Patents by Inventor Susumu Shuto

Susumu Shuto 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: 20120153414
    Abstract: A semiconductor memory device according to an embodiment includes: a plurality of magnetic tunnel junction elements arranged on a semiconductor substrate; and a plurality of selection transistors electrically connected to first ends of the plurality of magnetic tunnel junction elements. A plurality of first bit lines are respectively connected to the first ends of the magnetic tunnel junction elements via one or more of the selection transistors. A plurality of upper electrodes are respectively connected to second ends of the plurality of magnetic tunnel junction elements. A plurality of second bit lines are respectively connected to the second ends of the magnetic tunnel junction elements via the upper electrodes. The upper electrodes extend along the second bit lines, and one of the upper electrodes is commonly connected to the second ends of the plurality of magnetic tunnel junction elements arranged in an extending direction of the second bit lines.
    Type: Application
    Filed: September 12, 2011
    Publication date: June 21, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu Shuto
  • Patent number: 8129766
    Abstract: A memory includes first contact plugs; ferroelectric capacitors above the first contact plugs; second contact plugs in a first interlayer film being below an area which is between two adjacent ferroelectric capacitors, the second contact plug; first interconnections connected to the second contact plugs, the first interconnections extending in a first direction substantially perpendicular to an arrangement direction, in which the two ferroelectric capacitors are arranged, on the first interlayer film; a second interlayer film above the first interlayer film and the first interconnection; third contact plugs in the second interlayer film, the third contact plugs being respectively connected to the first interconnections at positions shifted from the second contact plugs in the first direction; and second interconnections electrically connecting the third contact plug to the upper electrodes of the two ferroelectric capacitors.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: March 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Susumu Shuto
  • Publication number: 20110266600
    Abstract: A semiconductor memory device according to embodiments includes a semiconductor substrate and plural switching transistors provided on the semiconductor substrate. In the semiconductor memory device, a contact plug is embedded between adjacent two of the switching transistors, and is insulated from gates of the adjacent two switching transistors. The contact plug is also electrically connected to a source or a drain of each of the adjacent two switching transistors, and an upper surface of the contact plug is at a position higher than an upper surface of the switching transistors. A memory element is provided on the upper surface of the contact plug and stores data. A wiring is provided on the memory element.
    Type: Application
    Filed: February 22, 2011
    Publication date: November 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroyuki Kanaya, Yukinori Koyama, Susumu Shuto, Kuniaki Sugiura
  • Publication number: 20110018043
    Abstract: A memory includes first contact plugs; ferroelectric capacitors above the first contact plugs; second contact plugs in a first interlayer film being below an area which is between two adjacent ferroelectric capacitors, the second contact plug; first interconnections connected to the second contact plugs, the first interconnections extending in a first direction substantially perpendicular to an arrangement direction, in which the two ferroelectric capacitors are arranged, on the first interlayer film; a second interlayer film above the first interlayer film and the first interconnection; third contact plugs in the second interlayer film, the third contact plugs being respectively connected to the first interconnections at positions shifted from the second contact plugs in the first direction; and second interconnections electrically connecting the third contact plug to the upper electrodes of the two ferroelectric capacitors.
    Type: Application
    Filed: September 18, 2009
    Publication date: January 27, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu Shuto
  • Publication number: 20100073986
    Abstract: A semiconductor memory device includes a plurality of cell blocks each of which is configured by serially connecting a plurality of memory cells each of which comprises a ferroelectric capacitor and a cell transistor connected in parallel; a plurality of word lines connected to gates of the cell transistors; a plurality of block selectors each of which comprises an enhancement transistor and a depletion transistor serially connected to each other; a plurality of bit lines connected via the block selectors to one ends of the cell blocks; and a plurality of plate lines connected to the other ends of the cell blocks, wherein a gate length of the enhancement transistor is longer than that of the depletion transistor.
    Type: Application
    Filed: September 3, 2009
    Publication date: March 25, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu SHUTO
  • Patent number: 7663905
    Abstract: A ferroelectric memory device includes a memory cell, read circuit, temperature sensing circuit, and read controller. The memory cell includes a ferroelectric capacitor. The read circuit is configured to read data from the memory cell. The temperature sensing circuit is configured to sense the ambient temperature of the memory cell. The read controller is configured to receive a temperature sensing signal from the temperature sensing circuit, and inhibit a data read operation by the read circuit when the temperature sensed by the temperature sensing circuit is higher than a preset temperature.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: February 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Susumu Shuto
  • Publication number: 20100020588
    Abstract: A semiconductor memory device includes cell blocks configured to have a plurality of memory cells connected in series, each memory cell comprising a ferroelectric capacitor and a cell transistor connected in parallel with each other; word lines connected to gates of a plurality of the cell transistors; block selectors connected to first ends of the cell blocks; bit lines connected to the first ends of the cell blocks via the block selectors; and plate lines connected to second ends of the cell blocks, wherein the first ends of first and second cell blocks of the cell blocks respectively sharing the word lines are connected to the same bit line via the block selectors different from each other, and the second ends of the first and the second cell blocks respectively are connected to the plate lines different from each other.
    Type: Application
    Filed: July 24, 2009
    Publication date: January 28, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu SHUTO
  • Publication number: 20090219748
    Abstract: A ferroelectric memory includes ferroelectric capacitors including ferroelectric films between first electrodes and second electrodes; cell transistors; and a bit line contact connecting the cell transistors to a bit line, wherein the first electrode is connected to one of source and drain of the cell transistor at a first node, so that the ferroelectric capacitor and the cell transistor form a unit cell, the other of source and drain of the cell transistor for the unit cell is connected to the first node of other unit cell to serially connect the cell transistors for unit cells, so that the unit cells form a cell string, the word lines are connected to gates of the cell transistors or function as gates, the plate lines are connected to the second electrodes of the ferroelectric capacitors, and the bit line is connected to a cell transistor at an end of the cell string.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 3, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu SHUTO
  • Patent number: 7551472
    Abstract: A memory cell includes a ferroelectric capacitor for holding a charge and a transistor connected in parallel with the ferroelectric capacitor. A plurality of the ferroelectric memory cells are connected in series to form a memory cell block. A selection transistor connects, to one end of the block. A bit line connects to the selection transistor. A plate line connects to the other end of the block. A control circuit changes potentials of the word line and the bit line. With the potential of the plate line being held constant, the potential of the word line is changed, thereby erasing information or writing information to the ferroelectric memory cells.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: June 23, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Susumu Shuto
  • Patent number: 7535745
    Abstract: A ferroelectric memory device, which includes a vertical ferroelectric capacitor having an electrode distance smaller than a minimum feature size of lithography technology being used and suitable for the miniaturization, and a method of manufacturing the same are disclosed. According to one aspect of the present invention, it is provided a ferroelectric memory device comprising an MIS transistor formed on a substrate, and a ferroelectric capacitor formed on an interlevel insulator above the MIS transistor, wherein a pair of electrodes of the ferroelectric capacitor are disposed in a channel length direction of the MIS transistor to face each other putting a ferroelectric film in-between, and wherein a distance between the electrodes of the ferroelectric capacitor is smaller than a gate length of the MIS transistor.
    Type: Grant
    Filed: June 19, 2006
    Date of Patent: May 19, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Susumu Shuto
  • Publication number: 20090059648
    Abstract: This ferroelectric semiconductor storage device includes: a ferroelectric capacitor; and a transistor having one end of its current path connected to one electrode of the ferroelectric capacitor. A plate line is connected to the other electrode of the ferroelectric capacitor. A word line is connected to the gate of the transistor. A bit line is connected to the other electrode of a capacitor and the other end of the transistor, the capacitor having its one electrode connected to the ground. A bit line potential detection circuit detects a potential of the bit line. A connection circuit provides the same potential between a potential of the plate line and a potential of the bit line based on an output from the bit line potential detection circuit.
    Type: Application
    Filed: August 29, 2008
    Publication date: March 5, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu SHUTO
  • Patent number: 7436691
    Abstract: A semiconductor storage device includes a bit line; a word line; a plate line; a ferroelectric capacitor having a ferroelectric substance between electrodes, one of the electrodes being connected to the plate line, the ferroelectric capacitor being capable of storing data; a selection transistor connected between the other of the electrodes of the ferroelectric capacitor and the bit line, the selection transistor being capable of selectively connecting the ferroelectric capacitor to the bit line on the basis of a potential on the word line; a bit line driver corresponding to the bit line to drive the bit line; a word line driver corresponding to the word line to drive the word line; and a plate line driver corresponding to the plate line, the plate line driver including a plurality of plate voltage lines so as to be able to apply a plurality of different voltage values to the plate line, the plate line driver connecting a common single plate voltage line included in the plate voltage lines to the plate line w
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: October 14, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuki Yamada, Susumu Shuto
  • Publication number: 20080219038
    Abstract: Disclosed is a ferroelectric memory device. Multiple memory cells are connected between bit lines and a plate line, and constitute a memory cell array. Each of the memory cells is composed of a first ferroelectric capacitor and a memory cell transistor. The gates of the memory cell transistors are connected to multiple word lines, respectively. The bit lines are connected to multiple sense amplifiers for amplifying information. One end of the second ferroelectric capacitor is electrically connected to a corresponding one of the bit lines, and the other end of the second ferroelectric capacitor is electrically connected to a power supply.
    Type: Application
    Filed: March 5, 2008
    Publication date: September 11, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Susumu SHUTO
  • Patent number: 7417274
    Abstract: A semiconductor device comprises an insulation film that is provided on a semiconductor substrate, a first contact plug that is provided in the insulation film and includes a metal, a first adhesive film that is provided on the insulation film, has a higher oxygen affinity than the metal, and includes an oxide, a second adhesive film that is provided on the first contact plug and has a film thickness that is smaller than a film thickness of the first adhesive film, a first capacitor electrode that is provided on the contact plug and the first adhesive film, has a part in direct contact with the first contact plug, a capacitor insulation film that is provided on the first capacitor electrode, and a second capacitor electrode that is provided on the capacitor insulation film.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: August 26, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tohru Ozaki, Yoshinori Kumura, Yoshiro Shimojo, Susumu Shuto
  • Publication number: 20080173912
    Abstract: A semiconductor device comprising a ferroelectric capacitor having improved reliability is disclosed. According to one aspect of the present invention, it is provided a semiconductor device comprising a transistor formed on a semiconductor substrate, a ferroelectric capacitor formed above the transistor and comprising a lower electrode, a ferroelectric film and an upper electrode, a first hydrogen barrier film formed over the ferroelectric capacitor, an insulator formed over the first hydrogen barrier film, a contact plug disposed in the insulator and electrically connected with the upper electrode, a second hydrogen barrier film disposed between the contact plug and the insulator continuously, and a wiring connected with the contact plug.
    Type: Application
    Filed: November 16, 2007
    Publication date: July 24, 2008
    Inventors: Yoshinori KUMURA, Tohru Ozaki, Susumu Shuto, Yoshiro Shimojo, Iwao Kunishima
  • Publication number: 20080135901
    Abstract: A semiconductor memory, comprising: a first memory cell transistor disposed on a semiconductor substrate; a second memory cell transistor disposed on the semiconductor substrate and having a first source-drain region in common with the first memory cell transistor; a first ferroelectric capacitor disposed with a via in between above a second source-drain region of the first memory cell transistor; a second ferroelectric capacitor disposed with a via in between above a second source-drain region of the second memory cell transistor; an interlayer dielectric disposed on the semiconductor substrate, as coating the memory cell transistors and the ferroelectric capacitors, the interlayer dielectric having a contact hole through which the first source-drain region is partially exposed at the bottom and upper electrodes of the first and second ferroelectric capacitors are partially exposed at the top; and a wiring layer filled into the contact hole, which connects the first source-drain region, the upper electrode o
    Type: Application
    Filed: November 14, 2007
    Publication date: June 12, 2008
    Inventors: Yoshiro SHIMOJO, Susumu Shuto, Iwao Kunishima, Tohru Ozaki
  • Publication number: 20080121954
    Abstract: A ferroelectric layer is formed on a semiconductor substrate, a first hard mask layer is formed on the ferroelectric layer, and a second hard mask layer is formed on the first hard mask layer. A plurality of parallel isolation trenches are formed by etching the second hard mask layer, first hard mask layer, and ferroelectric layer in a direction perpendicular to the major surface of the substrate. Electrode layers are formed on the sidewalls of the ferroelectric layer which face the trenches and on the second hard mask layer.
    Type: Application
    Filed: November 24, 2006
    Publication date: May 29, 2008
    Inventor: Susumu SHUTO
  • Patent number: 7348617
    Abstract: A semiconductor device comprising a ferroelectric capacitor having improved reliability is disclosed. According to one aspect of the present invention, it is provided a semiconductor device comprising a transistor formed on a semiconductor substrate, a ferroelectric capacitor formed above the transistor and comprising a lower electrode, a ferroelectric film and an upper electrode, a first hydrogen barrier film formed over the ferroelectric capacitor, an insulator formed over the first hydrogen barrier film, a contact plug disposed in the insulator and electrically connected with the upper electrode, a second hydrogen barrier film disposed between the contact plug and the insulator continuously, and a wiring connected with the contact plug.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: March 25, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshinori Kumura, Tohru Ozaki, Susumu Shuto, Yoshiro Shimojo, Iwao Kunishima
  • Publication number: 20080055962
    Abstract: A memory cell includes a ferroelectric capacitor for holding a charge and a transistor connected in parallel with the ferroelectric capacitor. A plurality of the ferroelectric memory cells are connected in series to form a memory cell block. A selection transistor connects,to one end of the block. A bit line connects to the selection transistor. A plate line connects to the other end of the block. A control circuit changes potentials of the word line and the bit line. With the potential of the plate line being held constant, the potential of the word line is changed, thereby erasing information or writing information to the ferroelectric memory cells.
    Type: Application
    Filed: August 29, 2007
    Publication date: March 6, 2008
    Inventor: Susumu Shuto
  • Patent number: 7339828
    Abstract: A semiconductor device comprises a memory cell array and a source line driver. Each of the memory cells in the memory cell array has a floating gate cell transistor which stores data by accumulating charge in the floating gate and a select gate transistor whose drain is connected to the source of the cell transistor and whose source is connected to a source line. The source line driver is configured so as to drive the source line in a write operation at a potential between the substrate bias potential of the cell transistor and select gate transistor and the ground potential.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: March 4, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takehiro Hasegawa, Susumu Shuto