Patents by Inventor Hiroki Shimano

Hiroki Shimano 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: 20010000989
    Abstract: A sub word line is selected when an associated word line and any of sub decode lines are driven to attain a boosted potential. In a sub decoder selectively driving any of the sub decode lines, the pull-down transistors allowing the sub decode line to discharge are turned on successively with time in a pulsing manner.
    Type: Application
    Filed: December 18, 2000
    Publication date: May 10, 2001
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeki Tomishima, Tsukasa Ooishi, Hiroki Shimano
  • Patent number: 6178122
    Abstract: A sub word line is selected when an associated word line and any of sub decode lines are driven to attain a boosted potential. In a sub decoder selectively driving any of the sub decode lines, the pull-down transistors allowing the sub decode line to discharge are turned on successively with time in a pulsing manner.
    Type: Grant
    Filed: December 16, 1998
    Date of Patent: January 23, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeki Tomishima, Tsukasa Ooishi, Hiroki Shimano
  • Patent number: 6163488
    Abstract: In a DRAM with an antifuse for programming a defective address, the antifuse and one electrode of a capacitor are connected to a shared node and the other electrode of the capacitor receives a boost signal. To blow the antifuse, the shared node is set high. To maintain the antifuse unblown, the shared node is set low. Then the boost signal is raised high to boost the shared node. Even when the resistance value of antifuse 1 is decreased, excessive current does not flow. This eliminates the necessity of providing a protection circuit as conventional and thus reduces circuit scale.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: December 19, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroaki Tanizaki, Hiroki Shimano, Shigeki Tomishima
  • Patent number: 6067260
    Abstract: A redundant memory cell column region provided corresponding to respective regular memory cell column regions can have data read and written through a sub I/O line pair and a main I/O line pair independent to those of the regular memory cell column region. Also, one redundant memory cell column region can be connected to a corresponding global I/O line pair G-I/O of any of the regular memory cell column regions via a multiplexer to be replaceable of any of two regular memory cell column regions.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: May 23, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tsukasa Ooishi, Shigeki Tomishima, Hiroki Shimano
  • Patent number: 6058053
    Abstract: In the semiconductor memory device, independent from redundancy determination by a redundancy determining circuit, a word line activating signal (subdecode signal) for setting a word line in a normal block corresponding to a decoded address signal, is activated. A WL driver includes a driver portion for selecting a word line in the normal block, and a driver portion for selecting a spare word line in a redundant block. When redundancy is not to be used as a result of redundancy determination by the redundancy determining circuit, activated subdecode signal is inactivated. If redundancy is to be used as a result of redundancy determination, a corresponding word line is set to the selected state, using the activated subdecode signal. Thus a semiconductor memory device in which substitution can be done at high speed with high efficiency is provided.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: May 2, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takaharu Tsuji, Tsukasa Ooishi, Hiroshi Kato, Shigeki Tomishima, Hiroki Shimano
  • Patent number: 5268321
    Abstract: A semiconductor memory device comprises a p.sup.- -type semiconductor substrate (1), p.sup.+ -type regions (15, 80) formed thereon, n.sup.+ -type regions (6, 7) surrounded with the p.sup.+ -type regions (15, 80), a first gate electrode (2) formed on a charge storage region in the n.sup.+ -type region (6), and a second gate electrode (3) formed on the p.sup.+ -type region (80) and serving as a word line. The p.sup.+ -type regions (15, 80) prevent passage of electrons out of electron-hole pairs induced by alpha rays so as to prevent occurrence of soft errors. An oxide film (16) is formed on the side wall of the second gate electrode (3), a titanium silicide film (17) is formed on the n.sup.+ -type regions (6, 7) and a titanium silicide film (18) is formed on the second gate electrode (3) in a self-aligning manner. Therefore, increase of interconnection resistance of the second gate electrode (3 ) and diffusion resistance of the n.sup.+ -type regions (6, 7) is prevented.
    Type: Grant
    Filed: January 9, 1989
    Date of Patent: December 7, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiro Shimizu, Hiroki Shimano, Masahide Inuishi, Katsuhiro Tsukamoto
  • Patent number: 5249215
    Abstract: X-ray exposure equipment which can effectively converge a synchrotron radiation, which tends to diverge to a great extent in a horizontal direction, to assure a sufficiently high intensity on a lithographic plane and can irradiate X-rays perpendicularly to a full lateral extent of the lithographic plane over an entire exposure area. The X-ray exposure equipment comprises a point X-ray source and a first reflecting mirror having first and second point focuses and disposed such that the first focal point coincides with the location of the X-ray source so as to focus X-rays to the second focal point. A second reflecting mirror is disposed such that the focus thereof substantially coincides with the second focal point of the first reflecting mirror so as to collimate X-rays received from the first reflecting mirror by way of the focusing property thereof in parallel to a principal optical axis of an optical system for X-rays which includes the first and second reflecting mirrors.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: September 28, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hiroki Shimano
  • Patent number: 5164806
    Abstract: An element isolating structure employed for isolating the elements of a semiconductor substrate has an impurity region having a concentration lower than that of a source/drain and a channel stop region, between the source/drain of an MOS transistor formed in an active region, and the channel stop region formed under an LOCOS film.A field shield isolating structure has a low concentrated impurity region between the source/drain of an MOS transistor formed in the active region and the substrate surface region covered by a field shield electrode layer. The low concentrated impurity region improves its junction breakdown voltage in the boundary region with the element isolating region.An improved LOCOS film is formed into an amorphous region on the surface of the substrate by an oblique rotating ion implanting method, and the amorphous region is formed by thermal oxidation. The method suppresses the emergence of a bird's beak.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: November 17, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masao Nagatomo, Hiroki Shimano, Tomonori Okudaira, Yoshinori Okumura
  • Patent number: 5023682
    Abstract: A semiconductor memory device comprises a p.sup.- -type semiconductor substrate (1), thin p.sup.+ -type regions (15, 80) formed thereon, n.sup.+ -type regions (6, 7) surrounded with the p.sup.+ -type regions (15, 80), a first gate electrode (2) formed on a charge storage region in the n.sup.+ -type region (6), and a second gate electrode (3) formed on the p.sup.+ -type region (80) and serving as a word line. The p.sup.+ -type regions (15, 80) prevent passage of electrons out of electron-hole pairs induced by alpha rays so as to prevent occurrence of soft errors. Advantageously, the thin p+ layer used to control threshold voltage for a transfer gate of the device is extended and also used for prevention of such soft errors, thus providing reduced bulk for the device. In order to reduce bulk further, the n+-type regions (6, 7) are also reduced in thickness.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: June 11, 1991
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiro Shimizu, Hiroki Shimano, Masahide Inuishi, Katsuhiro Tsukamoto
  • Patent number: 4702797
    Abstract: A method of manufacturing a semiconductor device comprises the steps of forming memory cell portions (2, 4, 6, 11) on a p.sup.- -type semiconductor substrate (1), forming a gate insulator film (5) and a gate electrode (3) each having a larger width, by approximately 1 .mu.m, than the original width, ion-implanting p-type impurities utilizing the gate insulator film (5) and the gate electrode (3) as masks, to form p.sup.+ -type regions (120, 121), etching the side walls of the gate insulator film (5) and the gate electrode (3) to the original width and then, ion-implanting n-type impurities utilizing these regions as a mask, to form n.sup.+ -type regions (80, 81), and heat-treating these regions (80, 81, 120, 121), to form regions (80a, 81a, 120a, 121a). The p.sup.+ -type regions (120a, 121a) prevent passage of electrons out of electron-hole pairs induced by alpha rays, to prevent occurrence of soft errors. The p.sup.+ -type regions (120a, 121a) are located inside the n.sup.
    Type: Grant
    Filed: December 18, 1986
    Date of Patent: October 27, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroki Shimano, Masahiro Shimizu, Katsuhiro Tsukamoto, Masahide Inuishi