Patents by Inventor Takeshi Kitani

Takeshi Kitani 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: 9553084
    Abstract: According to the present invention, a switching element includes a substrate, a first gate pad formed on the substrate, a second gate pad formed on the substrate, a first resistor portion formed on the substrate, the first resistor portion connecting the first gate pad and the second gate pad to each other, and a cell region formed on the substrate and connected to the first gate pad. Thus, measurement of the gate resistance value and selection from gate resistances of the switching element can be performed after the completion of the gate-resistor-incorporating-type switching element.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: January 24, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shigeru Hasegawa, Kazuhiro Morishita, Takeshi Kitani
  • Publication number: 20160148927
    Abstract: According to the present invention, a switching element includes a substrate, a first gate pad formed on the substrate, a second gate pad formed on the substrate, a first resistor portion formed on the substrate, the first resistor portion connecting the first gate pad and the second gate pad to each other, and a cell region formed on the substrate and connected to the first gate pad. Thus, measurement of the gate resistance value and selection from gate resistances of the switching element can be performed after the completion of the gate-resistor-incorporating-type switching element.
    Type: Application
    Filed: September 9, 2013
    Publication date: May 26, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shigeru HASEGAWA, Kazuhiro MORISHITA, Takeshi KITANI
  • Patent number: 9184306
    Abstract: A silicon carbide semiconductor device of the present invention comprises a silicon carbide drift layer formed on a silicon carbide substrate, a P-type region formed in a surface layer of the silicon carbide drift layer, and a Schottky electrode formed above the silicon carbide drift layer correspondingly to a forming portion of the P-type region. The P-type region is formed of a plurality of unit cells arranged therein. Each of the unit cells has at least a first distribution region in which the P-type impurity is distributed at first concentration and a second distribution region in which the P-type impurity is distributed at second concentration higher than the first concentration. With this structure, it is possible to provide a silicon carbide semiconductor device in which a sufficient breakdown voltage can be achieved with less number of ion implantations.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: November 10, 2015
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takeshi Kitani, Yoichiro Tarui
  • Publication number: 20140077226
    Abstract: A silicon carbide semiconductor device of the present invention comprises a silicon carbide drift layer formed on a silicon carbide substrate, a P-type region formed in a surface layer of the silicon carbide drift layer, and a Schottky electrode formed above the silicon carbide drift layer correspondingly to a forming portion of the P-type region. The P-type region is formed of a plurality of unit cells arranged therein. Each of the unit cells has at least a first distribution region in which the P-type impurity is distributed at first concentration and a second distribution region in which the P-type impurity is distributed at second concentration higher than the first concentration. With this structure, it is possible to provide a silicon carbide semiconductor device in which a sufficient breakdown voltage can be achieved with less number of ion implantations.
    Type: Application
    Filed: June 28, 2013
    Publication date: March 20, 2014
    Inventors: Takeshi KITANI, Yoichiro TARUI
  • Patent number: 6753246
    Abstract: The semiconductor device includes a semiconductor substrate and, in an element isolating region in the semiconductor substrate, a first active area A/A dummy pattern and a second A/A dummy pattern having a pitch smaller than that of the first A/A dummy pattern. Placement of the first A/A dummy pattern and placement of the second A/A dummy pattern are carried out in separate steps. The semiconductor substrate may be divided into a plurality of mesh regions, and a dummy pattern may be placed in each mesh region according to an area of the mesh region being occupied by an element pattern located therein.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: June 22, 2004
    Assignee: Renesas Technology Corp.
    Inventors: Hiroshi Kawashima, Masakazu Okada, Takeshi Kitani, Motoshige Igarashi
  • Publication number: 20030178647
    Abstract: The semiconductor device includes a semiconductor substrate and, in an element isolating region in the semiconductor substrate, a first active area A/A dummy pattern and a second A/A dummy pattern having a pitch smaller than that of the first A/A dummy pattern. Placement of the first A/A dummy pattern and placement of the second A/A dummy pattern are carried out in separate steps. The semiconductor substrate may be divided into a plurality of mesh regions, and a dummy pattern may be placed in each mesh region according to an area of the mesh region being occupied by an element pattern located therein.
    Type: Application
    Filed: April 22, 2003
    Publication date: September 25, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Hiroshi Kawashima, Masakazu Okada, Takeshi Kitani, Motoshige Igarashi
  • Patent number: 6563148
    Abstract: The semiconductor device includes a semiconductor substrate and, in an element isolating region in the semiconductor substrate, a first active area A/A dummy pattern and a second A/A dummy pattern having a pitch smaller than that of the first A/A dummy pattern. Placement of the first A/A dummy pattern and placement of the second A/A dummy pattern are carried out in separate steps. The semiconductor substrate may be divided into a plurality of mesh regions, and a dummy pattern may be placed in each mesh region according to an area of the mesh region being occupied by an element pattern located therein.
    Type: Grant
    Filed: April 10, 2001
    Date of Patent: May 13, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroshi Kawashima, Masakazu Okada, Takeshi Kitani, Motoshige Igarashi
  • Patent number: 6555887
    Abstract: A semiconductor device with a polycide interconnection including a refractory metal silicide film improved in adherence with an interlayer insulation film, and a method of fabricating such a semiconductor device are provided. The local impurity concentration of a tungsten silicide film in the proximity of the interface between an interlayer oxide film and the tungsten silicide film is set to 5×1019 atms/cm3-2×1022 atms/cm3.
    Type: Grant
    Filed: August 5, 1999
    Date of Patent: April 29, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Kitani, Takeru Matsuoka, Masayoshi Shirahata
  • Patent number: 6461946
    Abstract: Both P type and N type impurities are implanted from a plurality of directions. The tilt angle &thgr; of the implantation direction against the normal of the main surface of a semiconductor substrate is fixed to 10°, and the deflection angle &phgr; is set to such four directions (X, X+90°, X+180°, and X+270°, where X is an arbitrary angle) that projecting components of a vector indicating the implantation direction are opposed to each other on two lines that cross each other at right angles along the main surface of the semiconductor substrate. Thereby, the dependency of the breakdown voltage of element isolation on the direction of a well boundary is suppressed to realize a high breakdown voltage of element isolation in all directions.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: October 8, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Kitani, Katsumi Eikyu, Masao Sugiyama
  • Patent number: 6424042
    Abstract: An interlayer film layer is formed on an (N−1)-th interconnection Layer via a barrier film, and an N-th interconnection layer is formed on the interlayer film layer. An interconnection having a Damascene structure is formed in the interconnection layer and the interlayer film layer. The interconnection has an wiring portion having a narrow line width and a pad portion having a wide line width. A recess corresponding to the wiring portion and the pad portion is provided in an insulating film of the interconnection layer. A recess corresponding to the pad portion is provided in an insulating film of the interlayer film layer. A barrier metal and a metal film are deposited in both the recesses, and unnecessary portions of the barrier metal and the metal film are removed by CMP, to form a multilayer interconnection structure.
    Type: Grant
    Filed: February 17, 2000
    Date of Patent: July 23, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeshi Kitani
  • Publication number: 20020033488
    Abstract: The semiconductor device includes a semiconductor substrate and, in an element isolating region in the semiconductor substrate, a first active area A/A dummy pattern and a second A/A dummy pattern having a pitch smaller than that of the first A/A dummy pattern. Placement of the first A/A dummy pattern and placement of the second A/A dummy pattern are carried out in separate steps. The semiconductor substrate may be divided into a plurality of mesh regions, and a dummy pattern may be placed in each mesh region according to an area of the mesh region being occupied by an element pattern located therein.
    Type: Application
    Filed: April 10, 2001
    Publication date: March 21, 2002
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroshi Kawashima, Masakazu Okada, Takeshi Kitani, Motoshige Igarashi
  • Publication number: 20010036714
    Abstract: Both P type and N type impurities are implanted from a plurality of directions. The tilt angle &thgr; of the implantation direction against the normal of the main surface of a semiconductor substrate is fixed to 10°, and the deflection angle &phgr; is set to such four directions (X, X+90°, X+180°, and X+270°, where X is an arbitrary angle) that projecting components of a vector indicating the implantation direction are opposed to each other on two lines that cross each other at right angles along the main surface of the semiconductor substrate. Thereby, the dependency of the breakdown voltage of element isolation on the direction of a well boundary is suppressed to realize a high breakdown voltage of element isolation in all directions.
    Type: Application
    Filed: April 30, 2001
    Publication date: November 1, 2001
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takeshi Kitani, Katsumi Eikyu, Masao Sugiyama