Patents by Inventor Akihide Shibata

Akihide Shibata 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: 7170791
    Abstract: A programming verification method of verifying programming of a nonvolatile memory cell, the method comprising at least the steps of: selecting first, second, . . . and n-th references corresponding to first, second, . . . and n-th threshold voltages specifying lower limit values of states 1, 2, . . .
    Type: Grant
    Filed: May 19, 2004
    Date of Patent: January 30, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuaki Iwase, Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Patent number: 7170789
    Abstract: Characteristic fluctuation of a reference cell due to read disturb is prevented. A memory cell 27m and a reference cell 27r respectively have memory function bodies that are formed on both sides of a gate electrode and have a function to retain electric charge or polarization. The memory cell 27m can store independent information pieces in memory function bodies 27mr and 27ml located on both sides of the gate electrode and the independent information pieces are read therefrom. On the other hand, in the reference cell 27r, only the information piece stored in a memory function body 27rl located on one side of the gate electrode is referred to in a sense amplifier 22.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: January 30, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Iwata, Yoshifumi Yaoi, Akihide Shibata
  • Patent number: 7167402
    Abstract: A semiconductor storage device includes a plurality of memory elements and a redundancy circuit. Each of the memory elements includes a gate electrode provided on a semiconductor layer, a gate insulating film intervening between the gate electrode and the semiconductor layer, a channel region provided under the gate electrode, diffusion regions respectively provided at both sides of the channel region, the diffusion regions having a conductivity type which is opposite a conductivity type of the channel region, and memory functioning members respectively provided at both sides of the gate electrode, the memory functioning members having a function of holding charge. The redundancy circuit addresses a single chip memory including cells associated with a plurality of redundant lines and includes a decoder for selecting a redundant row. The semiconductor storage device can permanently inactivate further programming of the redundancy circuit in order to prevent a user from performing inadvertent programming.
    Type: Grant
    Filed: May 19, 2004
    Date of Patent: January 23, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Patent number: 7164167
    Abstract: The present invention provides a semiconductor storage device having: a first conductivity type region formed in a semiconductor layer; a second conductivity type region formed in the semiconductor layer in contact with the first conductivity type region; a memory functional element disposed on the semiconductor layer across the boundary of the first and second conductivity type regions; and an electrode provided in contact with the memory functional element and on the first conductivity type region via an insulation film, and a portable electronic apparatus comprising the semiconductor storage device. The present invention can fully cope with scale-down and high-integration by constituting a selectable memory cell substantially of one device.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: January 16, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Iwata, Akihide Shibata
  • Patent number: 7161207
    Abstract: A computer system comprising: (A) a CPU; (B) a memory arrangement comprising: (i) a side-wall memory array including a plurality of side-wall memory transistors; (ii) a charge pump; (iii) a plurality of switching circuits; and (iv) logic circuitry; and (C) a system bus, wherein each of the side-wall memory transistors comprises: a gate electrode formed on a semiconductor layer with a gate insulating film formed on the semiconductor layer; a channel region formed below the gate electrode; a pair of diffusion regions formed on the both sides of the channel region and having a conductive type opposite to that of the channel region; and a pair of memory functional units formed on the both sides of the gate electrode and having a function of retaining charges.
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: January 9, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koji Hamaguchi, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Patent number: 7141849
    Abstract: In a semiconductor storage device, a gate insulating film and a gate electrode are laid on a first conductivity type semiconductor substrate, and charge holding portions are formed on both sides of the gate electrode. Second conductivity type first and second diffusion layer regions are formed in regions of the semiconductor substrate corresponding to the charge holding portions. The charge holding portions are each structured so as to change, in accordance with an electric charge amount held in the charge holding portions, a current amount flowing from one of the second conductivity type diffusion layer regions to the other of the diffusion layer regions through a channel region when voltage is applied to the gate electrode. Part of each charge holding portion is present below an interface of the gate insulating film and the channel region.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: November 28, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Iwata, Akihide Shibata
  • Patent number: 7139202
    Abstract: A semiconductor storage device is provided, which comprises a memory array comprising memory elements, a write state machine for applying a first voltage for performing a write or erase operation, with respect to one of the memory elements, to the memory element via a bit line connected thereto, and thereafter, applying a second voltage for verifying whether or not the write or erase operation has been performed, to the memory element via the bit line, and a reset portion for grounding the bit line connected to the memory element after the write state machine has applied the first voltage and before the write state machine has applied the second voltage. Each memory element comprises a gate electrode, a channel region, diffusion regions, and memory function sections provided on opposite sides of the gate electrode and having a function of retaining charges.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: November 21, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Nobuaki Matsuoka, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20060244070
    Abstract: A semiconductor storage device has memory function bodies (261, 262) having a function to retain electric charges, which are formed on opposite sides of a single gate electrode (217) provided on a semiconductor layer (211) with a gate insulation film (214) disposed therebetween. Each memory function body includes a charge retention film (242) having a charge storage region (250). The charge storage regions (250) exist over part of the channel region (273) and part of diffusion regions (212, 213) on both sides of the channel region. Because the memory function bodies are formed on both sides of the gate electrode, independently of the gate insulation film, 2-bit operations are possible. Because the memory function bodies are separated from each other by the gate electrode, interference during rewrite operation is effectively suppressed. Also, short-channel effect is suppressed through thinning of the gate insulation film. Miniaturization of memory elements is thus facilitated.
    Type: Application
    Filed: December 19, 2003
    Publication date: November 2, 2006
    Inventors: Hiroshi Iwata, Akihide Shibata
  • Publication number: 20060244049
    Abstract: A memory cell array employs a memory element as a memory cell. The memory element is constructed of a gate electrode formed via a gate insulation film on a semiconductor layer, a channel region arranged under the gate electrode, diffusion regions that are arranged on both sides of the channel region and have a conductive type opposite to that of the channel region, and memory function bodies that are arranged on both sides of the gate electrode and have a function to retain electric charges. When first and second power voltages VCC1 and VCC2 supplied from the outside are lower than a prescribed voltage, a rewrite command to a memory circuit 34 that includes the memory cell array is inhibited by a lockout circuit 33a.
    Type: Application
    Filed: October 2, 2003
    Publication date: November 2, 2006
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Kei Tokui, Masaru Nawaki
  • Patent number: 7129539
    Abstract: A semiconductor storage device includes a field effect transistor which has a gate insulator, a gate electrode and a pair of source/drain diffusion regions on a semiconductor substrate. The device also includes a coating film made of a dielectric having a function of storing electric charge and formed on the substrate in such a manner as to cover an upper surface and side surfaces of the gate electrode. The device further includes an interlayer insulator formed on and in contact with the coating film. The device still further includes contact members which extend vertically through the interlayer insulator and the coating film on the source/drain diffusion regions and which are electrically connected to the source/drain diffusion regions, respectively. The coating film and the interlayer insulator are made of materials which are selectively etchable to each other. Thus, the issues of overerase and read failures due to the overerase can be solved, and the device reliability can be enhanced.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: October 31, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroshi Iwata, Takayuki Ogura, Akihide Shibata, Kouichirou Adachi
  • Patent number: 7116579
    Abstract: A semiconductor storage device is provided, which comprises a memory array comprising memory elements, a write state machine for performing a sequence of a program or erase operation with respect to the memory array, a decoder for decoding a signal indicating a current state of the write state machine, which is output from the write state machine, and outputting a status signal indicating a status of the program or erase operation with respect to the memory array, a status register for storing the status signal, and an output circuit for outputting the status signal stored in the status register. Each memory element comprises a gate electrode, a channel region, diffusion regions, and memory function sections provided on opposite sides of the gate electrode and having a function of retaining charges.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: October 3, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinao Morikawa, Masaru Nawaki, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20060208312
    Abstract: A semiconductor storage device includes a field effect transistor which has a gate insulator, a gate electrode and a pair of source/drain diffusion regions on a semiconductor substrate. The device also includes a coating film made of a dielectric having a function of storing electric charge and formed on the substrate in such a manner as to cover an upper surface and side surfaces of the gate electrode. The device further includes an interlayer insulator formed on and in contact with the coating film. The device still further includes contact members which extend vertically through the interlayer insulator and the coating film on the source/drain diffusion regions and which are electrically connected to the source/drain diffusion regions, respectively. The coating film and the interlayer insulator are made of materials which are selectively etchable to each other. Thus, the issues of overerase and read failures due to the overerase can be solved, and the device reliability can be enhanced.
    Type: Application
    Filed: May 1, 2006
    Publication date: September 21, 2006
    Inventors: Hiroshi Iwata, Takayuki Ogura, Akihide Shibata, Kouichirou Adachi
  • Patent number: 7110297
    Abstract: A semiconductor storage device is provided, which comprises a memory array comprising memory elements. Each memory element comprises a gate electrode, a channel region, first and second diffusion regions, and first and second memory function sections provided an opposite aides of the gate electrode and having a function of retaining charges. The device further comprises a row decoder for selecting a word line in accordance with a row address, and a write control circuit for applying a write pulse to a bit line, which is connected to one of the first and second diffusion regions of the memory element connected to the selected word line, in accordance with a column address. The write control circuit controls the application of the write pulse so that a quantity of charges retained in one of the first and second memory function sections corresponds to a value of multibit data.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: September 19, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshinao Morikawa, Masaru Nawaki, Hiroshi Iwata, Akihide Shibata
  • Patent number: 7106630
    Abstract: A semiconductor storage device is provided, which comprises a memory array comprising a plurality of memory elements, a section for performing an erase or program operation with respect to the memory array, a section for receiving a suspend command, and in response to the suspend command, suspending the erase or program operation, and a section for receiving a resume command, and in response to the resume command, resuming the suspended erase or program operation. Each of the plurality of memory elements comprises a gate electrode provided via a gate insulating film on a semiconductor layer, a channel region provided under the gate electrode, diffusion regions provided on opposite sides of the channel region and having a conductivity type opposite to that of the channel region, and memory function sections provided on opposite sides of the gate electrode and having a function of retaining charges.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: September 12, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Koji Hamaguchi, Masaru Nawaki, Yoshinao Morikawa, Hiroshi Iwata, Akihide Shibata
  • Publication number: 20060197142
    Abstract: A semiconductor storage device has a semiconductor layer having a first conductivity type region and two second conductivity type regions separated from each other by the first conductivity type region, a memory function body formed on a surface of the semiconductor layer, and a gate electrode. The memory function body has a charge storage insulator and a charge retention insulator positioned between the charge storage insulator and the semiconductor layer, and doubles as a gate insulating film. The charge retention insulator contains such impurity atoms (phosphorus) as would cause an intrinsic semiconductor to be of the second conductivity type.
    Type: Application
    Filed: March 3, 2006
    Publication date: September 7, 2006
    Inventors: Hiroshi Iwata, Akihide Shibata, Masayuki Nakano
  • Patent number: 7102941
    Abstract: A semiconductor memory device including (A) a global line; (B) a memory array having (i) a local line, (ii) a decoder connected to the global line and the local line, and (iii) a memory block and a redundant block each constructed by a plurality of memory cells each having a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region disposed below the gate electrode, a diffusion region disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and a memory functional unit formed on both sides of the gate electrode and having the function of retaining charges, the memory array having the function that when the decoder is usable, the global line is selectively connected to one of the local lines in accordance with address information and, when a defective block is included in the memory blocks and the decoder is unusable, the local line is separated from the global line and the defective block is replaced with the redundant
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: September 5, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Masaru Nawaki, Yasuaki Iwase, Yoshinao Morikawa
  • Patent number: 7095077
    Abstract: A semiconductor memory includes: a p-type semiconductor (p-type semiconductor film on a substrate, a p-type well region in a semiconductor substrate, or an insulator); a gate insulating film formed on the p-type semiconductor; a gate electrode formed on the gate insulating film; two charge storage sections formed on side walls of the gate electrode; a channel region provided below the gate electrode; and a first n-type diffusion layer region and a second n-type diffusion layer region provided to sides of the channel region, wherein: the charge storage sections are arranged to change an electric current flow between the first n-type diffusion layer region and the second n-type diffusion layer region under application of a voltage to the gate electrode according to the quantity of electric charges stored in the charge storage sections; and the first n-type diffusion layer region is set to a reference voltage, the other n-type diffusion layer region is set to a voltage greater than the reference voltage, and the
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: August 22, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kotaro Kataoka, Hiroshi Iwata, Akihide Shibata
  • Patent number: 7092295
    Abstract: A semiconductor memory device includes a controller programming a nonvolatile memory cell by applying a first pulse so that a charge amount smaller than a target charge amount is accumulated in the nonvolatile memory cell, a second pulse train so that a second charge amount smaller than the target charge amount and larger than the first charge amount is accumulated in the nonvolatile memory cell, and a third pulse train so that a third charge amount falling within an allowable error range of the target charge amount is accumulated. The semiconductor memory cell includes a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region disposed under the gate electrode, diffusion regions disposed on both sides of the channel region and memory functional units formed on both sides of the gate electrode.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: August 15, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuaki Iwase, Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki
  • Patent number: 7088618
    Abstract: A characteristic evaluating method of precisely obtaining a resistance value of an offset region in a semiconductor memory element constructed so that the resistance value of the offset region positioned below a memory function element formed on one side or both sides of a gate electrode changes according to an amount of charges or a polarization state of charges accumulated in said memory function element includes: a step of obtaining each of a resistance value between two diffusion regions inclusive formed on both sides of a channel region disposed just below the gate electrode of the semiconductor memory element via a gate insulating film, a resistance value of the channel region, and a resistance value of the diffusion regions; and a step of calculating the resistance value of the offset region which isolates the channel region and the diffusion region from each other on the basis of a result of subtracting the resistance value of the channel region and the resistance value of the diffusion regions from t
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: August 8, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kozo Hoshino, Hiroshi Iwata, Akihide Shibata
  • Patent number: 7085166
    Abstract: A semiconductor memory device includes: a plurality of nonvolatile memory cells; a first load cell for generating a read voltage relative to a read current during reading from a selected nonvolatile memory cell; a reference cell for storing a reference state corresponding to a reference current of the selected nonvolatile memory cell; a second load cell for generating a voltage based on the reference current through the reference cell; and a programming circuit for generating a reference voltage equal to a voltage obtained from a specific current-voltage characteristic of the first load cell with respect to the reference current and programming the reference cell so as to equalize the voltage of the second load cell with the reference voltage, thereby to compensate for variations in the first load cell.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: August 1, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuaki Iwase, Yoshifumi Yaoi, Hiroshi Iwata, Akihide Shibata, Yoshinao Morikawa, Masaru Nawaki