: 20020109135
    Abstract: The MOS field-effect transistor aims to enhance the electron mobility and the hole mobility in the channel portion by employing the strained-Si/SiGe (or Si/SiGeC) structure. Crystallinity of such a heterostructure is maintained in a preferable state, shortening of the effective channel length is prevented, diffusion of Ge is prevented and the resistance of the source layer and the drain layer is reduced. The channel region has a layered structure formed by stacking the Si layer and, the SiGe or SiGeC layer in order from the surface. The source layer and the drain layer formed of SiGe or SiGeC including high concentration impurity atoms providing a desired conduction type, are in contact with both end surfaces of the channel region. The surfaces of the source layer and the drain layer have a shape rising upwardly from the bottom portion of the gate electrode.
    Type: Application
    Filed: February 5, 2002
    Publication date: August 15, 2002
    Inventors: Junichi Murota, Masao Sakuraba, Takashi Matsuura, Toshiaki Tsuchiya
  • Publication number: 20020027285
    Abstract: A metal-semiconductor junction comprising a wiring metal layer and a semiconductor layer. To reduce the contact resistance of the junction, a region doped with an n- or p-type impurity and having a high carrier concentration of 1021 cm−3 or more is provided in a near-surface part of the semiconductor layer (at a distance of 10 nm or less from the metal layer. The high-carrier concentration region is composed of n- or p-type impurity layers and IV-group semiconductor layers that have been alternately deposited upon another by means of, for example, vapor-phase growth.
    Type: Application
    Filed: May 30, 2001
    Publication date: March 7, 2002
    Inventors: Junichi Murota, Yosuke Shimamune, Masao Sakuraba, Takashi Matsuura
  • Publication number: 20020008289
    Abstract: A semiconductor device is disclosed which allows for ease of fabrication of CMOS LSI chips and is adapted to increase the mobility of electrons and holes. The semiconductor device comprises a substrate, an insulating layer formed over the substrate, and a stacked Si/SiGe/Si region comprising a first layer of Si, a layer of SiGe, and a second layer of Si which are sequentially formed in this order on the insulating layer. The topmost second layer of Si and the layer of SiGe are strained due to the difference in lattice constant between each layer in the stacked Si/SiGe/Si region. An n-MOSFET and a p-MOSFET are formed in the stacked region. The n-MOSFET has a surface channel consisting of the second Si layer, whereas the p-MOSFET has a double channel of a buried channel consisting of the SiGe layer and a surface channel consisting of the second Si layer.
    Type: Application
    Filed: July 20, 2001
    Publication date: January 24, 2002
    Inventors: Junichi Murota, Toshiaki Tsuchiya, Takashi Matsuura, Masao Sakuraba
  • Patent number: 5705224
    Abstract: A vapor deposition apparatus and method in which pulse waveform light is applied to a sample sealed in a reaction chamber. The sample is exposed to gaseous material while the pulse waveform light is applied creating one or plural atomic layers. Alternate layers of plural substances or alternate multiple layers of plural substances can be formed by alternating the introduction of gaseous materials with the application of pulse waveform light.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: January 6, 1998
    Assignee: Kokusai Electric Co., Ltd.
    Inventors: Junichi Murota, Shoichi Ono, Masao Sakuraba, Nobuo Mikoshiba, Harushige Kurokawa, Fumihide Ikeda