Patents by Inventor Kenichi Imamiya

Kenichi Imamiya 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: 8493814
    Abstract: A semiconductor memory device has a memory cell array, a first transistor of a first conductivity type, a second transistor of a second conductivity type and a third transistor of the first conductivity type. A source or drain of the first transistor is connected to each of word lines. A drain of the second transistor is connected to a gate of the first transistor. A source of the third transistor is connected to the gate of the first transistor. The gates of the second transistor and the third transistor are not connected, a source of the second transistor is not connected to a drain of the third transistor, and the gate of the second transistor and the drain of the third transistor have different voltage levels corresponding to opposite logic levels each other.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: July 23, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Patent number: 8477541
    Abstract: In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
    Type: Grant
    Filed: June 6, 2012
    Date of Patent: July 2, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Toshio Yamamura, Koji Hosono, Koichi Kawai
  • Patent number: 8472268
    Abstract: A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: June 25, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Hiroshi Nakamura, Ken Takeuchi, Kenichi Imamiya
  • Publication number: 20130088922
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Application
    Filed: November 23, 2012
    Publication date: April 11, 2013
    Inventors: Hiroshi NAKAMURA, Kenichi Imamiya, Ken Takeuchi
  • Patent number: 8406056
    Abstract: A memory cell array has a structure in which a plurality of memory cells connected with word lines and bit lines and connected in series are arranged in a matrix form. A selection transistor selects the word lines. A control circuit controls potentials of the word lines and the bit lines in accordance with input data, and controls write, read and erase operations of data with respect to the memory cell. The selection transistor is formed on a well, and a first negative voltage is supplied to a well, a first voltage (the first voltage the first negative voltage) is supplied to a selected word line and a second voltage is supplied to a non-selected word line in the read operation.
    Type: Grant
    Filed: December 19, 2011
    Date of Patent: March 26, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Noboru Shibata, Kenichi Imamiya
  • Patent number: 8350309
    Abstract: A select gate transistor has a select gate electrode composed of a first-level conductive layer and a second-level conductive layer. The first-level conductive layer has contact areas. The second-level conductive layer has its portions removed that are located above the contact areas. Two adjacent select gate electrodes that are adjacent to each other in the column direction are arranged such that the contact areas of one select gate electrode are not opposed to the contact areas of the other select gate electrode. One select gate electrode has its first- and second-level conductive layers removed in their portions that are opposed to the contact areas of the other select gate electrode.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: January 8, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Watanabe, Hiroshi Nakamura, Kazuhiro Shimizu, Seiichi Aritome, Toshitake Yaegashi, Yuji Takeuchi, Kenichi Imamiya, Ken Takeuchi, Hideko Oodaira
  • Publication number: 20120314497
    Abstract: A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.
    Type: Application
    Filed: August 20, 2012
    Publication date: December 13, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Nakamura, Ken Takeuchi, Hideko Oodaira, Kenichi Imamiya, Kazuhito Narita, Kazuhiro Shimizu, Seiichi Aritome
  • Patent number: 8331124
    Abstract: One package contains a plurality of memory chips. Each memory chip has an I/O terminal which generates a busy signal. The busy signal enables a busy state when a power supply voltage value reaches a specified and guaranteed range after a power-on sequence. The busy signal maintains the busy state until completion of initialization operations for the plurality of memory chips. The busy signal releases the busy state after completion of all initialization operations for the plurality of memory chips.
    Type: Grant
    Filed: March 25, 2011
    Date of Patent: December 11, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Ken Takeuchi
  • Publication number: 20120243322
    Abstract: In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
    Type: Application
    Filed: June 6, 2012
    Publication date: September 27, 2012
    Inventors: Hiroshi NAKAMURA, Kenichi Imamiya, Toshio Yamamura, Koji Hosono, Koichi Kawai
  • Patent number: 8259494
    Abstract: A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having a plurality of memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.
    Type: Grant
    Filed: August 12, 2010
    Date of Patent: September 4, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Ken Takeuchi, Hideko Oodaira, Kenichi Imamiya, Kazuhito Narita, Kazuhiro Shimizu, Seiichi Aritome
  • Patent number: 8248849
    Abstract: A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having a plurality of memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.
    Type: Grant
    Filed: August 12, 2010
    Date of Patent: August 21, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Ken Takeuchi, Hideko Oodaira, Kenichi Imamiya, Kazuhito Narita, Kazuhiro Shimizu, Seiichi Aritome
  • Publication number: 20120182798
    Abstract: A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range.
    Type: Application
    Filed: March 23, 2012
    Publication date: July 19, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koji Hosono, Hiroshi Nakamura, Ken Takeuchi, Kenichi Imamiya
  • Patent number: 8218374
    Abstract: In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: July 10, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Toshio Yamamura, Koji Hosono, Koichi Kawai
  • Patent number: 8218373
    Abstract: In a semiconductor integrated circuit, an internal circuit is capable of executing a first operation and a second operation concurrently, and an output circuit outputs to the outside of the semiconductor integrated circuit information indicating whether or not the first operation is being executed and information indicating whether or not the second operation is executable.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: July 10, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya, Toshio Yamamura, Koji Hosono, Koichi Kawai
  • Publication number: 20120147673
    Abstract: A semiconductor memory device has a memory cell array, a first transistor of a first conductivity type, a second transistor of a second conductivity type and a third transistor of the first conductivity type. A source or drain of the first transistor is connected to each of word lines. A drain of the second transistor is connected to a gate of the first transistor. A source of the third transistor is connected to the gate of the first transistor. The gates of the second transistor and the third transistor are not connected, a source of the second transistor is not connected to a drain of the third transistor, and the gate of the second transistor and the drain of the third transistor have different voltage levels corresponding to opposite logic levels each other.
    Type: Application
    Filed: February 14, 2012
    Publication date: June 14, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Nakamura, Kenichi Imamiya
  • Publication number: 20120140570
    Abstract: In an EEPROM consisting of a NAND cell in which a plurality of memory cells are connected in series, the control gate voltage Vread of the memory cell in a block selected by the data read operation is made different from the each of the voltages Vsg1, Vsg2 of the select gate of the select transistor in the selected block so as to make it possible to achieve a high speed reading without bringing about the breakdown of the insulating film interposed between the select gate and the channel of the select transistor. The high speed reading can also be made possible in the DINOR cell, the AND cell, NOR cell and the NAND cell having a single memory cell connected thereto, if the control gate voltage of the memory cell is made different from the voltage of the select gate of the select transistor.
    Type: Application
    Filed: February 9, 2012
    Publication date: June 7, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi NAKAMURA, Kenichi IMAMIYA
  • Publication number: 20120092929
    Abstract: A memory cell array has a structure in which a plurality of memory cells connected with word lines and bit lines and connected in series are arranged in a matrix form. A selection transistor selects the word lines. A control circuit controls potentials of the word lines and the bit lines in accordance with input data, and controls write, read and erase operations of data with respect to the memory cell. The selection transistor is formed on a well, and a first negative voltage is supplied to a well, a first voltage (the first voltage the first negative voltage) is supplied to a selected word line and a second voltage is supplied to a non-selected word line in the read operation.
    Type: Application
    Filed: December 19, 2011
    Publication date: April 19, 2012
    Inventors: Noboru Shibata, Kenichi Imamiya
  • Publication number: 20120075903
    Abstract: A select gate transistor has a select gate electrode composed of a first-level conductive layer and a second-level conductive layer. The first-level conductive layer has contact areas. The second-level conductive layer has its portions removed that are located above the contact areas. Two adjacent select gate electrodes that are adjacent to each other in the column direction are arranged such that the contact areas of one select gate electrode are not opposed to the contact areas of the other select gate electrode. One select gate electrode has its first- and second-level conductive layers removed in their portions that are opposed to the contact areas of the other select gate electrode.
    Type: Application
    Filed: December 2, 2011
    Publication date: March 29, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hiroshi Watanabe, Hiroshi Nakamura, Kazuhiro Shimizu, Seiichi Aritome, Toshitake Yaegashi, Yuji Takeuchi, Kenichi Imamiya, Ken Takeuchi, Hideko Oodaira
  • Patent number: 8144513
    Abstract: A non-volatile semiconductor device has a memory cell array having electrically erasable programmable non-volatile memory cells, reprogramming and retrieval circuits that temporarily store data to be programmed in the memory cell array and sense data retrieved from the memory cell array. Each reprogramming and retrieval circuit has first and second latches that are selectively connected to the memory cell array and transfer data. A controller controls the reprogramming and retrieval circuits on a data-reprogramming operation to and a data-retrieval operation from the memory cell array. Each reprogramming and retrieval circuit has a multilevel logical operation mode and a caching operation mode. In the multilevel logical operation mode, re-programming and retrieval of upper and lower bits of two-bit four-level data is performed using the first and the second latches to store the two-bit four-level data in one of the memory cells in a predetermined threshold level range.
    Type: Grant
    Filed: December 6, 2010
    Date of Patent: March 27, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Hiroshi Nakamura, Ken Takeuchi, Kenichi Imamiya
  • Patent number: 8129774
    Abstract: In an EEPROM consisting of a NAND cell in which a plurality of memory cells are connected in series, the control gate voltage Vread of the memory cell in a block selected by the data read operation is made different from the each of the voltages Vsg1, Vsg2 of the select gate of the select transistor in the selected block so as to make it possible to achieve a high speed reading without bringing about the breakdown of the insulating film interposed between the select gate and the channel of the select transistor. The high speed reading can also be made possible in the DINOR cell, the AND cell, NOR cell and the NAND cell having a single memory cell connected thereto, if the control gate voltage of the memory cell is made different from the voltage of the select gate of the select transistor.
    Type: Grant
    Filed: July 9, 2010
    Date of Patent: March 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Nakamura, Kenichi Imamiya