Patents by Inventor Takeshi Hamamoto

Takeshi Hamamoto 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: 5910927
    Abstract: A memory device having a smaller circuit area but efficiently used is provided. A plurality of main word lines (MWL) extending in a row direction are connected through respective bank latches (BL) to a single global word line (GWL) extending across banks (BANK0, BANK1). Selective activation of an enable signal (BLE) and the global word line (GWL) selects one of the bank latches (BL) to selectively activate an associated main word line (MWL). This state is held by the selected bank latch (BL) after the enable signal (BLE) is inactivated. Then, another enable signal (BLE) is activated to selectively activate another main word line (MWL). Sub-decoders (SD) connected to the main word lines (MWL) are selected independently of each other to independently activate word lines (WL) for each bank (BANK).
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: June 8, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Masaki Tsukude
  • Patent number: 5895946
    Abstract: A random access memory device includes a semiconductive substrate having a surface in which a groove pattern is formed to provide a plurality of rows and columns of island portions. A plurality of trenches are formed in the island portions, which are provided with an array of memory cells arranged in rows and columns. Each of these memory cells consists of a capacitor and a metal oxide semiconductor (MOS) transistor which are stacked on each other in a corresponding one of the trenches. Parallel word lines are coupled to the rows of memory cells, and parallel bit lines are coupled to the columns of memory cells. An insulative layer is buried in each groove for causing adjacent ones of the island portions to be electrically isolated from each other.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: April 20, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Fumio Horiguchi
  • Patent number: 5841705
    Abstract: When an external RAS and external CAS are input to a RAS buffer and a CAS buffer, an internal RAS and an internal CAS are generated. The internal RAS is input to a clock generating circuit and a CBR mode determination circuit and the internal CAS is input to the CBR mode determination circuit. The clock generating circuit outputs a pump clock to first and second WL pumps upon input of internal RAS, and the first WL pump supplies charge to a Vpp power supply. If CAS is input prior to RAS during refresh operation, CBR mode determination circuit inputs a CBR mode signal to the second WL pump which supplies charge to Vpp power supply together with the first WL pump when the pump clock and the CBR mode signal is input thereto.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: November 24, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Kiyohiro Furutani, Yoshikazu Morooka
  • Patent number: 5838038
    Abstract: A semiconductor memory device includes active regions arranged on a semiconductor substrate such that those of the active regions which are adjacent in the word line direction deviate in the bit line direction, MOS transistors respectively formed in the active regions and each having a source and a drain one of which is connected to the bit line, a plurality of trenches each arranged to another set of source an drain regions and arranged to deviate in the word line direction in the respective active regions, those of the trenches which are adjacent with a through word line disposed therebetween being arranged to deviate in the bit line direction so as to be set closer to each other, a plurality of storage electrodes respectively formed in the trenches with capacitor insulative films disposed therebetween, and connection electrodes arranged between the word lines and each connecting the other of the source and drain to the storage electrode.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 17, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisaburo Takashima, Shigeyoshi Watanabe, Tohru Ozaki, Takeshi Hamamoto, Yukihito Oowaki
  • Patent number: 5838335
    Abstract: A graphic data processing device is proposed that enables high-speed graphic processing for repeated graphic in semiconductor layout data. A plurality of sets of systematic array graphic data are inputted in an input device, the inputted systematic array graphic data are checked in an array information analyzer to confirm that the grid widths of the array grids of the different data are equal, and data are converted at an array graphic converter to systematic array graphic data sharing common array grid information. The data can then undergo graphic processing at a graphic processor in the form of systematic array graphic data without further alteration.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: November 17, 1998
    Assignee: NEC Corporation
    Inventor: Takeshi Hamamoto
  • Patent number: 5764562
    Abstract: A memory cell is connected between a bit line and an electrode node. The memory cell includes a transistor connected to the bit line and a capacitor connected to the electrode node. In the operation, the potential of a word line is raised after the potential of the electrode node is lowered to the L-level. Thereby, electric charges are read onto the bit line from only the memory cell connected to the electrode node of which potential is selectively lowered. Therefore, only the selected bit line among the plurality of bit lines can be operated. Consequently, the power consumption can be reduced.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: June 9, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeshi Hamamoto
  • Patent number: 5736760
    Abstract: A MOS random access memory device includes a semiconductor substrate having a trench formed therein, and an array of memory cells on the substrate. Each of the memory cells includes a 1-bit data-storage capacitor and a transfer-gate MOS transistor. The capacitor includes an insulated layer buried in the trench, which serves as a storage node. An island-shaped semiconductor layer covers the storage-node layer at least partially on the substrate, and is coupled thereto. The transistor has a source and a drain defining a channel region therebetween in the substrate, and an insulated gate overlying the channel region. One of the source and drain is directly coupled to the island-shaped layer, while the other of them is contacted with a corresponding data-transfer line (bit line) associated therewith.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: April 7, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Hieda, Masami Aoki, Takeshi Hamamoto
  • Patent number: 5731609
    Abstract: A random access memory device includes a semiconductive substrate having a surface in which a groove pattern is formed to provide a plurality of rows and columns of island portions. A plurality of trenches are formed in the island portions, which are provided with an array of memory cells arranged in rows and columns. Each of these memory cells consists of a capacitor and a metal oxide semiconductor (MOS) transistor which are stacked on each other in a corresponding one of the trenches. Parallel word lines are coupled to the rows of memory cells, and parallel bit lines are coupled to the columns of memory cells. An insulative layer is buried in each groove for causing adjacent ones of the island portions to be electrically isolated from each other.
    Type: Grant
    Filed: February 24, 1997
    Date of Patent: March 24, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Fumio Horiguchi
  • Patent number: 5699303
    Abstract: When an external RAS and external CAS are input to a RAS buffer and a CAS buffer, an internal RAS and an internal CAS are generated. The internal RAS is input to a clock generating circuit and a CBR mode determination circuit and the internal CAS is input to the CBR mode determination circuit. The clock generating circuit outputs a pump clock to first and second WL pumps upon input of internal RAS, and the first WL pump supplies charge to a Vpp power supply. If CAS is input prior to RAS during refresh operation, CBR mode determination circuit inputs a CBR mode signal to the second WL pump which supplies charge to Vpp power supply together with the first WL pump when the pump clock and the CBR mode signal is input thereto.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: December 16, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Kiyohiro Furutani, Yoshikazu Morooka
  • Patent number: 5698869
    Abstract: A structure of a semiconductor device and a method of manufacturing the same is provided wherein a leakage current can be reduced while improving a drain breakdown voltage of an Insulated-Gate transistor such as a MOSFET, MOSSIT and a MISFET, and a holding characteristic of a memory cell such as a DRAM using these transistors as switching transistors can be improved, and further a reliability of a gate oxide film in a transfer gate can be improved. More particularly, a narrow band gap semiconductor region such as Si.sub.x Ge.sub.1-x, Si.sub.x Sn.sub.1-x, PbS is formed in an interior of a source region or a drain region in the SOI.IG-device. By selecting location and/or mole fraction of the narrow band gap semiconductor region in a SOI film, or selecting a kind of impurity element to compensate the crystal lattice mismatching due to the narrow-bandgap semiconductor region, the generation of crystal defects can be suppressed.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: December 16, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Makoto Yoshimi, Satoshi Inaba, Atsushi Murakoshi, Mamoru Terauchi, Naoyuki Shigyo, Yoshiaki Matsushita, Masami Aoki, Takeshi Hamamoto, Yutaka Ishibashi, Tohru Ozaki, Hitomi Kawaguchiya, Kazuya Matsuzawa, Osamu Arisumi, Akira Nishiyama
  • Patent number: 5672891
    Abstract: A semiconductor memory device comprises a semiconductor substrate having memory cell area, a plurality of trenches selectively formed in the memory cell area aligning in certain intervals and a plurality of memory cell arrays provided in the memory cell area, wherein each of the memory cell arrays comprises a plurality of MOS transistors connected in a serial array and a plurality of capacitors each formed in a corresponding one of the trenches. Each of the transistors has a gate electrode above the substrate with a gate insulating film formed therebetween and source and drain regions formed in the substrate on both sides of the gate electrode.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: September 30, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Takashi Yamada, Yutaka Ishibashi
  • Patent number: 5561311
    Abstract: A semiconductor memory having memory cells is formed on a semiconductor substrate. Each of the memory cells has a transistor and a capacitor. The transistor includes a channel region, a drain region and a source region aligned in a line and being insulated by an insulation film from an adjacent cell. Each of the memory cells has a gate electrode formed on the channel region with a gate insulating film therebetween. A pad electrode makes electrical contact with one of the source and drain regions of the memory cell and extends over the insulation film. A bit line makes electrical contact with the pad electrode above, extends in parallel to the line and is laterally isolated from one of the source and drain regions. A first insulating film is formed on the semiconductor substrate over the bit line.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: October 1, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Fumio Horiguchi, Katsuhiko Hieda
  • Patent number: 5548145
    Abstract: A semiconductor memory device comprises a semiconductor substrate having memory cell area, a plurality of trenches selectively formed in the memory cell area aligning in certain intervals and a plurality of memory cell arrays provided in the memory cell area, wherein each of the memory cell arrays comprises a plurality of MOS transistors connected in a serial array and a plurality of capacitors each formed in a corresponding one of the trenches. Each of the transistors has a gate electrode above the substrate with a gate insulating film formed therebetween and source and drain regions formed in the substrate on both sides of the gate electrode.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: August 20, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Takashi Yamada, Yutaka Ishibashi
  • Patent number: 5508541
    Abstract: A MOS random access memory device includes a semiconductor substrate having a trench formed therein, and an array of memory cells on the substrate. Each of the memory cells includes a 1-bit data-storage capacitor and a transfer-gate MOS transistor. The capacitor includes an insulated layer buried in the trench, which serves as a storage node. An island-shaped semiconductor layer covers the storage-node layer at least partially on the substrate, and is coupled thereto. The transistor has a source and a drain defining a channel region therebetween in the substrate, and an insulated gate overlying the channel region. One of the source and drain is directly coupled to the island-shaped layer, while the other of them is contacted with a corresponding data-transfer line (bit line) associated therewith.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: April 16, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Hieda, Masami Aoki, Takeshi Hamamoto
  • Patent number: 5481496
    Abstract: Sense amplifiers provided for each of the bit line pairs are divided into groups to be independently driven, whereby the influence of sense amplifiers of different groups can be prevented, and therefore the destruction of data of the non-selected memory cells during data transfer can be prevented. In transferring data from the data register to the memory cell array, the sense amplifier is not activated until the stored information of the memory cells selected by the word line is fully read to the corresponding bit lines, whereby the destruction of data stored in the non-selected memory cells can be prevented.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: January 2, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshifumi Kobayashi, Yoshikazu Morooka, Michihiro Yamada, Takeshi Hamamoto
  • Patent number: 5477071
    Abstract: A random access memory device includes a semiconductive substrate having a surface in which a groove pattern is formed to provide a plurality of rows and columns of island portions. A plurality of trenches are formed in the island portions, which are provided with an array of memory cells arranged in rows and columns. Each of these memory cells consists of a capacitor and a metal oxide semiconductor (MOS) transistor which are stacked on each other in a corresponding one of the trenches. Parallel word lines are coupled to the rows of memory cells, and parallel bit lines are coupled to the columns of memory cells. An insulative layer is buried in each groove for causing adjacent ones of the island portions to be electrically isolated from each other.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: December 19, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Fumio Horiguchi
  • Patent number: 5448713
    Abstract: A device for executing fuzzy inference includes a first storage area constituting a condition portion of a fuzzy set and a second storage area constituting a conclusion portion of the fuzzy set. The first storage area stores membership functions of the condition portion in order to develop a first bit mapping while the second storage area stores membership functions of the conclusion portion in order to develop a second bit mapping. Each of the first and second storage areas has X addresses which are designated by an input signal and Y addresses which are designated by a membership value.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: September 5, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeshi Hamamoto
  • Patent number: 5418923
    Abstract: An encoding circuit shortens time required for a coincidence signal to be converted into an address code after selected and output sequentially according to a predetermined priority level when the coincidence signal is obtained from an associative memory. The circuit is provided with a contention arbitrating circuit for a lower subgroup and a contention arbitrating circuit for a higher subgroup. In the contention arbitrating circuit for a lower subgroup and the contention arbitrating circuit for higher subgroup, each coincidence signal simultaneously activates inhibiting signals whose priority levels are lower than the priority level of the coincidence signal. A lower half of coincidence signals are arranged in descending order in the contention arbitrating circuit for a lower subgroup and a higher half of coincidence signals are arranged in ascending order in the contention arbitrating circuit for a higher subgroup.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: May 23, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masaaki Mihara, Tadato Yamagata, Takeshi Hamamoto
  • Patent number: 5387532
    Abstract: A semiconductor memory has many memory cells of which each has a transistor and a capacitor. In each memory cell, one of source and drain regions of the transistor is connected to a bit line formed above the transistor. The capacitor includes a first capacitor electrode formed on a substrate and a second capacitor electrode formed on an insulation film coated on the surface of the first capacitor electrode. The first capacitor electrode is connected to the other of the source and drain regions of the transistor. The first capacitor electrode is formed above the bit line.To manufacture such a semiconductor memory, each memory cell region is separately formed on the surface of a substrate. A gate insulation film is formed on the memory cell region. A gate electrode is formed on the gate insulation film. The gate electrode is used as a mask to dope the substrate with impurities to form source and drain regions of a transistor. A bit line is formed and connected to one of the source and drain regions.
    Type: Grant
    Filed: August 10, 1993
    Date of Patent: February 7, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeshi Hamamoto, Fumio Horiguchi, Katsuhiko Hieda
  • Patent number: 5388066
    Abstract: A data storing circuit including memory cells arranged in a plurality of rows and columns and flag cells corresponding to respective rows for storing flag information, the memory cells and the flag cell of the same row constituting one word, is provided. When a retrieval data is externally applied, the data included in the retrieval data is compared with the data of the memory cell, and the flag information stored in the retrieval data is compared with the flag stored in the flag cell. Respective results of comparison are output to a match line. Logical operation circuit carries out logical operation dependent on the result of comparison output to the match line, and writes the logical output to the flag cell of the data storing circuit.
    Type: Grant
    Filed: July 1, 1993
    Date of Patent: February 7, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Hamamoto, Tadato Yamagata, Masaaki Mihara