Patents by Inventor Taro Osabe

Taro Osabe 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).

  • Publication number: 20070257306
    Abstract: Disclosed is a non-volatile semiconductor memory device that uses a inversion layer provided on a semiconductor substrate as a data line. The memory device can reduce variation of characteristics among memory cells and can reduce bit cost. A plurality of assist gates are formed in the upper part of a p-type well through a gate oxide film. In the upper part of an interlayer insulator that covers those assist gates are formed word lines that are used as control electrodes. The width of those word lines is, for example, 0.1 ?m, and each word line is separated from its adjacent word lines by a side wall spacer that is a silicon oxide film having a thickness of about 20 nm.
    Type: Application
    Filed: June 7, 2007
    Publication date: November 8, 2007
    Inventors: Tomoyuki Ishii, Taro Osabe, Hideaki Kurata, Takeshi Sakata
  • Publication number: 20070205440
    Abstract: A semiconductor device comprises a floating gate which is formed on a semiconductor substrate of a first conductive type interposing a first gate insulation layer therebetween, a second charge retaining area which is formed on the semiconductor substrate interposing a second insulation layer, a control gate which is formed on the floating gate interposing a second gate insulation layer therebetween, a second gate electrode which extends in the first direction and which is formed on the second charge retaining region interposing the second gate insulation layer therebetween, and a semiconductor layer which extends in a second direction and which is formed on the semiconductor substrate so as to intersect the first and the second gate electrode are provided; wherein an n-type conductive region of a second conductive type is formed on the semiconductor layer. Consequently, it achieves high-integration of a semiconductor device.
    Type: Application
    Filed: December 19, 2006
    Publication date: September 6, 2007
    Inventors: Takashi Ishigaki, Taro Osabe, Takashi Kobayashi, Yutaka Imai, Masahiro Shimizu
  • Publication number: 20070176219
    Abstract: A plurality of floating gates are formed on a principal surface of a semiconductor substrate that constitutes a nonvolatile semiconductor memory device through a first gate dielectric film. An auxiliary gate formed on the principal surface of the semiconductor substrate through a third gate dielectric film is formed on one adjacent side of the floating gates. A groove is formed on the other adjacent side of the floating gate, and an n-type diffusion layer is formed on a bottom side of the groove. A data line of the nonvolatile semiconductor memory device is constituted by an inversion layer formed on the principal surface of the semiconductor substrate to be opposed to an auxiliary gate by applying desired voltage to the auxiliary gate, and the n-type diffusion layer.
    Type: Application
    Filed: December 19, 2006
    Publication date: August 2, 2007
    Inventors: Taro OSABE, Takashi Ishigaki, Yoshitaka Sasago
  • Patent number: 7238570
    Abstract: Disclosed is a non-volatile semiconductor memory device that uses a inversion layer provided on a semiconductor substrate as a data line. The memory device can reduce variation of characteristics among memory cells and can reduce bit cost. A plurality of assist gates are formed in the upper part of a p-type well through a gate oxide film. In the upper part of an interlayer insulator that covers those assist gates are formed word lines that are used as control electrodes. The width of those word lines is, for example, 0.1 ?m, and each word line is separated from its adjacent word lines by a side wall spacer that is a silicon oxide film having a thickness of about 20 nm.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: July 3, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Tomoyuki Ishii, Taro Osabe, Hideaki Kurata, Takeshi Sakata
  • Patent number: 7078762
    Abstract: Disclosed is a non-volatile semiconductor memory device that uses a inversion layer provided on a semiconductor substrate as a data line. The memory device can reduce variation of characteristics among memory cells and can reduce bit cost. A plurality of assist gates are formed in the upper part of a p-type well through a gate oxide film. In the upper part of an interlayer insulator that covers those assist gates are formed word lines that are used as control electrodes. The width of those word lines is, for example, 0.1 ?m, and each word line is separated from its adjacent word lines by a side wall spacer that is a silicon oxide film having a thickness of about 20 nm.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: July 18, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Tomoyuki Ishii, Taro Osabe, Hideaki Kurata, Takeshi Sakata
  • Patent number: 7045854
    Abstract: An object of the present invention is to provide a semiconductor memory device suitable for larger-capacity storage because of its ability to store 3 or more bits in one element and capable of a high-speed and high-efficiency write operation due to a reduced leakage current during the write operation and provide a fabrication method therefor. According to the present invention, each of elements has a source region, a drain region, a control gate, two charge storage regions, and one or more assist gates. During a write operation, source side injection writing is performed with respect to a write target element by using the assist gates, while adjacent elements are isolated by field isolation using the assist gates.
    Type: Grant
    Filed: October 21, 2003
    Date of Patent: May 16, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Taro Osabe, Tomoyuki Ishii, Takashi Kobayashi
  • Patent number: 7045853
    Abstract: In a semiconductor flash memory required to have high reliability, injection and extraction of electrons must be performed through an oxide film obtained by directly oxidizing a silicon substrate. Accordingly, the voltage to be used is a large voltage ranging from positive to negative one. In contrast, by storing charges in a plurality of dispersed regions, high reliability is achieved. Based on the high reliability, transfer of electrons is permitted through not only the oxide film obtained by directly thermally oxidizing a high reliability silicon substrate but also another oxide film deposited by CVD, or the like. In consequence, a device is controlled by electric potentials of the same polarity upon writing of data and upon erasing of data.
    Type: Grant
    Filed: October 5, 2004
    Date of Patent: May 16, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Taro Osabe, Tomoyuki Ishii
  • Publication number: 20060065920
    Abstract: Disclosed is a non-volatile semiconductor memory device that uses a inversion layer provided on a semiconductor substrate as a data line. The memory device can reduce variation of characteristics among memory cells and can reduce bit cost. A plurality of assist gates are formed in the upper part of a p-type well through a gate oxide film. In the upper part of an interlayer insulator that covers those assist gates are formed word lines that are used as control electrodes. The width of those word lines is, for example, 0.1 ?m, and each word line is separated from its adjacent word lines by a side wall spacer that is a silicon oxide film having a thickness of about 20 nm.
    Type: Application
    Filed: November 14, 2005
    Publication date: March 30, 2006
    Inventors: Tomoyuki Ishii, Taro Osabe, Hideaki Kurata, Takeshi Sakata
  • Publication number: 20050237786
    Abstract: A high integration dynamic random access memory is provided by this invention. Furthermore, a write method is provided such that cell size of two-and three-transistor gain cell memories is reduced. A dynamic memory incorporating a thin-channel transistor as the write element such that long data storage retention is achieved in the memory devices of this invention. A dynamic memory cell having low operating power and high density is also realized by this invention.
    Type: Application
    Filed: June 20, 2005
    Publication date: October 27, 2005
    Inventors: Bryan Atwood, Kazuo Yano, Tomoyuki Ishii, Taro Osabe, Kazumasa Yanagisawa, Takeshi Sakata
  • Patent number: 6949782
    Abstract: A high integration dynamic random access memory is provided by this invention. Furthermore, a write method is provided such that the cell size of two-and three-transistor gain cell memories is reduced. A dynamic memory incorporating a thin-channel transistor as the write element such that long data storage retention is achieved in the memory devices of this invention. A dynamic memory cell having low operating power and high density is also realized by this invention.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: September 27, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Bryan Atwood, Kazuo Yano, Tomoyuki Ishii, Taro Osabe, Kazumasa Yanagisawa, Takeshi Sakata
  • Publication number: 20050173751
    Abstract: A nonvolatile semiconductor memory device that uses inversion layers formed on a surface of its semiconductor substrate as data lines, which is capable of satisfying the requirements of suppressing both characteristic variation among memory cells and bit cost. In order to achieve the above object, in the memory device, a plurality of assist gates are formed so as to be embedded in a p-type well via a silicon oxide film, respectively and silicon nanocrystal grains of about 6 nm in average diameter used for storing information are formed without being in contact with one another. Then, a plurality of word lines are formed practically in a direction vertically to the assist gates and the space between adjacent those of the plurality of word lines is set under ½ of the width (gate length) of the word lines.
    Type: Application
    Filed: December 3, 2004
    Publication date: August 11, 2005
    Inventors: Tomoyuki Ishii, Toshiyuki Mine, Yoshitaka Sasago, Taro Osabe
  • Publication number: 20050056884
    Abstract: In a semiconductor flash memory required to have high reliability, injection and extraction of electrons must be performed through an oxide film obtained by directly oxidizing a silicon substrate. Accordingly, the voltage to be used is a large voltage ranging from positive to negative one. In contrast, by storing charges in a plurality of dispersed regions, high reliability is achieved. Based on the high reliability, transfer of electrons is permitted through not only the oxide film obtained by directly thermally oxidizing a high reliability silicon substrate but also another oxide film deposited by CVD, or the like. In consequence, a device is controlled by electric potentials of the same polarity upon writing of data and upon erasing of data.
    Type: Application
    Filed: October 5, 2004
    Publication date: March 17, 2005
    Inventors: Taro Osabe, Tomoyuki Ishii
  • Publication number: 20050052939
    Abstract: For providing a cheap semiconductor memory device with improving reliability by level of a cell, in the place of escaping from defects on memory cells electrically, through such as ECC, and further for providing a cell structure enabling scaling-down in the vertical direction with maintaining the reliability, in a semiconductor memory device, upon which high-speeded read-out operation is required, a charge storage region is constructed with particles made from a large number of semiconductor charge storage small regions, each being independent, thereby increasing the reliability by the cell level.
    Type: Application
    Filed: August 17, 2004
    Publication date: March 10, 2005
    Inventors: Taro Osabe, Tomoyuki Ishii, Kazuo Yano, Takashi Kabayashi
  • Publication number: 20050029681
    Abstract: Disclosed is a non-volatile semiconductor memory device that uses a inversion layer provided on a semiconductor substrate as a data line. The memory device can reduce variation of characteristics among memory cells and can reduce bit cost. A plurality of assist gates are formed in the upper part of a p-type well through a gate oxide film. In the upper part of an interlayer insulator that covers those assist gates are formed word lines that are used as control electrodes. The width of those word lines is, for example, 0.1 ?m, and each word line is separated from its adjacent word lines by a side wall spacer that is a silicon oxide film having a thickness of about 20 nm.
    Type: Application
    Filed: July 6, 2004
    Publication date: February 10, 2005
    Inventors: Tomoyuki Ishii, Taro Osabe, Hideaki Kurata, Takeshi Sakata
  • Patent number: 6849895
    Abstract: For providing a cheap semiconductor memory device with improving reliability by level of a cell, in the place of escaping from defects on memory cells electrically, through such as ECC, and further for providing a cell structure enabling scaling-down in the vertical direction with maintaining the reliability, in a semiconductor memory device, upon which high-speeded read-out operation is required, a charge storage region is constructed with particles made from a large number of semiconductor charge storage small regions, each being independent, thereby increasing the reliability by the cell level.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: February 1, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Taro Osabe, Tomoyuki Ishii, Kazuo Yano, Takashi Kobayashi
  • Patent number: 6815763
    Abstract: In a semiconductor flash memory required to have high reliability, injection and extraction of electrons must be performed through an oxide film obtained by directly oxidizing a silicon substrate. Accordingly, the voltage to be used is a large voltage ranging from positive to negative one. In contrast, by storing charges in a plurality of dispersed regions, high reliability is achieved. Based on the high reliability, transfer of electrons is permitted through not only the oxide film obtained by directly thermally oxidizing a high reliability silicon substrate but also another oxide film deposited by CVD, or the like. In consequence, a device is controlled by electric potentials of the same polarity upon writing of data and upon erasing of data.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: November 9, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Taro Osabe, Tomoyuki Ishii
  • Patent number: 6787835
    Abstract: A high integration dynamic random access memory is provided by this invention. Furthermore, a write method is provided such that the cell size of two- and three-transistor gain cell memories is reduced. A dynamic memory incorporating a thin-channel transistor as the write element such that long data storage retention is achieved in the memory devices of this invention. A dynamic memory cell having low operating power and high density is also realized by this invention.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: September 7, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Bryan Atwood, Kazuo Yano, Tomoyuki Ishii, Taro Osabe, Kazumasa Yanagisawa, Takeshi Sakata
  • Publication number: 20040164326
    Abstract: A high integration dynamic random access memory is provided by this invention. Furthermore, a write method is provided such that the cell size of two-and three-transistor gain cell memories is reduced. A dynamic memory incorporating a thin-channel transistor as the write element such that long data storage retention is achieved in the memory devices of this invention. A dynamic memory cell having low operating power and high density is also realized by this invention.
    Type: Application
    Filed: March 2, 2004
    Publication date: August 26, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Bryan Atwood, Kazuo Yano, Tomoyuki Ishii, Taro Osabe, Kazumasa Yanagisawa, Takeshi Sakata
  • Publication number: 20040084706
    Abstract: An object of the present invention is to provide a semiconductor memory device suitable for larger-capacity storage because of its ability to store 3 or more bits in one element and capable of a high-speed and high-efficiency write operation due to a reduced leakage current during the write operation and provide a fabrication method therefor. According to the present invention, each of elements has a source region, a drain region, a control gate, two charge storage regions, and one or more assist gates. During a write operation, source side injection writing is performed with respect to a write target element by using the assist gates, while adjacent elements are isolated by field isolation using the assist gates.
    Type: Application
    Filed: October 21, 2003
    Publication date: May 6, 2004
    Applicant: Renesas Technology Corp.
    Inventors: Taro Osabe, Tomoyuki Ishii, Takashi Kobayashi
  • Publication number: 20030227041
    Abstract: A high integration dynamic random access memory is provided by this invention. Furthermore, a write method is provided such that the cell size of two-and three-transistor gain cell memories is reduced. A dynamic memory incorporating a thin-channel transistor as the write element such that long data storage retention is achieved in the memory devices of this invention. A dynamic memory cell having low operating power and high density is also realized by this invention.
    Type: Application
    Filed: June 11, 2002
    Publication date: December 11, 2003
    Inventors: Bryan Atwood, Kazuo Yano, Tomoyuki Ishii, Taro Osabe, Kazumasa Yanagisawa, Takeshi Sakata