Patents by Inventor Katsutaka Kimura

Katsutaka Kimura 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: 6687156
    Abstract: In a semiconductor integrated circuit device including a third gate, the present invention improves miniaturization and operation speed and reduces a defect density of an insulator film. In a semiconductor integrated circuit device including a well of a first conductivity type formed in a semiconductor substrate, a source/drain diffusion layer of a second conductivity type inside the well, a floating gate formed over the semiconductor substrate through an insulator film, a control gate formed and isolated from the floating gate through an insulator film, word lines formed by connecting the control gates and a third gate formed and isolated from the semiconductor substrate, the floating gate and the control gate through an insulator film and different from the floating gate and the control gate, the third gate is buried into a space of the floating gates existing in a direction vertical to the word line and a channel.
    Type: Grant
    Filed: July 30, 2002
    Date of Patent: February 3, 2004
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Takashi Kobayashi, Hideaki Kurata, Naoki Kobayashi, Hitoshi Kume, Katsutaka Kimura, Shunichi Saeki
  • Patent number: 6671198
    Abstract: When a phase shift method is used as lithography where sense amplifiers are alternately placed in a one intersecting-point memory capable of implementing a reduction in the area of a DRAM, it was difficult to layout data lines in a boundary region between sense amplifiers and each memory array. Therefore, there is provided a semiconductor device according to the present invention. In the semiconductor device, two data lines continuous within the sub memory arrays or interposed therebetween are connected to the adjacent sense amplifiers as a system for drawing data lines from sub memory arrays (SMA) to sense amplifiers (SA) when the sense amplifiers are alternately placed. Namely, the number of data lines interposed between data lines respectively connected to two adjacent sense amplifiers is set to even numbers (0, 2, 4, . . . ).
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: December 30, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Tomonori Sekiguchi, Katsutaka Kimura, Kazuhiko Kajigaya, Tsugio Takahashi
  • Patent number: 6668344
    Abstract: A semiconductor memory device comprising a redundancy circuit having a small area and high repair efficiency in which time required to store the address of a defect is short and which can reduce the manufacturing cost of the device is disclosed. Repairing addresses are sorted and stored in accordance with a specific order. In case of storing four addresses for eight addresses, a set SFG of fuses corresponding to eight decoded addresses DA0 to DA7 is provided and information indicative of the ordinal position of the fuse in the corresponding fuse-decision results which are logic 1 is used to associate the address with the repair-decision result.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: December 23, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Sakata, Tsugio Takahashi, Katsutaka Kimura, Tomonori Sekiguchi
  • Patent number: 6636437
    Abstract: In a nonvolatile semiconductor memory device capable of the storage of multivalued data, fast writing can be realized with high reliability. In such a nonvolatile semiconductor memory device for storing multivalued information in one memory cell by setting a plurality of threshold voltages of data, writing of data having one threshold voltage that is the remotest to an erased state is performed prior to writing of the data having the other threshold voltages (write #1). Writing of the data having the other threshold voltages is then sequentially performed within groups of threshold voltages, starting from the nearer threshold voltage to the erased state within each group. When writing each of the data having the other threshold voltages, writing of the data is performed to a memory cell beginning with those groups having the remoter threshold voltages from the erased state.
    Type: Grant
    Filed: October 1, 2002
    Date of Patent: October 21, 2003
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Naoki Kobayashi, Hideaki Kurata, Katsutaka Kimura, Takashi Kobayashi, Shunichi Saeki
  • Patent number: 6625051
    Abstract: In a large scale integrated DRAM in pursuit of micro fabrication, data line-word line coupling capacitances are unbalanced between paired data lines. A data line-word line imbalance generates large noise when the data lines are subjected to amplification, which is highly likely to invite deterioration of very small signals on the data lines and erroneous amplification of data. One or a few of a plurality of word lines connected to a plurality of memory cells connected to one data line are alternately connected to subword driver arrays arranged on the opposing sides of a memory array. Positive and negative word line noise components cancel each other in the subword drivers when the data lines are subjected to amplification, so that the word line noise can be reduced. Therefore, signals read out by sense amplifiers can be prevented from deterioration thereby to increase the reliability of memory operation.
    Type: Grant
    Filed: May 28, 2002
    Date of Patent: September 23, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Sekiguchi, Riichiro Takemura, Kazuhiko Kajigaya, Katsutaka Kimura, Tsugio Takahashi
  • Publication number: 20030142528
    Abstract: When a phase shift method is used as lithography where sense amplifiers are alternately placed in a one intersecting-point memory capable of implementing a reduction in the area of a DRAM, it was difficult to layout data lines in a boundary region between sense amplifiers and each memory array. Therefore, there is provided a semiconductor device according to the present invention. In the semiconductor device, two data lines continuous within the sub memory arrays or interposed therebetween are connected to the adjacent sense amplifiers as a system for drawing data lines from sub memory arrays (SMA) to sense amplifiers (SA) when the sense amplifiers are alternately placed. Namely, the number of data lines interposed between data lines respectively connected to two adjacent sense amplifiers is set to even numbers (0, 2, 4, . . . ).
    Type: Application
    Filed: January 30, 2003
    Publication date: July 31, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Tomonori Sekiguchi, Katsutaka Kimura, Kazuhiko Kajigaya, Tsugio Takahashi
  • Publication number: 20030137863
    Abstract: A sense amplifier capable of performing high-speed data sense operation with lower power consumption using a minuscule signal from a memory cell even in a case where a memory array voltage is reduced. A plurality of drive switches for over-driving are distributively arranged in a sense amplifier area, and a plurality of drive switches for restore operation are concentratively disposed at one end of a row of the sense amplifiers. A potential for over-driving is supplied using a meshed power line circuit. Through the use of the drive switches for over-driving, initial sense operation can be performed on data line pairs with a voltage having an amplitude larger than a data-line amplitude, allowing implementation of high-speed sense operation. The distributed arrangement of the drive switched for over-driving makes it possible to dispersively supply current in sense operation, thereby reducing a difference in sense voltage with respect to far and near positions of the sense amplifiers.
    Type: Application
    Filed: January 22, 2003
    Publication date: July 24, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Kiyoo Itoh, Tomonori Sekiguchi, Takeshi Sakata, Katsutaka Kimura
  • Publication number: 20030133353
    Abstract: Disclosed is a nonvolatile memory system including at least one nonvolatile memory each having a plurality of nonvolatile memory cells and a buffer memory; and a control device coupled to the nonvolatile memory. The control device is enabled to receive external data and to apply the data to the nonvolatile memory, and the nonvolatile memory is enabled to operate a program operation including storing the received data to the buffer memory and storing the data held in the buffer memory to ones of nonvolatile memory cells. Moreover, the control device is enabled to receive external data while the nonvolatile memory is operating in the program operation. Also, the buffer memory is capable of receiving a unit of data, equal to the data length of data to be stored at one time of the program operation, the data length being more than 1 byte.
    Type: Application
    Filed: January 27, 2003
    Publication date: July 17, 2003
    Inventors: Masataka Kato, Tetsuo Adachi, Toshihiro Tanaka, Toshio Sasaki, Hitoshi Kume, Katsutaka Kimura
  • Publication number: 20030112682
    Abstract: Disclosed herein is a dynamic RAM comprising a plurality of word lines respectively connected to address select terminals of a plurality of dynamic memory cells, a plurality of complementary bit line pairs respectively connected to input/output terminals of the plurality of dynamic memory cells and placed in directions opposite to one another, and a sense amplifier array which is supplied with an operating voltage according to an operation timing signal and comprises a plurality of latch circuits for respectively amplifying the differences in voltage between the complementary bit line pairs.
    Type: Application
    Filed: December 4, 2002
    Publication date: June 19, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Tomonori Sekiguchi, Kazuhiko Kajigaya, Katsutaka Kimura, Riichiro Takemura, Tsugio Takahashi, Yoshitaka Nakamura
  • Patent number: 6570419
    Abstract: A clock recovery circuit is provided for use in a memory with a clock synchronized interface, wherein an external clock is temporarily intercepted to shorten lock-in time when an internal clock is to be generated from the external clock. The clock recovery circuit includes a delay circuit array, receiving the external clock, for generating reference clocks, a control circuit comparing phases of the external clock and of the reference clocks and detecting the number of delay stages required for locking in, and a latching circuit for holding the number of delay stages required for locking in. Once synchronism is detected, the generation of internal clock can be resumed in a short period of time even if the supply of the external clock is temporarily suspended.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: May 27, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Hanzawa, Takeshi Sakata, Katsutaka Kimura
  • Patent number: 6556474
    Abstract: In a nonvolatile semiconductor memory device capable of the storage of multivalued data, fast writing can be realized with high reliability. In such a nonvolatile semiconductor memory device for storing multivalued information in one memory cell by setting a plurality of threshold voltages of data, writing of data having one threshold voltage that is the remotest to an erased state is performed prior to writing of the data having the other threshold voltages (write #1). Writing of the data having the other threshold voltages is then sequentially performed within groups of threshold voltages, starting from the nearer threshold voltage to the erased state within each group. When writing each of the data having the other threshold voltages, writing of the data is performed to a memory cell beginning with those groups having the remoter threshold voltages from the erased state.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: April 29, 2003
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Naoki Kobayashi, Hideaki Kurata, Katsutaka Kimura, Takashi Kobayashi, Shunichi Saeki
  • Patent number: 6545902
    Abstract: Since a ferroelectric memory device cannot employ a VCC/2 precharge scheme widely used in DRAM, its array noise and power consumption are large. Further, a ferroelectric capacitor is deteriorated in its characteristics due to its fatigue and imprint. To avoid this, data line pairs are precharged to two voltages VCC and VSS. As a result, a voltage on a data line in a memory cell array MCA varies symmetrically with respect to VCC/2 as its center to thereby reduce the array noise. Further, when early sense and early precharge operations are carried out based on charge sharing between data lines of different precharge voltages, the power consumption can be reduced. Furthermore, when the precharge voltages are switched for respective data lines, reverse and non-reverse polarization are alternately carried out in the ferroelectric capacitor in the memory cell to suppress its fatigue and imprint.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: April 8, 2003
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Takeshi Sakata, Tomonori Sekiguchi, Hiroki Fujisawa, Katsutaka Kimura, Masanori Isoda, Kazuhiko Kajigaya
  • Publication number: 20030062550
    Abstract: In a masking pattern (a) for patterning word and data lines, length is changed between adjacent word lines so as to be shifted from each other at their tips, and furthermore, the tip of each word line is cut obliquely.
    Type: Application
    Filed: October 29, 2002
    Publication date: April 3, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Tomonori Sekiguchi, Toshihiko Tanaka, Toshiaki Yamanaka, Takeshi Sakata, Katsutaka Kimura
  • Patent number: 6538926
    Abstract: Disclosed is a nonvolatile memory system including at least one nonvolatile memory each having a plurality of nonvolatile memory cells and a buffer memory; and a control device coupled to the nonvolatile memory. The control device is enabled to receive external data and to apply the data to the nonvolatile memory, and the nonvolatile memory is enabled to operate a program operation including storing the received data to the buffer memory and storing the data held in the buffer memory to ones of nonvolatile memory cells. Moreover, the control device is enabled to receive external data while the nonvolatile memory is operating in the program operation. Also, the buffer memory is capable of receiving a unit of data, equal to the data length of data to be stored at one time of the program operation, the data length being more than 1 byte.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: March 25, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masataka Kato, Tetsuo Adachi, Toshihiro Tanaka, Toshio Sasaki, Hitoshi Kume, Katsutaka Kimura
  • Patent number: 6538912
    Abstract: When a phase shift method is used as lithography where sense amplifiers are alternately placed in a one intersecting-point memory capable of implementing a reduction in the area of a DRAM, it was difficult to layout data lines in a boundary region between sense amplifiers and each memory array. Therefore, there is provided a semiconductor device according to the present invention. In the semiconductor device, two data lines continuous within the sub memory arrays or interposed therebetween are connected to the adjacent sense amplifiers as a system for drawing data lines from sub memory arrays (SMA) to sense amplifiers (SA) when the sense amplifiers are alternately placed. Namely, the number of data lines interposed between data lines respectively connected to two adjacent sense amplifiers is set to even numbers (0, 2, 4, . . . ).
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: March 25, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Tomonori Sekiguchi, Katsutaka Kimura, Kazuhiko Kajigaya, Tsugio Takahashi
  • Patent number: 6535415
    Abstract: A sense amplifier capable of performing high-speed data sense operation with lower power consumption using a minuscule signal from a memory cell even in a case where a memory array voltage is reduced. A plurality of drive switches for over-driving are distributively arranged in a sense amplifier area, and a plurality of drive switches for restore operation are concentratively disposed at one end of a row of the sense amplifiers. A potential for over-driving is supplied using a meshed power line circuit. Through the use of the drive switches for over-driving, initial sense operation can be performed on data line pairs with a voltage having an amplitude larger than a data-line amplitude, allowing implementation of high-speed sense operation. The distributed arrangement of the drive switched for over-driving makes it possible to dispersively supply current in sense operation, thereby reducing a difference in sense voltage with respect to far and near positions of the sense amplifiers.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: March 18, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Kiyoo Itoh, Tomonori Sekiguchi, Takeshi Sakata, Katsutaka Kimura
  • Publication number: 20030026146
    Abstract: In a nonvolatile semiconductor memory device capable of the storage of multivalued data, fast writing can be realized with high reliability. In such a nonvolatile semiconductor memory device for storing multivalued information in one memory cell by setting a plurality of threshold voltages of data, writing of data having one threshold voltage that is the remotest to an erased state is performed prior to writing of the data having the other threshold voltages (write #1). Writing of the data having the other threshold voltages is then sequentially performed within groups of threshold voltages, starting from the nearer threshold voltage to the erased state within each group. When writing each of the data having the other threshold voltages, writing of the data is performed to a memory cell beginning with those groups having the remoter threshold voltages from the erased state.
    Type: Application
    Filed: October 1, 2002
    Publication date: February 6, 2003
    Inventors: Naoki Kobayashi, Hideaki Kurata, Katsutaka Kimura, Takashi Kobayashi, Shunichi Saeki
  • Publication number: 20030016551
    Abstract: A sense amplifier capable of performing high-speed data sense operation with lower power consumption using a minuscule signal from a memory cell even in a case where a memory array voltage is reduced. A plurality of drive switches for over-driving are distributively arranged in a sense amplifier area, and a plurality of drive switches for restore operation are concentratively disposed at one end of a row of the sense amplifiers. A potential for over-driving is supplied using a meshed power line circuit. Through the use of the drive switches for over-driving, initial sense operation can be performed on data line pairs with a voltage having an amplitude larger than a data-line amplitude, allowing implementation of high-speed sense operation. The distributed arrangement of the drive switched for over-driving makes it possible to dispersively supply current in sense operation, thereby reducing a difference in sense voltage with respect to far and near positions of the sense amplifiers.
    Type: Application
    Filed: September 23, 2002
    Publication date: January 23, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Kiyoo Itoh, Tomonori Sekiguchi, Takeshi Sakata, Katsutaka Kimura
  • Patent number: 6510086
    Abstract: Disclosed is a nonvolatile memory system including at least one nonvolatile memory each having a plurality of nonvolatile memory cells and a buffer memory; and a control device coupled to the nonvolatile memory. The control device is enabled to receive external data and to store the data in the nonvolatile memory, and the nonvolatile memory is capable of performing at least a program operation and an erase operation. Moreover, the control device is enabled to receive external data while the nonvolatile memory is operating in the erase operation. Also, the buffer memory is capable of receiving a unit of data, in the program operation, equal to the data length of data to be stored at one time of the program operation, the data length being more than 1 byte.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: January 21, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masataka Kato, Tetsuo Adachi, Toshihiro Tanaka, Toshio Sasaki, Hitoshi Kume, Katsutaka Kimura
  • Patent number: 6501672
    Abstract: A dynamic RAM comprising a plurality of word lines respectively connected to address select terminals of a plurality of dynamic memory cells, a plurality of complementary bit line pairs respectively connected to input/output terminals of the plurality of dynamic memory cells and placed in directions opposite to one another, and a sense amplifier array which is supplied with an operating voltage according to an operation timing signal and comprises a plurality of latch circuits for respectively amplifying the differences in voltage between the complementary bit line pairs. In the dynamic RAM, common electrodes provided, in opposing relationship to storage nodes corresponding to connecting points between address select MOSFETs and information storage capacitors of the plurality of dynamic memory cells, on both sides of the sense amplifier array are connected to one another by wiring using the common electrodes.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: December 31, 2002
    Assignee: Hitachi, LTD
    Inventors: Tomonori Sekiguchi, Kazuhiko Kajigaya, Katsutaka Kimura, Riichiro Takemura, Tsugio Takahashi, Yoshitaka Nakamura