Patents by Inventor Naotaka Hashimoto

Naotaka Hashimoto 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: 5132771
    Abstract: A semiconductor static random access memory having a high .alpha.-ray immunity and a high packing density is provided which is also capable of high-speed operation. A semiconductor memory device comprises static random access memory cells each including a flip-flop circuit. Storage nodes of each flip-flop circuit have respective pn-junctions formed at regions sandwiched between gate electrodes of first insulated gate field effect transistors and gate electrodes of second insulated gate field effect transistors, respectively. The pn-junction has an area smaller than that of a channel portion of the first or second insulated gate field effect transistor.
    Type: Grant
    Filed: April 4, 1990
    Date of Patent: July 21, 1992
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corporation
    Inventors: Toshiaki Yamanaka, Naotaka Hashimoto, Takashi Hashimoto, Akihiro Shimizu, Koichiro Ishibashi, Katsuro Sasaki, Katsuhiro Shimohigashi, Eiji Takeda, Yoshio Sakai, Takashi Nishida, Osamu Minato, Toshiaki Masuhara, Shoji Hanamura, Shigeru Honjo, Nobuyuki Moriwaki
  • Patent number: 4970564
    Abstract: A semiconductor memory device having STC cells wherein major portions of active regions consisting of channel-forming portions are tilted at an angle of 45.degree. with respect to the word lines and the bit lines that meet at right angles with each other, enabling the storage capacity portions to be arranged very densely and sufficiently large capacities to be maintained with very small cell areas. In the semiconductor memory device, furthermore, the storage capacity portions are formed even on the bit lines. Therefore, the bit lines are shielded, the capacitance between the bit lines decreases, and the memory array noise decreases.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: November 13, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Shinichiro Kimura, Naotaka Hashimoto, Yoshio Sakai, Tokuo Kure, Yoshifumi Kawamoto
  • Patent number: 4797717
    Abstract: Each of the memory cells in a SRAM includes two driver MOS transistors, two transfer gate MOS transistors and two load resistances. The gate electrode layers of the MOS transistors are formed from a first-level conductive layer provided on the surface of a semiconductor substrate. The source regions of the two driver MOS transistors in each memory cell are connected in common and further connected to a ground potential point through a second-level conductive layer. The two load resistances in each memory cell are formed from a third-level high-resistance material layer. The second-level conductive layer is formed from a low-resistance material layer. Thus the resistance of the sources of the two driver MOS transistors is lowered.
    Type: Grant
    Filed: April 17, 1987
    Date of Patent: January 10, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Koichiro Ishibashi, Osamu Minato, Toshiaki Masuhara, Yoshio Sakai, Toshiaki Yamanaka, Naotaka Hashimoto, Shoji Hanamura, Nobuyuki Moriwaki, Shigeru Honjyo, Kiyotsugu Ueda