Patents by Inventor Takamasa Satoh

Takamasa Satoh 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: 7919750
    Abstract: An electron gun includes an electron source configured to emit electrons. The electron source includes an electron emission region configured to emit the electrons and an electron emission restrictive region configured to restrict emission of the electrons. The electron emission restrictive region is located on a side surface of the electron source except an electron emission surface on a tip of the electron source and is covered with a different material from the electron source. The electron gun emits thermal field-emitted electrons by applying an electric field to the tip while maintaining a sufficiently low temperature to avoid sublimation of a material of the electron source. The material of the electron source may be lanthanum hexaboride (LaB6) or cerium hexaboride (CeB6). The electron emission restrictive region may be covered with carbon.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: April 5, 2011
    Assignees: Advantest Corporation, Denki Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Yasuda, Takeshi Haraguchi, Yoshihisa Ooae, Takamasa Satoh, Yoshinori Terui, Seiichi Sakawa, Ryozo Nonogaki
  • Patent number: 7777202
    Abstract: An electron beam exposure apparatus includes: an electron gun for generating an electron beam; a deflector for deflecting the electron beam; a wafer stage; a stage position detector for detecting a position of the wafer stage; and a stage position computing unit for calculating a movement velocity of the wafer stage. On a basis of the movement velocity, the stage position computing unit calculates an amount of positional change of the wafer stage with respect to an interpolation time, and subsequently calculates an amount of positional movement of the wafer stage by sequentially adding the amount of positional change to the position of the wafer stage in synchronism with the interpolation time. Thus, the stage position computing unit calculates an amount of deflection of the electron beam corresponding to the amount of the positional movement of the wafer stage.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: August 17, 2010
    Assignee: Advantest Corp.
    Inventors: Takamasa Satoh, Yoshihisa Ooae
  • Patent number: 7557357
    Abstract: The present invention is related to a D/A conversion device, it is provided with a first D/A conversion circuit which receives input of digital data composed of plural bits and outputs a corresponding electric output signal, and a second D/A conversion circuit which receives input of a correction code for the digital data and which outputs a corresponding electric correction signal, wherein the first and second D/A conversion circuits are connected to each other at their respective output terminals so that the electric output signal is corrected by the electric correction signal. The D/A conversion device comprises: storing means 105 for storing correction codes each for one bit of the digital data, the correction codes being determined in correlation with the first D/A conversion circuit 11; and calculating means 107 for performing serial entry and addition of the correction codes each for one bit of the digital data, and outputting a correction code for all bits of the digital data.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: July 7, 2009
    Assignees: Advantest Corporation, Hitachi Information & Communication Engineering, Ltd.
    Inventors: Takamasa Satoh, Koichi Hidaka, Ryozo Yoshino
  • Publication number: 20080315089
    Abstract: An electron gun includes an electron source configured to emit electrons. The electron source includes an electron emission region configured to emit the electrons and an electron emission restrictive region configured to restrict emission of the electrons. The electron emission restrictive region is located on a side surface of the electron source except an electron emission surface on a tip of the electron source and is covered with a different material from the electron source. The electron gun emits thermal field-emitted electrons by applying an electric field to the tip while maintaining a sufficiently low temperature to avoid sublimation of a material of the electron source. The material of the electron source may be lanthanum hexaboride (LaB6) or cerium hexaboride (CeB6). The electron emission restrictive region may be covered with carbon.
    Type: Application
    Filed: May 7, 2008
    Publication date: December 25, 2008
    Inventors: Hiroshi Yasuda, Takeshi Haraguchi, Yoshihisa Ooae, Takamasa Satoh, Yoshinori Terui, Seiichi Sakawa, Ryozo Nonogaki
  • Publication number: 20080277598
    Abstract: An electron beam exposure apparatus includes: an electron gun for generating an electron beam; a deflector for deflecting the electron beam; a wafer stage; a stage position detector for detecting a position of the wafer stage; and a stage position computing unit for calculating a movement velocity of the wafer stage. On a basis of the movement velocity, the stage position computing unit calculates an amount of positional change of the wafer stage with respect to an interpolation time, and subsequently calculates an amount of positional movement of the wafer stage by sequentially adding the amount of positional change to the position of the wafer stage in synchronism with the interpolation time. Thus, the stage position computing unit calculates an amount of deflection of the electron beam corresponding to the amount of the positional movement of the wafer stage.
    Type: Application
    Filed: March 28, 2007
    Publication date: November 13, 2008
    Inventors: Takamasa Satoh, Yoshihisa Ooae
  • Publication number: 20080054185
    Abstract: The present invention is related to a D/A conversion device, it is provided with a first D/A conversion circuit which receives input of digital data composed of plural bits and outputs a corresponding electric output signal, and a second D/A conversion circuit which receives input of a correction code for the digital data and which outputs a corresponding electric correction signal, wherein the first and second D/A conversion circuits are connected to each other at their respective output terminals so that the electric output signal is corrected by the electric correction signal. The D/A conversion device comprises: storing means 105 for storing correction codes each for one bit of the digital data, the correction codes being determined in correlation with the first D/A conversion circuit 11; and calculating means 107 for performing serial entry and addition of the correction codes each for one bit of the digital data, and outputting a correction code for all bits of the digital data.
    Type: Application
    Filed: March 28, 2007
    Publication date: March 6, 2008
    Inventors: Takamasa Satoh, Koichi Hidaka, Ryozo Yoshino
  • Patent number: 6727658
    Abstract: An electron beam generating apparatus for generating a plurality of electron beams, which includes: a plurality of cathodes for generating thermoelectrons; a cathode power supply unit for applying negative voltage to the cathodes so as to emit the thermoelectrons from the cathodes; a plurality of grids, which correspond to the plurality of cathodes respectively, for focusing the thermoelectrons emitted from each of the plurality of cathodes, and shaping the plurality of electron beams; and an insulator on which the plurality of cathodes and the plurality of grids are attached.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: April 27, 2004
    Assignee: Advantest Corporation
    Inventors: Yoshihisa Ooae, Yoichi Shimizu, Takamasa Satoh, Takeshi Haraguchi
  • Patent number: 6646275
    Abstract: A charged particle beam exposure method includes the steps of creating dot pattern data indicative of a pattern to be exposed, storing the dot pattern data in a first storage device having a first access speed, transferring the dot pattern data from the first storage device to a second storage device having a second, higher access speed, reading the dot pattern data out from the second storage device, and producing a plurality of charged particle beams in response to the dot pattern data read out from the second storage device by means of a blanking aperture array, wherein the blanking aperture array includes a plurality of apertures each causing turning-on and turning-off of a changed particle beam pertinent to the aperture in response to the dot pattern data.
    Type: Grant
    Filed: September 11, 2002
    Date of Patent: November 11, 2003
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Tomohiko Abe, Soichiro Arai, Shigeru Maruyama, Hiroshi Yasuda, Kenichi Miyazawa, Junichi Kai, Takamasa Satoh, Keiichi Betsui, Hideki Nasuno
  • Publication number: 20030155522
    Abstract: An electron beam generating apparatus for generating a plurality of electron beams, which includes: a plurality of cathodes for generating thermoelectrons; a cathode power supply unit for applying negative voltage to the cathodes so as to emit the thermoelectrons from the cathodes; a plurality of grids, which correspond to the plurality of cathodes respectively, for focusing the thermoelectrons emitted from each of the plurality of cathodes, and shaping the plurality of electron beams; and an insulator on which the plurality of cathodes and the plurality of grids are attached.
    Type: Application
    Filed: March 7, 2003
    Publication date: August 21, 2003
    Applicant: ADVANTEST CORPORATION
    Inventors: Yoshihisa Ooae, Yoichi Shimizu, Takamasa Satoh, Takeshi Haraguchi
  • Publication number: 20030071231
    Abstract: An electron beam exposure apparatus of high accuracy and high throughput despite a change in the ambient atmospheric pressure has been disclosed. In an electron beam exposure apparatus, and an electron beam exposing method using it, which comprises a vacuum chamber that accommodates a column and a stage and internally contains a vacuum, the atmospheric pressure in the environment, in which the electron beam apparatus is installed, is detected and the irradiation position of the electron beam on a specimen or the focal position of the electron beam with respect to the surface of the specimen is corrected according to the detected atmospheric pressure.
    Type: Application
    Filed: September 23, 2002
    Publication date: April 17, 2003
    Inventors: Takeshi Haraguchi, Takamasa Satoh
  • Publication number: 20030025088
    Abstract: A charged particle beam exposure method includes the steps of creating dot pattern data indicative of a pattern to be exposed, storing the dot pattern data in a first storage device having a first access speed, transferring the dot pattern data from the first storage device to a second storage device having a second, higher access speed, reading the dot pattern data out from the second storage device, and producing a plurality of charged particle beams in response to the dot pattern data read out from the second storage device by means of a blanking aperture array, wherein the blanking aperture array includes a plurality of apertures each causing turning-on and turning-off of a changed particle beam pertinent to the aperture in response to the dot pattern data.
    Type: Application
    Filed: September 11, 2002
    Publication date: February 6, 2003
    Applicant: Fujitsu Limited
    Inventors: Yoshihisa Oae, Tomohiko Abe, Soichiro Arai, Shigeru Maruyama, Hiroshi Yasuda, Kenichi Miyazawa, Junichi Kai, Takamasa Satoh, Keiichi Betsui, Hideki Nasuno
  • Patent number: 6486479
    Abstract: A charged particle beam exposure method including the steps of creating dot pattern data indicative of a pattern to be exposed, storing the dot indicative of a pattern to be exposed, storing the dot pattern data in a first storage device having a first access speed, transferring the dot pattern data from the first storage device to a second storage device having a second, higher access speed, reading the dot pattern data out from the second storage device; and producing a plurality of charged particle beams in response to the dot pattern data read out from the second storage device by means of a blanking aperture array. The blanking aperture array includes a plurality of apertures each causing turning-on and turning-off of a changed particle beam pertinent to the aperture in response to the dot pattern data.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: November 26, 2002
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Tomohiko Abe, Soichiro Arai, Shigeru Maruyama, Hiroshi Yasuda, Kenichi Miyazawa, Junichi Kai, Takamasa Satoh, Keiichi Betsui, Hideki Nasuno
  • Publication number: 20010013581
    Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.
    Type: Application
    Filed: April 6, 2001
    Publication date: August 16, 2001
    Inventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa
  • Patent number: 6252344
    Abstract: An electron gun, preferably a four-pole electron gun, used in an electron beam exposure apparatus is formed by: a cathode for emitting an electron beam when supplying a negative and high-accelerated voltage; a first grid provided downstream of the cathode for focusing a crossover image of the electron beam when supplying a voltage which becomes a reverse bias for the cathode, and the cathode and the first grid being arranged at a high voltage side of a high voltage insulator; an anode for collecting the electron beam which passes through the first grid, and being arranged at a low voltage side of the high voltage insulator; and a second grid provided at the high voltage side of the high voltage insulator and between the first grid and the anode, and having an aperture for limiting an amount of the electron beam passing therethrough. A voltage which becomes a forward bias for the cathode is supplied to the second grid, and the crossover image is focused at the aperture of the second grid.
    Type: Grant
    Filed: June 17, 1999
    Date of Patent: June 26, 2001
    Assignee: Advantest Corporation
    Inventors: Yoshihisa Ooae, Takamasa Satoh, Akio Yamada, Hiroshi Yasuda
  • Patent number: 6242751
    Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.
    Type: Grant
    Filed: July 15, 1999
    Date of Patent: June 5, 2001
    Assignee: Fujitsu Limited
    Inventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa
  • Patent number: 6188074
    Abstract: A charged particle beam exposure apparatus of the BAA type is disclosed, which improves the transmission rate of at least a signal transmission path leading from a blanking aperture array (BAA) control circuit to at least a blanking electrode and has an increased BAA driving speed. The impedance of the signal transmission path leading from the driver of the BAA control circuit to the BAA electrode is rendered to coincide with the output impedance of the driver of the BAA control circuit. Further, an auxiliary transmission path is provided for leading the signal transmission path inside a column outside of the column, and terminates with a resistor having the same impedance with the transmission impedance, thereby matching the impedance of the signal transmission path.
    Type: Grant
    Filed: December 10, 1998
    Date of Patent: February 13, 2001
    Assignee: Advantest Corporation
    Inventors: Takamasa Satoh, Soichiro Arai
  • Patent number: 6118129
    Abstract: A method for exposing an exposure pattern on an object by a charged particle beam, including the steps of: shaping a charged particle beam into a plurality of charged particle beam elements in response to first bitmap data indicative of an exposure pattern, such that the plurality of charged particle beam elements are selectively turned off in response to the first bitmap data; focusing the charged particle beam elements upon a surface of an object; and scanning the surface of the object by the charged particle beam elements; the step of shaping including the steps of: expanding pattern data of said exposure pattern into second bitmap data having a resolution of n times (n.gtoreq.2) as large as, and m times (m.gtoreq.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: September 12, 2000
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Tomohiko Abe, Soichiro Arai, Shigeru Maruyama, Hiroshi Yasuda, Kenichi Miyazawa, Junichi Kai, Takamasa Satoh, Keiichi Betsui, Hideki Nasuno
  • Patent number: 6057907
    Abstract: Before figure data are expanded into a bitmap, a checksum is calculated in unit of bitmap data corresponding to a cell stripe of scanning over which continuous exposure is possible. When the checksum is calculated after expanding the data into the bitmap, the interim calculation result of refocus values is used. In exposure, exposing k number of sub rectangular areas by repeating a sub scanning k number of times, jumping a deflection by a main deflector toward an center of remaining sub rectangular areas whose number is (p-k) inside a main rectangular areas and exposing remained (p-k) number of the sub rectangular areas by repeating the sub scanning (p-k) times after the jumping is settled. In an amplifier & low pass filter for supplying a drive voltage to a sub deflector, the cutoff frequency is lowed during flyback in a sawtooth waveform without changing an amplification factor.
    Type: Grant
    Filed: August 12, 1998
    Date of Patent: May 2, 2000
    Assignee: Fujitsu Limited
    Inventors: Takamasa Satoh, Soichiro Arai, Kenichi Miyazawa, Yoshihisa Ooaeh, Junichi Kai, Hiroshi Yasuda
  • Patent number: 5977548
    Abstract: A charged particle beam exposure method including steps of creating dot pattern data indicative of a pattern to be exposed, storing the dot pattern data in a first storage device having a first access speed, transferring the dot pattern data from the first storage device to a second storage device having a second, higher access speed, reading the dot pattern data out from the second storage device, and producing a plurality of charged particle beams in response to the dot pattern data read out from the second storage device by means of a blanking aperture array. The blanking aperture array includes a plurality of apertures each causing turning-on and turning-off of a changed particle beam pertinent to the aperture in response to the dot pattern data.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: November 2, 1999
    Assignee: Fujitsu Limited
    Inventors: Yoshihisa Oae, Tomohiko Abe, Soichiro Arai, Shigeru Maruyama, Hiroshi Yasuda, Kenichi Miyazawa, Junichi Kai, Takamasa Satoh, Keiichi Betsui, Hideki Nasuno
  • Patent number: 5969365
    Abstract: A method of exposing a wafer to a charged-particle beam by directing to the wafer the charged-particle beam deflected by a deflector includes the steps of arranging a plurality of first marks at different heights, focusing the charged-particle beam on each of the first marks by using a focus coil provided above the deflector, obtaining a focus distance for each of the first marks, obtaining deflection-efficiency-correction coefficients for each of the first marks, and using linear functions of the focus distance for approximating the deflection-efficiency-correction coefficients to obtain the deflection-efficiency-correction coefficients for an arbitrary value of the focus distance. A device for carrying out the method is also set forth.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: October 19, 1999
    Assignee: Fujitsu Limited
    Inventors: Akio Takemoto, Yoshihisa Ooaeh, Tomohiko Abe, Hiroshi Yasuda, Takamasa Satoh, Hideki Nasuno, Hidefumi Yabara, Kenichi Kawakami, Kiichi Sakamoto, Tomohiro Sakazaki, Isamu Seto, Masami Takigawa, Tatsuro Ohkawa