Patents by Inventor Tsutomu Nakai

Tsutomu Nakai 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: 8423705
    Abstract: A semiconductor device includes a first nonvolatile storage area including a plurality of sectors, a second nonvolatile storage area, a third nonvolatile storage area located in the first nonvolatile storage area, a fourth nonvolatile storage area located in the second nonvolatile storage area, and a control portion selecting one of a first mode and a second mode. In first mode, sectors where the third nonvolatile storage area is not located in the first nonvolatile storage area are used as a main storage area, and the second nonvolatile storage area is used to store a program or data that is read before the first nonvolatile storage area is accessed, the third nonvolatile storage area being used to store control information that controls writing, reading, and erasing of data involved in the first nonvolatile storage area or the second nonvolatile storage area.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: April 16, 2013
    Assignee: Spansion LLC
    Inventors: Hirokazu Nagashima, Kazuki Yamauchi, Junya Kawamata, Tsutomu Nakai, Kenji Arai, Kenichi Takehana
  • Patent number: 7787312
    Abstract: A semiconductor device has a plurality of bit lines BL provided in a memory cell area 101, a plurality of word lines WL provided crossing the plurality of bit lines BL, a plurality of diffusion source lines VSL provided along the plurality of word lines WL, a plurality of non-volatile active cells AC storing data, the plurality of non-volatile active cells AC being provided at cross sections of the plurality of bit lines BL and the plurality of word lines WL and being connected to the plurality of bit lines BL, the plurality of word lines WL, and the plurality of diffusion source lines VSL, and a controller simultaneously writes or reads data to and from at least two active cells AC among the plurality of active cells AC, in which the number of the plurality of active cells AC is less than that of the cross sections.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: August 31, 2010
    Assignee: Spansion LLC
    Inventors: Junya Kawamata, Tsutomu Nakai, Hirokazu Nagashima, Kenichi Takehana, Kenji Arai, Kazuki Yamauchi, Kazuhide Kurosaki
  • Patent number: 7679968
    Abstract: Structures, methods, and systems for enhanced erasing operation for non-volatile memory are disclosed. In one embodiment, a semiconductor device which comprises a memory cell array having a plurality of non-volatile memory cells, a negative voltage generating circuit for applying a negative voltage to a word line of the memory cell array during an erasing operation of the memory cell array, and a positive voltage generating circuit for applying a positive voltage to a well of the memory cell array when the negative voltage reaches a predetermined voltage.
    Type: Grant
    Filed: May 29, 2008
    Date of Patent: March 16, 2010
    Assignee: Spansion LLC
    Inventors: Kazuki Yamauchi, Junya Kawamata, Tsutomu Nakai, Kenji Arai, Hirokazu Nagashima, Kenichi Takehana
  • Publication number: 20090010076
    Abstract: A semiconductor device has a plurality of bit lines BL provided in a memory cell area 101, a plurality of word lines WL provided crossing the plurality of bit lines BL, a plurality of diffusion source lines VSL provided along the plurality of word lines WL, a plurality of non-volatile active cells AC storing data, the plurality of non-volatile active cells AC being provided at cross sections of the plurality of bit lines BL and the plurality of word lines WL and being connected to the plurality of bit lines BL, the plurality of word lines WL, and the plurality of diffusion source lines VSL, and a controller simultaneously writes or reads data to and from at least two active cells AC among the plurality of active cells AC, in which the number of the plurality of active cells AC is less than that of the cross sections.
    Type: Application
    Filed: May 30, 2008
    Publication date: January 8, 2009
    Applicant: SPANSION LLC
    Inventors: Junya Kawamata, Tsutomu Nakai, Hirokazu Nagashima, Kenichi Takehana, Kenji Arai, Kazuki Yamauchi, Kazuhide Kurosaki
  • Publication number: 20080320208
    Abstract: A semiconductor device includes a first nonvolatile storage area including a plurality of sectors, a second nonvolatile storage area, a third nonvolatile storage area located in the first nonvolatile storage area, a fourth nonvolatile storage area located in the second nonvolatile storage area, and a control portion selecting one of a first mode and a second mode. In first mode, sectors where the third nonvolatile storage area is not located in the first nonvolatile storage area are used as a main storage area, and the second nonvolatile storage area is used to store a program or data that is read before the first nonvolatile storage area is accessed, the third nonvolatile storage area being used to store control information that controls writing, reading, and erasing of data involved in the first nonvolatile storage area or the second nonvolatile storage area.
    Type: Application
    Filed: June 13, 2008
    Publication date: December 25, 2008
    Applicant: SPANSION LLC
    Inventors: Hirokazu Nagashima, Kazuki Yamauchi, Junya Kawamata, Tsutomu Nakai, Kenji Arai, Kenichi Takehana
  • Patent number: 7462529
    Abstract: A semiconductor nonvolatile memory device for storing multi-bit data has a memory cell having a source region S and a drain region D formed at the surface of a semiconductor substrate, a gate insulator film and a control gate CG formed on a channel region CH between the source region S and the drain region D and a nonconductive trap gate in the gate insulator film. An indentation is provided at the surface of the semiconductor substrate covering a region from a position in the vicinity of the drain region in the channel region to the drain region. By providing the indentation on the drain region side of the channel region, the trap gate is positioned in the direction of a channel current flowing from the source region S to the drain region D. Then, a charge having run through the channel region CH is injected efficiently into the trap gate on the indentation.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: December 9, 2008
    Assignee: Spansion LLC
    Inventor: Tsutomu Nakai
  • Publication number: 20080298136
    Abstract: Structures, methods, and systems for enhanced erasing operation for non-volatile memory are disclosed. In one embodiment, a semiconductor device which comprises a memory cell array having a plurality of non-volatile memory cells, a negative voltage generating circuit for applying a negative voltage to a word line of the memory cell array during an erasing operation of the memory cell array, and a positive voltage generating circuit for applying a positive voltage to a well of the memory cell array when the negative voltage reaches a predetermined voltage.
    Type: Application
    Filed: May 29, 2008
    Publication date: December 4, 2008
    Inventors: Kazuki Yamauchi, Junya Kawamata, Tsutomu Nakai, Kenji Arai, Hirokazu Nagashima, Kenichi Takehana
  • Patent number: 7450419
    Abstract: The present invention provides a semiconductor device and a method for controlling a semiconductor device having a memory cell array having a plurality of nonvolatile memory cells, the method including detecting the number of bits to be written as division data that is divided from data to be programmed into the memory cell array, comparing the number of bits with a predetermined number of bits, inverting or not inverting the division data to produce inversion data in accordance with a result of comparing the number of bits with the predetermined number of bits, and programming the inversion data into the memory cell array. The method further includes detecting the number of bits to be written as next division data and comparing the number of bits of next division data with the predetermined number of bits, while concurrently programming the inversion data into the memory cell array.
    Type: Grant
    Filed: December 7, 2006
    Date of Patent: November 11, 2008
    Assignee: Spansion LLC
    Inventors: Mototada Sakashita, Masaru Yano, Akira Ogawa, Tsutomu Nakai
  • Patent number: 7286407
    Abstract: A semiconductor device includes a program voltage supply circuit that supplies a drain of a memory cell with a program voltage, and a pull-down circuit that pulls down a potential of an output of the program voltage supply circuit in accordance with a current that flows in a data bus line connected to the memory cell. The semiconductor device may include a program voltage restrain circuit that restrains an intensity of supply of the program voltage by the program voltage supply circuit.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: October 23, 2007
    Assignee: Spansion LLC
    Inventors: Tsutomu Nakai, Kazuhide Kurosaki
  • Publication number: 20070180184
    Abstract: The present invention provides a semiconductor device and a method for controlling a semiconductor device having a memory cell array having a plurality of nonvolatile memory cells, the method including detecting the number of bits to be written as division data that is divided from data to be programmed into the memory cell array, comparing the number of bits with a predetermined number of bits, inverting or not inverting the division data to produce inversion data in accordance with a result of comparing the number of bits with the predetermined number of bits, and programming the inversion data into the memory cell array. The method further includes detecting the number of bits to be written as next division data and comparing the number of bits of next division data with the predetermined number of bits, while concurrently programming the inversion data into the memory cell array.
    Type: Application
    Filed: December 7, 2006
    Publication date: August 2, 2007
    Inventors: Mototada Sakashita, Masaru Yano, Akira Ogawa, Tsutomu Nakai
  • Patent number: 7221595
    Abstract: A semiconductor device includes a first cascode circuit having a first current mirror amplifying a reference current flowing through a data line of a reference cell, and a second current mirror generating a first potential from an amplified reference current; and a second cascode circuit having a third current mirror amplifying a core current flowing through a data line of a core cell, and a transistor receiving a gate voltage corresponding to the amplified reference current and generating a second potential based on a difference between an amplified core cell current and the amplified reference current. Since the second potential is generated by the difference between the core cell current and the reference cell current, the second potential swings in the full range of the ground power supply voltage to the ground potential, and the range of the amplitude of the power supply voltage can be efficiently utilized. Sensing is enabled for a fine current margin.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: May 22, 2007
    Assignee: Spansion LLC
    Inventors: Tsutomu Nakai, Takao Akaogi, Kazuhide Kurosaki
  • Publication number: 20060166449
    Abstract: A semiconductor nonvolatile memory device for storing multi-bit data has a memory cell having a source region S and a drain region D formed at the surface of a semiconductor substrate, a gate insulator film and a control gate CG formed on a channel region CH between the source region S and the drain region D and a nonconductive trap gate in the gate insulator film. An indentation is provided at the surface of the semiconductor substrate covering a region from a position in the vicinity of the drain region in the channel region to the drain region. By providing the indentation on the drain region side of the channel region, the trap gate is positioned in the direction of a channel current flowing from the source region S to the drain region D. Then, a charge having run through the channel region CH is injected efficiently into the trap gate on the indentation.
    Type: Application
    Filed: March 23, 2006
    Publication date: July 27, 2006
    Applicant: FUJITSU LIMITED
    Inventor: Tsutomu Nakai
  • Patent number: 7057229
    Abstract: A semiconductor nonvolatile memory device for storing multi-bit data has a memory cell having a source region S and a drain region D formed at the surface of a semiconductor substrate, a gate insulator film and a control gate CG formed on a channel region CH between the source region S and the drain region D and a nonconductive trap gate in the gate insulator film. An indentation 4 is provided at the surface of the semiconductor substrate covering a region from a position in the vicinity of the drain region in the channel region to the drain region. By providing the indentation 4 on the drain region side of the channel region, the trap gate is positioned in the direction of a channel current flowing from the source region S to the drain region D. Then, the a charge having run through the channel region CH is injected efficiently into the trap gate on the indentation.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: June 6, 2006
    Assignee: Fujitsu Limited
    Inventor: Tsutomu Nakai
  • Publication number: 20060092706
    Abstract: A semiconductor device includes a program voltage supply circuit that supplies a drain of a memory cell with a program voltage, and a pull-down circuit that pulls down a potential of an output of the program voltage supply circuit in accordance with a current that flows in a data bus line connected to the memory cell. The semiconductor device may include a program voltage restrain circuit that restrains an intensity of supply of the program voltage by the program voltage supply circuit.
    Type: Application
    Filed: October 28, 2005
    Publication date: May 4, 2006
    Inventors: Tsutomu Nakai, Kazuhide Kurosaki
  • Publication number: 20060023539
    Abstract: A semiconductor device includes a first cascode circuit having a first current mirror amplifying a reference current flowing through a data line of a reference cell, and a second current mirror generating a first potential from an amplified reference current; and a second cascode circuit having a third current mirror amplifying a core current flowing through a data line of a core cell, and a transistor receiving a gate voltage corresponding to the amplified reference current and generating a second potential based on a difference between an amplified core cell current and the amplified reference current. Since the second potential is generated by the difference between the core cell current and the reference cell current, the second potential swings in the full range of the ground power supply voltage to the ground potential, and the range of the amplitude of the power supply voltage can be efficiently utilized. Sensing is enabled for a fine current margin.
    Type: Application
    Filed: July 29, 2005
    Publication date: February 2, 2006
    Inventors: Tsutomu Nakai, Takao Akaogi, Kazuhide Kurosaki
  • Patent number: 6865133
    Abstract: A memory circuit has a plurality of blocks which further comprises a plurality of regular sectors and a spare sector, wherein each sector further comprises a plurality of memory cells, and when a regular sector in a first block is defective, this defective regular sector is replaced with a spare sector in a second block. And responding to an address to be supplied, the regular sector corresponding to the supplied address in the first block and the spare selector in the second block are selected simultaneously during a first period, and after the first period, selection of one of the regular sector and the spare sector is maintained according to the result of redundancy judgment on whether the supply address matches with the redundant address.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: March 8, 2005
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Tsukidate, Kazuhiro Kurihara, Yasushi Kasa, Tsutomu Nakai, Andy Cheung
  • Publication number: 20040109371
    Abstract: A memory circuit has a plurality of blocks which further comprises a plurality of regular sectors and a spare sector, wherein each sector further comprises a plurality of memory cells, and when a regular sector in a first block is defective, this defective regular sector is replaced with a spare sector in a second block. And responding to an address to be supplied, the regular sector corresponding to the supplied address in the first block and the spare selector in the second block are selected simultaneously during a first period, and after the first period, selection of one of the regular sector and the spare sector is maintained according to the result of redundancy judgment on whether the supply address matches with the redundant address.
    Type: Application
    Filed: September 2, 2003
    Publication date: June 10, 2004
    Inventors: Yoshihiro Tsukidate, Kazuhiro Kurihara, Yasushi Kasa, Tsutomu Nakai, Andy Cheung
  • Patent number: 6625071
    Abstract: A memory circuit capable of salvaging defective cells, comprises a plurality of memory blocks each having a plurality of memory cells, a region which stores a block address of defective memory block that has defective cell, and a comparator circuit which compares the block address that is an object of access with the block address of the defective memory block, and detects access to the defective memory block, wherein in case where the comparator circuit detects access to the defective memory block, this defective memory block is replaced by the memory block that has the uppermost address (or lowermost address) among the plurality of memory blocks. In case where a plurality of defective memory blocks are present, the defective memory blocks are replaced with substitutive memory blocks having block addresses in order from the uppermost bit (or lowermost bit).
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: September 23, 2003
    Assignee: Fujitsu Limited
    Inventors: Mitsutaka Ikeda, Tsutomu Nakai, Koji Yamashita, Toshiyuki Kurita
  • Publication number: 20030104665
    Abstract: The present invention provides a semiconductor nonvolatile memory device for storing multi-bit data comprising a memory cell having a source region S and a drain region D formed at the surface of a semiconductor substrate, a gate insulator film and a control gate CG formed on a channel region CH between the source region S and the drain region D and a nonconductive trap gate in the gate insulator film. Furthermore, an indentation 4 is provided at the surface of the semiconductor substrate covering a region from a position in the vicinity of the drain region in the channel region to the drain region. By providing the indentation 4 on the drain region side of the channel region, the trap gate is positioned in the direction of a channel current flowing from the source region S to the drain region D. Then, the a charge having run through the channel region CH is injected efficiently into the trap gate on the indentation.
    Type: Application
    Filed: January 14, 2003
    Publication date: June 5, 2003
    Applicant: Fujitsu Limited
    Inventor: Tsutomu Nakai
  • Publication number: 20020105840
    Abstract: A memory circuit capable of salvaging defective cells, comprises a plurality of memory blocks each having a plurality of memory cells, a region which stores a block address of defective memory block that has defective cell, and a comparator circuit which compares the block address that is an object of access with the block address of the defective memory block, and detects access to the defective memory block, wherein in case where the comparator circuit detects access to the defective memory block, this defective memory block is replaced by the memory block that has the uppermost address (or lowermost address) among the plurality of memory blocks. In case where a plurality of defective memory blocks are present, the defective memory blocks are replaced with substitutive memory blocks having block addresses in order from the uppermost bit (or lowermost bit).
    Type: Application
    Filed: March 1, 2002
    Publication date: August 8, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Mitsutaka Ikeda, Tsutomu Nakai, Koji Yamashita, Toshiyuki Kurita