Patents by Inventor Mitsue Takahashi

Mitsue Takahashi 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: 11335783
    Abstract: A FeFET and a method of its manufacture are provided, the FeFET having a ferroelectric whose film thickness (dr) is made small and so nanofine as to range in: 59 nm<dr<150 nm, without impairing the data retention property of not less than 105 seconds and the data rewrite endurance property of not less than 108 times, of those that have hitherto been developed, and the FeFET allowing a memory window of 0.40 V or more when a sweep amplitude of the gate voltage is not more than 3.3 V.
    Type: Grant
    Filed: May 8, 2020
    Date of Patent: May 17, 2022
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, WACOM R&D CORPORATION
    Inventors: Shigeki Sakai, Mitsue Takahashi, Masaki Kusuhara, Masayuki Toda, Masaru Umeda, Yoshikazu Sasaki
  • Patent number: 11069713
    Abstract: A semiconductor memory element is provided including a laminated structure, in which a memory member and a conductor are superposed on a semiconductor substrate. The memory member has a bottom surface in contact with the semiconductor substrate, an upper surface in contact with the conductor, and side surfaces, which are in contact with and surrounded by a partition wall; the bottom surface of the memory member has a width of equal to or not more than 100 nm; a shortest distance between the conductor and the semiconductor substrate is twice or more of the width of the bottom surface of the memory member; the side surface of the memory member has a width, which is either the same as the width of the bottom surface and constant at any position above the bottom surface, or the widest at a position other than the bottom surface and above the bottom surface.
    Type: Grant
    Filed: July 3, 2017
    Date of Patent: July 20, 2021
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, WACOM
    Inventors: Mitsue Takahashi, Shigeki Sakai, Masaki Kusuhara, Masayuki Toda, Masaru Umeda, Yoshikazu Sasaki
  • Publication number: 20200279927
    Abstract: [Object] To provide a FeFET and a method of its manufacture, the FeFET having a ferroelectric whose film thickness (dr) is made small and so nanofine as to range in: 59 nm<dr<150, without impairing the data retention property of not less than 105 seconds and the data rewrite withstand property of not less than 108 times, of those that have hitherto been developed, and the FeFET allowing data to be written with a writing voltage whose absolute value is not more than 3.3 volts. [Means for Solving] In methods of making a device in which an insulator, a film made of constituent elements of a bismuth layered perovskite crystalline ferroelectric and a metal are sequentially formed in the indicated order on a semiconductor substrate and thereafter are annealed for ferroelectric crystallization, thereby preparing the device composed of the semiconductor, insulator, ferroelectric and metal, a method of making a semiconductor ferroelectric memory element in which the film is composed of Ca.
    Type: Application
    Filed: May 8, 2020
    Publication date: September 3, 2020
    Inventors: Shigeki SAKAI, Mitsue TAKAHASHI, Masaki KUSUHARA, Masayuki TODA, Masaru UMEDA, Yoshikazu SASAKI
  • Patent number: 10686043
    Abstract: [Object] To provide a FeFET and a method of its manufacture, the FeFET having a ferroelectric whose film thickness (dr) is made small and so nanofine as to range in: 59 nm<dr<150, without impairing the data retention property of not less than 105 seconds and the data rewrite withstand property of not less than 108 times, of those that have hitherto been developed, and the FeFET allowing data to be written with a writing voltage whose absolute value is not more than 3.3 volts. [Means for Solving] In methods of making a device in which an insulator, a film made of constituent elements of a bismuth layered perovskite crystalline ferroelectric and a metal are sequentially formed in the indicated order on a semiconductor substrate and thereafter are annealed for ferroelectric crystallization, thereby preparing the device composed of the semiconductor, insulator, ferroelectric and metal, a method of making a semiconductor ferroelectric memory element in which the film is composed of Ca.
    Type: Grant
    Filed: April 21, 2017
    Date of Patent: June 16, 2020
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, WACOM R&D CORPORATION
    Inventors: Shigeki Sakai, Mitsue Takahashi, Masaki Kusuhara, Masayuki Toda, Masaru Umeda, Yoshikazu Sasaki
  • Publication number: 20190273086
    Abstract: A semiconductor memory element is provided including a laminated structure, in which a memory member and a conductor are superposed on a semiconductor substrate. The memory member has a bottom surface in contact with the semiconductor substrate, an upper surface in contact with the conductor, and side surfaces, which are in contact with and surrounded by a partition wall; the bottom surface of the memory member has a width of equal to or not more than 100 nm; a shortest distance between the conductor and the semiconductor substrate is twice or more of the width of the bottom surface of the memory member; the side surface of the memory member has a width, which is either the same as the width of the bottom surface and constant at any position above the bottom surface, or the widest at a position other than the bottom surface and above the bottom surface.
    Type: Application
    Filed: July 3, 2017
    Publication date: September 5, 2019
    Applicants: National Institute of Advanced Industrial Science and Technology, WACOM R&D Corporation
    Inventors: Mitsue TAKAHASHI, Shigeki SAKAI, Masaki KUSUHARA, Masayuki TODA, Masaru UMEDA, Yoshikazu SASAKI
  • Patent number: 10192972
    Abstract: Provided is a ferroelectric field effect transistor (FeFET) which has a wide memory window even if the ferroelectric film thickness is 200 nm or less, and which has excellent data retention characteristics, pulse rewriting endurance and the like. An FeFET which has a structure wherein an insulating body (11) and a gate electrode conductor (4) are sequentially laminated in this order on a semiconductor base (10) that has a source region (12) and a drain region (13). The insulating body (11) is configured by laminating a first insulating body (1) and a second insulating body (2) in this order on the base (10), and the second insulating body (2) is mainly composed of an oxide of strontium, calcium, bismuth and tantalum.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: January 29, 2019
    Assignee: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Shigeki Sakai, Wei Zhang, Mitsue Takahashi
  • Publication number: 20180130909
    Abstract: A ferroelectric device and a manufacturing method are provided. While holding a nonvolatile memory retention capability and a multiple rewriting endurance as the distinctive features of a ferroelectric device, the disclosed ferroelectric device is wider in memory window and more adaptively made microfiner than a conventional ferroelectric device that has used a ferroelectric mainly constituted of Sr—Bi—Ta—O as an oxide of strontium, bismuth and tantalum. Directly on or with intermediary of an insulator on a semiconductor there are layered a first ferroelectric and a conductor to form a gate stack, the first ferroelectric being mainly constituted of Sr—Ca—Bi—Ta—O as an oxide of strontium, calcium, bismuth and tantalum and being built up by a metal organic vapor deposition technique from a suitable film-forming raw material. The gate stack is heat-treated to cause the first ferroelectric to develop its ferroelectricity.
    Type: Application
    Filed: August 11, 2017
    Publication date: May 10, 2018
    Inventors: Shigeki SAKAI, Mitsue TAKAHASHI, Masaki KUSUHARA, Masayuki TODA, Masaru UMEDA
  • Publication number: 20180006130
    Abstract: Provided is a ferroelectric field effect transistor (FeFET) which has a wide memory window even if the ferroelectric film thickness is 200 nm or less, and which has excellent data retention characteristics, pulse rewriting endurance and the like. An FeFET which has a structure wherein an insulating body (11) and a gate electrode conductor (4) are sequentially laminated in this order on a semiconductor base (10) that has a source region (12) and a drain region (13). The insulating body (11) is configured by laminating a first insulating body (1) and a second insulating body (2) in this order on the base (10), and the second insulating body (2) is mainly composed of an oxide of strontium, calcium, bismuth and tantalum.
    Type: Application
    Filed: August 29, 2017
    Publication date: January 4, 2018
    Inventors: Shigeki SAKAI, Wei ZHANG, Mitsue TAKAHASHI
  • Patent number: 9818869
    Abstract: A ferroelectric device and a manufacturing method are provided. While holding a nonvolatile memory retention capability and a multiple rewriting endurance as the distinctive features of a ferroelectric device, the disclosed ferroelectric device is wider in memory window and more adaptively made microfiner than a conventional ferroelectric device that has used a ferroelectric mainly constituted of Sr—Bi—Ta—O as an oxide of strontium, bismuth and tantalum. Directly on or with intermediary of an insulator on a semiconductor there are layered a first ferroelectric and a conductor to form a gate stack, the first ferroelectric being mainly constituted of Sr—Ca—Bi—Ta—O as an oxide of strontium, calcium, bismuth and tantalum and being built up by a metal organic vapor deposition technique from a suitable film-forming raw material. The gate stack is heat-treated to cause the first ferroelectric to develop its ferroelectricity.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: November 14, 2017
    Assignees: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, WACOM R&D CORPORATION
    Inventors: Shigeki Sakai, Mitsue Takahashi, Masaki Kusuhara, Masayuki Toda, Masaru Umeda
  • Publication number: 20170309488
    Abstract: [Object] To provide a FeFET and a method of its manufacture, the FeFET having a ferroelectric whose film thickness (dr) is made small and so nanofine as to range in: 59 nm<dr<150, without impairing the data retention property of not less than 105 seconds and the data rewrite withstand property of not less than 108 times, of those that have hitherto been developed, and the FeFET allowing data to be written with a writing voltage whose absolute value is not more than 3.3 volts. [Means for Solving] In methods of making a device in which an insulator, a film made of constituent elements of a bismuth layered perovskite crystalline ferroelectric and a metal are sequentially formed in the indicated order on a semiconductor substrate and thereafter are annealed for ferroelectric crystallization, thereby preparing the device composed of the semiconductor, insulator, ferroelectric and metal, a method of making a semiconductor ferroelectric memory element in which the film is composed of Ca.
    Type: Application
    Filed: April 21, 2017
    Publication date: October 26, 2017
    Inventors: Shigeki SAKAI, Mitsue TAKAHASHI, Masaki KUSUHARA, Masayuki TODA, Masaru UMEDA, Yoshikazu SASAKI
  • Patent number: 9780186
    Abstract: Provided is a ferroelectric field effect transistor (FeFET) which has a wide memory window even if the ferroelectric film thickness is 200 nm or less, and which has excellent data retention characteristics, pulse rewriting endurance and the like. An FeFET which has a structure wherein an insulating body (11) and a gate electrode conductor (4) are sequentially laminated in this order on a semiconductor base (10) that has a source region (12) and a drain region (13). The insulating body (11) is configured by laminating a first insulating body (1) and a second insulating body (2) in this order on the base (10), and the second insulating body (2) is mainly composed of an oxide of strontium, calcium, bismuth and tantalum.
    Type: Grant
    Filed: May 30, 2013
    Date of Patent: October 3, 2017
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Shigeki Sakai, Wei Zhang, Mitsue Takahashi
  • Publication number: 20160247932
    Abstract: A ferroelectric device and a manufacturing method are provided. While holding a nonvolatile memory retention capability and a multiple rewriting endurance as the distinctive features of a ferroelectric device, the disclosed ferroelectric device is wider in memory window and more adaptively made microfiner than a conventional ferroelectric device that has used a ferroelectric mainly constituted of Sr—Bi—Ta—O as an oxide of strontium, bismuth and tantalum. Directly on or with intermediary of an insulator on a semiconductor there are layered a first ferroelectric and a conductor to form a gate stack, the first ferroelectric being mainly constituted of Sr—Ca—Bi—Ta—O as an oxide of strontium, calcium, bismuth and tantalum and being built up by a metal organic vapor deposition technique from a suitable film-forming raw material. The gate stack is heat-treated to cause the first ferroelectric to develop its ferroelectricity.
    Type: Application
    Filed: July 24, 2014
    Publication date: August 25, 2016
    Inventors: Shigeki SAKAI, Mitsue TAKAHASHI, Masaki KUSUHARA, Masayuki TODA, Masaru UMEDA
  • Publication number: 20150171183
    Abstract: Provided is a ferroelectric field effect transistor (FeFET) which has a wide memory window even if the ferroelectric film thickness is 200 nm or less, and which has excellent data retention characteristics, pulse rewriting endurance and the like. An FeFET which has a structure wherein an insulating body (11) and a gate electrode conductor (4) are sequentially laminated in this order on a semiconductor base (10) that has a source region (12) and a drain region (13). The insulating body (11) is configured by laminating a first insulating body (1) and a second insulating body (2) in this order on the base (10), and the second insulating body (2) is mainly composed of an oxide of strontium, calcium, bismuth and tantalum.
    Type: Application
    Filed: May 30, 2013
    Publication date: June 18, 2015
    Inventors: Shigeki Sakai, Wei Zhang, Mitsue Takahashi
  • Patent number: 8159873
    Abstract: There is provided a semiconductor integrated circuit including a state detection enhancement circuit which includes an input terminal and an output terminal and has a function of generating an electric potential of a magnitude capable of performing nonvolatile memory writing into a nonvolatile memory circuit based on an electric potential input to the input terminal and outputting the electric potential of the magnitude to the output terminal, and the nonvolatile memory circuit has a nonvolatile memory function and an input terminal of the nonvolatile memory circuit is connected to the output of the state detection enhancement circuit.
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: April 17, 2012
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Mitsue Takahashi, Shigeki Sakai
  • Patent number: 8139388
    Abstract: This invention has the purpose of providing a nonvolatile semiconductor storage device which is capable of entering multivalued storage in a FeFET unit without requiring preparation of a plurality of voltage sources. The nonvolatile semiconductor storage device is provided with multivalued ferroelectric memory cells which impart varied quantities of polarization to a ferroelectric material by applying pulse voltages having one and the same height and varied widths and consequently produce varied states of storage in conformity with the varied quantities of polarization.
    Type: Grant
    Filed: September 23, 2009
    Date of Patent: March 20, 2012
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Mitsue Takahashi, Shigeki Sakai, Shouyu Wang, Ken Takeuchi
  • Patent number: 8081499
    Abstract: A field-effect transistor for nonvolatile memory holding use and a field-effect transistor for logical operation use are manufactured in the same structure on the same semiconductor substrate without separately providing manufacturing processes for the field-effect transistors for the two uses. Both a memory circuit and a logic circuit of a semiconductor integrated circuit are composed of n-channel and p-channel field-effect transistors including a memory holding material in a gate insulating structure. A logical operation state, a memory writing state and a nonvolatile memory holding state are electrically switched by controlling the level and application timing of a voltage to be applied between a gate conductor and a substrate region of the n-channel and p-channel field-effect transistors including the memory holding material in the gate insulating structure.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: December 20, 2011
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Mitsue Takahashi, Shigeki Sakai
  • Publication number: 20110038201
    Abstract: There is provided a semiconductor integrated circuit including a state detection enhancement circuit which includes an input terminal and an output terminal and has a function of generating an electric potential of a magnitude capable of performing nonvolatile memory writing into a nonvolatile memory circuit based on an electric potential input to the input terminal and outputting the electric potential of the magnitude to the output terminal, and the nonvolatile memory circuit has a nonvolatile memory function and an input terminal of the nonvolatile memory circuit is connected to the output of the state detection enhancement circuit.
    Type: Application
    Filed: October 29, 2007
    Publication date: February 17, 2011
    Applicant: NATIONAL INSTITUTE OF ADVANCED IND.SCI AND TECH
    Inventors: Mitsue Takahashi, Shigeki Sakai
  • Publication number: 20100073988
    Abstract: This invention has the purpose of providing a nonvolatile semiconductor storage device which is capable of entering multivalued storage in a FeFET unit without requiring preparation of a plurality of voltage sources. The nonvolatile semiconductor storage device is provided with multivalued ferroelectric memory cells which impart varied quantities of polarization to a ferroelectric material by applying pulse voltages having one and the same height and varied widths and consequently produce varied states of storage in conformity with the varied quantities of polarization.
    Type: Application
    Filed: September 23, 2009
    Publication date: March 25, 2010
    Applicant: Nat Inst of Adv Industrial Sci and Tech
    Inventors: Mitsue TAKAHASHI, Shigeki Sakai, Shouyu Wang, Ken Takeuchi
  • Publication number: 20090059646
    Abstract: A field-effect transistor for nonvolatile memory holding use and a field-effect transistor for logical operation use are manufactured in the same structure on the same semiconductor substrate without separately providing manufacturing processes for the field-effect transistors for the two uses. Both a memory circuit and a logic circuit of a semiconductor integrated circuit are composed of n-channel and p-channel field-effect transistors including a memory holding material in a gate insulating structure. A logical operation state, a memory writing state and a nonvolatile memory holding state are electrically switched by controlling the level and application timing of a voltage to be applied between a gate conductor and a substrate region of the n-channel and p-channel field-effect transistors including the memory holding material in the gate insulating structure.
    Type: Application
    Filed: April 13, 2006
    Publication date: March 5, 2009
    Applicant: NATIONAL INSTITUTE OF ADVANCED IND. SCI & TECH
    Inventors: Mitsue Takahashi, Shigeki Sakai
  • Patent number: 6445633
    Abstract: A read amplifier circuit includes an equalize start circuit. Based on a preamp enable signal PAE and an equalize signal IOEQ, the equalize start circuit generates an equalize start signal EQ for starting equalization at the timing when the preamp enable signal PAE is activated. Simultaneously with activation of a preamplifier by the preamp enable signal PAE, a pair of read lines GIOR and /GIOR is cut off from the preamplifier, and a P channel MOS transistor starts equalization of the pair of read lines GIOR and /GIOR. In this way, it is possible to start equalization of the paired read lines at the same time that the output signal is supplied to the preamplifier.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: September 3, 2002
    Assignees: Mitsubishi Kabushiki Kaisha, Mitsubishi Electric Engineering Company Limited
    Inventors: Mitsue Takahashi, Hiroaki Tanizaki