Patents by Inventor Yukiko Umemoto

Yukiko Umemoto 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).

  • Publication number: 20050258474
    Abstract: A semiconductor device includes a plurality of nonvolatile memory cells (1). Each of the nonvolatile memory cells comprises a MOS type first transistor section (3) used for information storage, and a MOS type second transistor section (4) which selects the first transistor section. The second transistor section has a bit line electrode (16) connected to a bit line, and a control gate electrode (18) connected to a control gate control line. The first transistor section has a source line electrode (10) connected to a source line, a memory gate electrode (14) connected to a memory gate control line, and a charge storage region (11) disposed directly below the memory gate electrode. A gate withstand voltage of the second transistor section is lower than that of the first transistor section.
    Type: Application
    Filed: July 22, 2002
    Publication date: November 24, 2005
    Inventors: Toshihiro Tanaka, Yukiko Umemoto, Mitsuru Hiraki, Yutaka Shinagawa, Masamichi Fujito, Kazufumi Suzukawa, Hiroyuki Tanikawa, Takashi Yamaki, Yoshiaki Kamigaki, Shinichi Minami, Kozo Katayama, Nozomu Matsuzaki
  • Publication number: 20050128815
    Abstract: An erasing current is distributed to reduce a load of an internal power circuit and to decrease the number of drivers for erase. A semiconductor data processing device has: a memory array having nonvolatile memory cells arrayed in a matrix and divided into a plurality of erase blocks each instructed to be erased together; and a control circuit, wherein the control circuit controls both of two kinds of erasing voltages applied to the nonvolatile memory cell in the erase block instructed to be erased together to select an erase sector from the erase block for performing erase for each erase sector, thereby performing the erase for each erase sector in time division. Time division erase can distribute an erasing current. Two kinds of erasing voltages are used to select the erase sector. No specific drivers need be provided for each erase sector.
    Type: Application
    Filed: December 3, 2004
    Publication date: June 16, 2005
    Inventors: Jiro Ishikawa, Takashi Yamaki, Toshihiro Tanaka, Yukiko Umemoto, Akira Kato
  • Patent number: 6747895
    Abstract: This inventing is intended to shorten data deletion time of a nonvolatile semiconductor memory such as a flash memory (EEPROM). When deleting data written to a memory cell MC0 among flash memory cells MC0 to MC2 formed on a semiconductor substrate PSUB through a separation region NiSO, a voltage of p type well PWL0 in which the memory cell MC0 is formed is raised to 10V and a voltage of the separation region NiSO is raised to 12V by using a voltage application unit different from a voltage application unit applying a voltage to the p type well PWL0. As a result, parasitic capacitances Ca1 and Ca2 generated between p type wells PWL1 and PWL2 in which the unselected memory cells MC1 and MC2 are formed and the separation region NiSO, respectively, and a parasitic capacitance Cb generated between the separation region NiSO and the semiconductor substrate PSUB are charged by the voltage application units.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: June 8, 2004
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Yukiko Umemoto, Toshihiro Tanaka, Hiroyuki Tanikawa, Yutaka Shinagawa
  • Publication number: 20020159291
    Abstract: This inventing is intended to shorten data deletion time of a nonvolatile semiconductor memory such as a flash memory (EEPROM). When deleting data written to a memory cell MC0 among flash memory cells MC0 to MC2 formed on a semiconductor substrate PSUB through a separation region NiSO, a voltage of p type well PWL0 in which the memory cell MC0 is formed is raised to 10V and a voltage of the separation region NiSO is raised to 12V by using a voltage application unit different from a voltage application unit applying a voltage to the p type well PWL0. As a result, parasitic capacitances Ca1and Ca2 generated between p type wells PWL1 and PWL2 in which the unselected memory cells MC1 and MC2 are formed and the separation region NiSO, respectively, and a parasitic capacitance Cb generated between the separation region NiSO and the semiconductor substrate PSUB are charged by the voltage application units.
    Type: Application
    Filed: February 27, 2002
    Publication date: October 31, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Yukiko Umemoto, Toshihiro Tanaka, Hiroyuki Tanikawa, Yutaka Shinagawa