Patents by Inventor Katsuyoshi Tara

Katsuyoshi Tara 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).

  • Semiconductor device
    Patent number: 7012285
    Abstract: A semiconductor device whose insertion loss is reduced and isolation characteristics are improved in a high frequency band by reducing the capacitance component when an FET is off is provided. FETs (30a, 30b) having a gate electrode with a gate length of not more than 0.8 ?m are formed on a semiconductor substrate in which a buffer layer (24) having an impurity concentration of at least 1010 cm?3 and at most 1014 cm?3 is formed on a semi-insulating semiconductor (25) having at least 1014 cm?3 and at most 1016 cm?3 p-type or n-type impurities and an active layer (23) having a p-type or n-type impurity concentration of at least 1015 cm?3 and at most 1017 cm?3 is formed on the buffer layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: March 14, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tadayoshi Nakatsuka, Toshiharu Tambo, Takahiro Kitazawa, Akiyoshi Tamura, Katsuyoshi Tara
  • Semiconductor device
    Publication number: 20040026742
    Abstract: A semiconductor device whose insertion loss is reduced and isolation characteristics are improved in a high frequency band by reducing the capacitance component when an FET is off is provided. FETs (30a, 30b) having a gate electrode with a gate length of not more than 0.8 &mgr;m are formed on a semiconductor substrate in which a buffer layer (24) having an impurity concentration of at least 1010 cm−3 and at most 1014 cm−3 is formed on a semi-insulating semiconductor (25) having at least 1014 cm−3 and at most 1016 cm−3 p-type or n-type impurities and an active layer (23) having a p-type or n-type impurity concentration of at least 1015 cm−3 and at most 1017 cm−3 is formed on the buffer layer.
    Type: Application
    Filed: May 8, 2003
    Publication date: February 12, 2004
    Inventors: Tadayoshi Nakatsuka, Toshiharu Tambo, Takahiro Kitazawa, Akiyoshi Tamura, Katsuyoshi Tara