Patents by Inventor Koichiro Ishibashi

Koichiro Ishibashi 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: 7569881
    Abstract: The gate tunnel leakage current is increased in the up-to-date process, so that it is necessary to reduce the gate tunnel leakage current in the LSI which is driven by a battery for use in a cellular phone and which needs to be in a standby mode at a low leakage current. In a semiconductor integrated circuit device, the ground source electrode lines of logic and memory circuits are kept at a ground potential in an active mode, and are kept at a voltage higher than the ground potential in an unselected standby mode. The gate tunnel leakage current can be reduced without destroying data.
    Type: Grant
    Filed: April 9, 2008
    Date of Patent: August 4, 2009
    Assignees: Renesas Technology Corporation, Hitachi ULSI Systems Co., Ltd.
    Inventors: Kenichi Osada, Koichiro Ishibashi, Yoshikazu Saitoh, Akio Nishida, Masaru Nakamichi, Naoki Kitai
  • Publication number: 20090141569
    Abstract: Cell power supply lines are arranged for memory cell columns, and adjust impedances or voltage levels of the cell power supply lines according to the voltage levels of bit lines in the corresponding columns, respectively. In the data write operation, the cell power supply line is forced into a floating state according to the bit line potential on a selected column and has the voltage level changed, and a latching capability of a selected memory cell is reduced to write data fast. Even with a low power supply voltage, a static semiconductor memory device that can stably perform write and read of data is implemented.
    Type: Application
    Filed: February 9, 2009
    Publication date: June 4, 2009
    Applicant: RENESAS TECHNOLOGY CORP
    Inventors: Koji NII, Shigeki Obayashi, Hiroshi Makino, Koichiro Ishibashi, Hirofumi Shinohara
  • Publication number: 20090116282
    Abstract: Prior known static random access memory (SRAM) cells are required that a diffusion layer be bent into a key-like shape in order to make electrical contact with a substrate with a P-type well region formed therein, which would result in a decrease in asymmetry leading to occurrence of a problem as to the difficulty in micro-patterning. To avoid this problem, the P-type well region in which an inverter making up an SRAM cell is formed is subdivided into two portions, which are disposed on the opposite sides of an N-type well region NW1 and are formed so that a diffusion layer forming a transistor has no curvature while causing the layout direction to run in a direction parallel to well boundary lines and bit lines. At intermediate locations of an array, regions for use in supplying power to the substrate are formed in parallel to word lines in such a manner that one regions is provided per group of thirty two memory cell rows or sixty four cell rows.
    Type: Application
    Filed: January 5, 2009
    Publication date: May 7, 2009
    Inventors: Kenichi OSADA, Masataka Minami, Shuji Ikeda, Koichiro Ishibashi
  • Publication number: 20090097302
    Abstract: A logic circuit in a system LSI is provided with a power switch so as to cut off the switch at the time of standby, reducing leakage current. At the same time, an SRAM circuit of the system LSI controls a substrate bias to reduce leakage current.
    Type: Application
    Filed: December 1, 2008
    Publication date: April 16, 2009
    Inventors: Masanao Yamaoka, Koichiro Ishibashi, Shigezumi Matsui, Kenichi Osada
  • Patent number: 7518404
    Abstract: A semiconductor device which includes a frequency-variable oscillation circuit including plural inverters, each of which features a PMOS transistor and a NMOS transistor, a first substrate bias generator including a first phase/frequency compare circuit that compares an output signal from the frequency-variable oscillation circuit with a reference clock signal and generating a first substrate bias voltage in response thereto, the first substrate bias voltage being supplied to substrates of the PMOS transistors in the oscillation circuit, and a second substrate bias generator including a second phase/frequency compare circuit that compares the output signal from the frequency-variable oscillation circuit with the reference clock and generating a second substrate bias voltage in response thereto, the second substrate bias voltage being supplied to substrates of the NMOS transistors in the oscillation circuit.
    Type: Grant
    Filed: January 7, 2008
    Date of Patent: April 14, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Hiroyuki Mizuno, Koichiro Ishibashi, Masayuki Miyazaki
  • Publication number: 20090079465
    Abstract: The present invention aims to make each power shutdown area appropriate. Cell areas each comprising a plurality of core cells arranged therein, and power switches disposed corresponding to the respective cell areas are provided. A plurality of power shutdown areas are respectively formed in units of the core cells. In each power shutdown area, power shutdown is enabled by the power switches corresponding to the power shutdown areas. Thus, the power shutdown areas can be set finely in the core cell units, and the appropriateness of each power shutdown area is achieved. With its appropriateness, a reduction in current consumption at standby is achieved.
    Type: Application
    Filed: April 21, 2005
    Publication date: March 26, 2009
    Inventors: Toshio Sasaki, Yoshihiko Yasu, Ryo Mori, Koichiro Ishibashi, Yusuke Kanno
  • Patent number: 7502275
    Abstract: Cell power supply lines are arranged for memory cell columns, and adjust impedances or voltage levels of the cell power supply lines according to the voltage levels of bit lines in the corresponding columns, respectively. In the data write operation, the cell power supply line is forced into a floating state according to the bit line potential on a selected column and has the voltage level changed, and a latching capability of a selected memory cell is reduced to write data fast. Even with a low power supply voltage, a static semiconductor memory device that can stably perform write and read of data is implemented.
    Type: Grant
    Filed: May 23, 2006
    Date of Patent: March 10, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Koji Nii, Shigeki Obayashi, Hiroshi Makino, Koichiro Ishibashi, Hirofumi Shinohara
  • Publication number: 20090010042
    Abstract: In an integrated circuit device, there are various optimum gate lengths, thickness of gate oxide films, and threshold voltages according to the characteristics of circuits. In a semiconductor integrated circuit device in which the circuits are integrated on the same substrate, the manufacturing process is complicated in order to set the circuits to the optimum values. As a result, in association with deterioration in the yield and increase in the number of manufacturing days, the manufacturing cost increases. In order to solve the problems, according to the invention, transistors of high and low thresholds are used in a logic circuit, a memory cell uses a transistor of the same high threshold voltage and a low threshold voltage transistor, and an input/output circuit uses a transistor having the same high threshold voltage and the same concentration in a channel, and a thicker gate oxide film.
    Type: Application
    Filed: July 10, 2008
    Publication date: January 8, 2009
    Inventors: Koichiro Ishibashi, Kenichi Osada
  • Patent number: 7475261
    Abstract: The feature of the present invention consists in: a processor main circuit for executing program instruction strings on a processor chip; a substrate bias switching unit for switching voltages of substrate biases applied to a substrate of the processor main circuit; and an operation mode control unit for controlling, in response to the execution of an instruction to proceed to a stand-by mode in the processor main circuit, the substrate bias switching unit in such a way that the biases are switched over to voltages for the stand-by mode, and for controlling, in response to an interruption of the stand-by release from the outside, the substrate bias switching unit in such a way that the biases are switched over to voltages for a normal mode, and also for releasing, after the bias voltages switched thereto have been stabilized, the stand-by of the processor main circuit to restart the operation.
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: January 6, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Yonetaro Totsuka, Koichiro Ishibashi, Hiroyuki Mizuno, Osamu Nishii, Kunio Uchiyama, Takanori Shimura, Asako Sekine, Yoichi Katsuki, Susumu Narita
  • Patent number: 7474584
    Abstract: A logic circuit in a system LSI is provided with a power switch so as to cut off the switch at the time of standby, reducing leakage current. At the same time, an SRAM circuit of the system LSI controls a substrate bias to reduce leakage current.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: January 6, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Masanao Yamaoka, Koichiro Ishibashi, Shigezumi Matsui, Kenichi Osada
  • Publication number: 20080247220
    Abstract: A memory using an SRAM memory cell intended for low-voltage operation is designed to decrease the threshold value of MOS transistors constituting the memory cell without substantial decrease in the static noise margin, which is the operational margin of the memory cell. To this end, a voltage Vdd? higher than a power supply voltage Vdd of a power supply line for peripheral circuits is supplied from a power supply line for memory cells as a power supply voltage for memory cells. Since the conductance of driver MOS transistors is in-creased, the threshold voltage of the MOS transistors within the memory cells can be reduced without reducing the static noise margin. Further the ratio of width between the driver MOS transistor and a transfer MOS transistor can be set to 1, thereby allowing a reduction in the memory cell area.
    Type: Application
    Filed: June 4, 2008
    Publication date: October 9, 2008
    Inventors: Masanao Yamaoka, Kenichi Osada, Koichiro Ishibashi
  • Publication number: 20080203437
    Abstract: The gate tunnel leakage current is increased in the up-to-date process, so that it is necessary to reduce the gate tunnel leakage current in the LSI which is driven by a battery for use in a cellular phone and which needs to be in a standby mode at a low leakage current. In a semiconductor integrated circuit device, the ground source electrode lines of logic and memory circuits are kept at a ground potential in an active mode, and are kept at a voltage higher than the ground potential in an unselected standby mode. The gate tunnel leakage current can be reduced without destroying data.
    Type: Application
    Filed: April 9, 2008
    Publication date: August 28, 2008
    Inventors: Kenichi Osada, Koichiro Ishibashi, Yoshikazu Saitoh, Akio Nishida, Masaru Nakamichi, Naoki Kitai
  • Patent number: 7408231
    Abstract: In an integrated circuit device, there are various optimum gate lengths, thickness of gate oxide films, and threshold voltages according to the characteristics of circuits. In a semiconductor integrated circuit device in which the circuits are integrated on the same substrate, the manufacturing process is complicated in order to set the circuits to the optimum values. As a result, in association with deterioration in the yield and increase in the number of manufacturing days, the manufacturing cost increases. In order to solve the problems, according to the invention, transistors of high and low thresholds are used in a logic circuit, a memory cell uses a transistor of the same high threshold voltage and a low threshold voltage transistor, and an input/output circuit uses a transistor having the same high threshold voltage and the same concentration in a channel, and a thicker gate oxide film.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: August 5, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Koichiro Ishibashi, Kenichi Osada
  • Patent number: 7406643
    Abstract: A semiconductor integrated circuit device which guarantees the characteristics of writing to and reading from the built-in memory even when the manufacturing process conditions are varied, a method of manufacturing the device, and a medium for storing a processing procedure for deciding the number of delay circuits built in the device used for designing. The semiconductor integrated circuit device is provided with a cache memory which includes a BIST circuit composed of a pattern generator, a pattern comparator, an output register, a register controlled by a register control a register write signal; a variable delay circuit controlled by the register; word lines, and a sense amplifier enable signal line. The timing for enabling the sense amplifier is changed and the memory is measured by a BIST circuit at the timing, thereby deciding the optimal timing.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: July 29, 2008
    Assignee: Renesas Technology Corporation
    Inventors: Kenichi Osada, Koichiro Ishibashi, Kazuo Yano, Tetsuro Honmura
  • Patent number: 7397282
    Abstract: A semiconductor integrated circuit device which includes a logical circuit containing a MIS transistor on a semiconductor substrate, a control circuit for controlling a threshold voltage of the MIS transistor in the logical circuit, an oscillation circuit containing a MIS transistor on the semiconductor substrate, and a buffer circuit, the control circuit compares the frequency of the oscillation output and frequency of a clock signal to output a first control signal, the first control signal controls a threshold voltage of the MIS transistor of the oscillation circuit, and the buffer circuit is inputted with the first control signal to output a second control signal corresponding to the first control signal, the second control signal controlling the threshold voltage of the MIS transistor of the logical circuit.
    Type: Grant
    Filed: September 26, 2006
    Date of Patent: July 8, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Hiroyuki Mizuno, Koichiro Ishibashi, Masayuki Miyazaki
  • Patent number: 7397693
    Abstract: A memory using an SRAM memory cell intended for low-voltage operation is designed to decrease the threshold value of MOS transistors constituting the memory cell without substantial decrease in the static noise margin, which is the operational margin of the memory cell. To this end, a voltage Vdd? higher than a power supply voltage Vdd of a power supply line for peripheral circuits is supplied from a power supply line for memory cells as a power supply voltage for memory cells. Since the conductance of driver MOS transistors is in-creased, the threshold voltage of the MOS transistors within the memory cells can be reduced without reducing the static noise margin. Further the ratio of width between the driver MOS transistor and a transfer MOS transistor can be set to 1, thereby allowing a reduction in the memory cell area.
    Type: Grant
    Filed: January 24, 2007
    Date of Patent: July 8, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Masanao Yamaoka, Kenichi Osada, Koichiro Ishibashi
  • Publication number: 20080143423
    Abstract: The present invention is directed to realize high manufacture yield and compensate variations in threshold voltage of a MOS transistor with small overhead. A semiconductor integrated circuit includes a CMOS circuit for processing an input signal in an active mode, a control switch, and a control memory. The control switch supplies a pMOS body bias voltage and an nMOS body bias voltage to an N well in a pMOS transistor and a P well in an nMOS transistor, respectively, in the CMOS circuit. The control memory stores control information indicating whether or not the pMOS body bias voltage and the nMOS body bias voltage are supplied from the control switch to the N well in the pMOS transistor and the P well in the nMOS transistor, respectively, in the CMOS circuit in the active mode.
    Type: Application
    Filed: November 20, 2007
    Publication date: June 19, 2008
    Inventors: Shigenobu Komatsu, Kenichi Osada, Masanao Yamaoka, Koichiro Ishibashi
  • Patent number: 7388238
    Abstract: The gate tunnel leakage current is increased in the up-to-date process, so that it is necessary to reduce the gate tunnel leakage current in the LSI which is driven by a battery for use in a cellular phone and which needs to be in a standby mode at a low leakage current. In a semiconductor integrated circuit device, the ground source electrode lines of logic and memory circuits are kept at a ground potential in an active mode, and are kept at a voltage higher than the ground potential in an unselected standby mode. The gate tunnel leakage current can be reduced without destroying data.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: June 17, 2008
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Kenichi Osada, Koichiro Ishibashi, Yoshikazu Saitoh, Akio Nishida, Masaru Nakamichi, Naoki Kitai
  • Publication number: 20080136502
    Abstract: In order to provide a semiconductor IC unit such as a microprocessor, etc., which satisfies both fast operation and lower power consumption properties with its high quality kept, the semiconductor IC unit of the present invention is composed so as to include a main circuit (LOG) provided with transistors, which is formed on a semiconductor substrate, and a substrate bias controlling circuit (VBC) used for controlling a voltage to be applied to the substrate, and the main circuit includes switching transistors (MN1 and MP1) used for controlling a voltage to be applied to the substrate and control signals output from the substrate bias controlling circuit is entered to the gate of each of the switching transistors and the control signal is returned to the substrate bias controlling circuit.
    Type: Application
    Filed: November 27, 2007
    Publication date: June 12, 2008
    Inventors: Hiroyuki Mizuno, Koichiro Ishibashi, Takanori Shimura, Toshihiro Hattori
  • Publication number: 20080116934
    Abstract: A semiconductor device which includes a frequency-variable oscillation circuit including plural inverters, each of which features a PMOS transistor and a NMOS transistor, a first substrate bias generator including a first phase/frequency compare circuit that compares an output signal from the frequency-variable oscillation circuit with a reference clock signal and generating a first substrate bias voltage in response thereto, the first substrate bias voltage being supplied to substrates of the PMOS transistors in the oscillation circuit, and a second substrate bias generator including a second phase/frequency compare circuit that compares the output signal from the frequency-variable oscillation circuit with the reference clock and generating a second substrate bias voltage in response thereto, the second substrate bias voltage being supplied to substrates of the NMOS transistors in the oscillation circuit.
    Type: Application
    Filed: January 7, 2008
    Publication date: May 22, 2008
    Inventors: Hiroyuki Mizuno, Koichiro Ishibashi, Masayuki Miyazaki