Patents by Inventor Yasunari Sohda

Yasunari Sohda 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: 20150041648
    Abstract: Pattern critical dimension measurement equipment includes an electron source configured to generate a primary electron beam, a deflector configured to deflect the primary electron beam emitted from the electron source, a focusing lens configured to focus the primary electron beam deflected by the deflector, a decelerator configured to decelerate the primary electron beam that irradiates the sample, a first detector located between the electron source and the focusing lens, the first detector being configured to detect electrons at part of azimuths of electrons generated from the sample upon irradiation of the sample with the primary electron beam, and a second detector located between the electron source and the first detector, the second detector being configured to detect electrons at substantially all azimuths of the electrons generated from the sample.
    Type: Application
    Filed: August 9, 2014
    Publication date: February 12, 2015
    Inventors: Kaori Shirahata, Yasunari Sohda, Makoto Sakakibara, Daisuke Bizen, Hajime Kawano, Hideyuki Kazumi
  • Publication number: 20150034836
    Abstract: To improve the efficiency of generation of chromatic aberrations of an energy filter for reducing energy distribution. Mounted are an energy filter for primary electrons, the energy filter having a beam slit and a pair of a magnetic deflector and an electrostatic deflector that are superimposed with each other. An electron lens is arranged between the beam slit and the pair of the magnetic deflector and the electrostatic deflector.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 5, 2015
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Takafumi Miwa, Hajime Kawano
  • Publication number: 20140339425
    Abstract: A scanning electron beam device having: a deflector (5) for deflecting an electron beam (17) emitted from an electron source (1); an objective lens (7) for causing the electron beam to converge; a retarding electrode; a stage (9) for placing a wafer (16); and a controller (15); wherein the stage can be raised and lowered. In the low acceleration voltage region, the controller performs rough adjustment and fine adjustment of the focus in relation to the variation in the height of the wafer using electromagnetic focusing performed through excitation current adjustment of the objective lens. In the high acceleration voltage region, the controller performs rough adjustment of the focus in relation to the variation in the height of the wafer by mechanical focusing performed through raising and lowering of the stage, and performs fine adjustment by electrostatic focusing performed through adjustment of the retarding voltage.
    Type: Application
    Filed: November 26, 2012
    Publication date: November 20, 2014
    Inventors: Tasuku Yano, Yasunari Sohda, Muneyuki Fukuda, Katsunori Onuki, Hajime Kawano, Naomasa Suzuki
  • Publication number: 20140299769
    Abstract: To provide a scanning electron microscope that can detect reflected electrons of any emission angle, the scanning electron microscope, which obtains an image by detecting electrons from a sample (19) has: a control electrode (18) that discriminates between secondary electrons from the sample (19) and reflected electrons; a secondary electron conversion electrode (13) that generates secondary electrons by the impact of reflected electrons; a withdrawing electrode (12) that withdraws those secondary electrons; an energy filter (11) that discriminates between the secondary electrons withdrawn and electrons reflected from the sample (19); and a control calculation means (36) that selects a combination of voltages applied to the secondary electron conversion electrode (13), the withdrawing electrode (12), and energy filter (11).
    Type: Application
    Filed: September 27, 2012
    Publication date: October 9, 2014
    Inventors: Nobuhiro Okai, Yasunari Sohda, Ritsuo Fukaya, Zhigang Wang
  • Patent number: 8816277
    Abstract: An amount of pattern position displacement between observation images acquired by irradiating from two different directions is changed depending on beam deflection for moving an image acquisition position. In a pattern evaluation method that measures astigmatic difference or focus position displacement having a small amount of dose at a high speed using parallax caused by the tilted beam, a correction value obtained in advance by measurement is reflected in an amount of pattern position displacement between observation images obtained by irradiating from at least two different directions and generated in accordance with the amount of beam deflection for moving an image acquisition position. A processing unit calculates an amount of correction of an amount of pattern position displacement depending on beam deflection of a beam deflecting unit for moving an image acquisition position on the sample at a high speed.
    Type: Grant
    Filed: July 26, 2010
    Date of Patent: August 26, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Muneyuki Fukuda, Toru Yamanashi
  • Patent number: 8766183
    Abstract: The astigmatism control processing time is decreased to 1 second or less by improving the astigmatic difference measurement accuracy. A charged particle beam device includes: a stage on which a sample is loaded; a transport mechanism which carries the sample onto the stage; a charged particle beam optical system which irradiates the sample on the stage with a charged particle beam and detects secondary charged particles generated from the sample; and a controller which determines setup parameters for the charged particle beam optical system and controls the charged particle beam optical system. The controller registers and holds electro-optical system setup parameters for irradiation with a beam tilted from a normal line on the sample as the charged particle beam, compares observation images obtained by the tilted beam, measures the amount and direction of movement and calculates the amount of astigmatism correction from the amount of movement and the direction.
    Type: Grant
    Filed: September 10, 2009
    Date of Patent: July 1, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Muneyuki Fukuda, Hiromasa Yamanashi, Yasunari Sohda
  • Patent number: 8742342
    Abstract: A scanning electron microscope suppresses a beam drift by reducing charging on a sample surface while suppressing resolution degradation upon observation of an insulator sample. An electron microscope includes an electron source and an objective lens that focuses an electron beam emitted from the electron source, which provides an image using a secondary signal generated from the sample irradiated with the electron beam. A magnetic body with a continuous structure and an inside diameter larger than an inside diameter of an upper pole piece that forms the objective lens is provided between the objective lens and the sample.
    Type: Grant
    Filed: November 1, 2010
    Date of Patent: June 3, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Nobuhiro Okai, Yasunari Sohda
  • Patent number: 8735814
    Abstract: The electron beam device includes a source of electrons and an objective deflector. The electron beam device obtains an image on the basis of signals of secondary electrons, etc. which are emitted from a material by an electron beam being projected. The electron beam device further includes a bias chromatic aberration correction element, further including an electromagnetic deflector which is positioned closer to the source of the electrons than the objective deflector, and an electrostatic deflector which has a narrower interior diameter than the electromagnetic deflector, is positioned within the electromagnetic deflector such that the height-wise position from the material overlaps with the electromagnetic deflector, and is capable of applying an offset voltage. It is thus possible to provide an electron beam device with which it is possible to alleviate geometric aberration (parasitic aberration) caused by deflection and implement deflection over a wide field of view with high resolution.
    Type: Grant
    Filed: October 5, 2011
    Date of Patent: May 27, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Tasuku Yano, Muneyuki Fukuda, Noritsugu Takahashi
  • Patent number: 8704175
    Abstract: Provided is a scanning electron microscope equipped with a high-speed and high-precision astigmatism measuring means to be used when both astigmatism generated by an electron-beam column and astigmatism generated from the surroundings of a measuring sample exist. This scanning electron microscope is characterized in controlling an astigmatism corrector (201) with high-speed and high-precision, to correct the astigmatism, by using both a method of obtaining the astigmatism from the qualities of two-dimensional images to be acquired upon changing the intensity of the astigmatism corrector (201), and a method of measuring the astigmatism from the change in the position displacement of an electron beam that occurs when the electron beam is tilted using a tilt deflector (202).
    Type: Grant
    Filed: August 26, 2011
    Date of Patent: April 22, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Yasunari Sohda, Muneyuki Fukuda, Takeyoshi Ohashi, Osamu Komuro, Toru Yamanashi
  • Patent number: 8637820
    Abstract: Provided is a high-resolution scanning electron microscope with minimal aberration, and equipped with an electro-optical configuration that can form a tilted beam having wide-angle polarization and a desired angle, without interfering with an electromagnetic lens. In the scanning electron microscope, an electromagnetic deflector (201) is disposed above a magnetic lens (207), and a control electrode (202) that accelerates or decelerates electrons is provided so at to overlap (in such a manner that the height positions overlap with respect to the vertical direction) with the electromagnetic deflector (201). In wide field polarization, electrodes are accelerated, and in tilted beam formation, electrons are decelerated.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: January 28, 2014
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Kaori Shirahata, Keiichiro Hitomi
  • Patent number: 8575547
    Abstract: The present invention provides an electron beam measurement technique for measuring the shapes or sizes of portions of patterns on a sample, or detecting a defect or the like. An electron beam measurement apparatus has a unit for irradiating the patterns delineated on a substrate by a multi-exposure method, and classifying the patterns in an acquired image into multiple groups according to an exposure history record. The exposure history record is obtained based on brightness of the patterns and a difference between white bands of the patterns.
    Type: Grant
    Filed: December 30, 2010
    Date of Patent: November 5, 2013
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Yasunari Sohda, Shoji Hotta, Shinji Okazaki, Muneyuki Fukuda
  • Publication number: 20130270435
    Abstract: The electron beam device includes a source of electrons and an objective deflector. The electron beam device obtains an image on the basis of signals of secondary electrons, etc. which are emitted from a material by an electron beam being projected. The electron beam device further includes a bias chromatic aberration correction element, further including an electromagnetic deflector which is positioned closer to the source of the electrons than the objective deflector, and an electrostatic deflector which has a narrower interior diameter than the electromagnetic deflector, is positioned within the electromagnetic deflector such that the height-wise position from the material overlaps with the electromagnetic deflector, and is capable of applying an offset voltage. It is thus possible to provide an electron beam device with which it is possible to alleviate geometric aberration (parasitic aberration) caused by deflection and implement deflection over a wide field of view with high resolution.
    Type: Application
    Filed: October 5, 2011
    Publication date: October 17, 2013
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Tasuku Yano, Muneyuki Fukuda, Noritsugu Takahashi
  • Publication number: 20130264479
    Abstract: In order that a displacement between patterns of different heights, formed on a sample in a plurality of different pattern-forming steps, can be measured at fixed throughput and with high accuracy, correspondence between parameters of lenses and beam deflector of an electron optical system and an angle of incidence of a beam upon the sample is recorded as data, then a correction value for the amount of displacement or edge positions is calculated, and a true amount of displacement is calculated from the correction value and an image under observation.
    Type: Application
    Filed: April 3, 2013
    Publication date: October 10, 2013
    Inventors: Atsuko YAMAGUCHI, Yasunari SOHDA, Tatsuya MAEDA, Osamu NASU, Hiroki KAWADA
  • Publication number: 20130175447
    Abstract: Provided is a scanning electron microscope equipped with a high-speed and high-precision astigmatism measuring means to be used when both astigmatism generated by an electron-beam column and astigmatism generated from the surroundings of a measuring sample exist. This scanning electron microscope is characterized in controlling an astigmatism corrector (201) with high-speed and high-precision, to correct the astigmatism, by using both a method of obtaining the astigmatism from the qualities of two-dimensional images to be acquired upon changing the intensity of the astigmatism corrector (201), and a method of measuring the astigmatism from the change in the position displacement of an electron beam that occurs when the electron beam is tilted using a tilt deflector (202).
    Type: Application
    Filed: August 26, 2011
    Publication date: July 11, 2013
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Yasunari Sohda, Hiromasa Yamanashi, Muneyuki Fukuda, Takeyoshi Ohashi, Osamu Komuro
  • Patent number: 8478021
    Abstract: In order to provide a charged beam device capable of obtaining a precise image of a sample surface pattern while improving the accuracy of automatic focus/astigmatism correction, there are provided an electron gun (1), a deflection control portion (8) which allows an electron beam to scan, a focus control portion (10) and an astigmatism correction portion (3) for the electron beam, an image processing portion (11), and a switching portion (9) which switches scan conditions when obtaining pattern information of the sample (1001) surface and scan conditions when performing the automatic focus/astigmatism correction, and a scan speed and scan procedures are switched between when obtaining the pattern information and when performing the automatic focus/astigmatism correction.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: July 2, 2013
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Kaori Shirahata, Yoshinori Nakayama, Keiichiro Hitomi, Muneyuki Fukuda, Yasunari Sohda
  • Publication number: 20130026361
    Abstract: An amount of pattern position displacement between observation images acquired by irradiating from two different directions is changed depending on beam deflection for moving an image acquisition position. In a pattern evaluation method that measures astigmatic difference or focus position displacement having a small amount of dose at a high speed using parallax caused by the tilted beam, a correction value obtained in advance by measurement is reflected in an amount of pattern position displacement between observation images obtained by irradiating from at least two different directions and generated in accordance with the amount of beam deflection for moving an image acquisition position. A processing unit calculates an amount of correction of an amount of pattern position displacement depending on beam deflection of a beam deflecting unit for moving an image acquisition position on the sample at a high speed.
    Type: Application
    Filed: July 26, 2010
    Publication date: January 31, 2013
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Muneyuki Fukuda, Toru Yamanashi
  • Publication number: 20120327213
    Abstract: Disclosed is a charged particle beam microscope which can obtain information about pattern materials and stereostructure without lowering throughput of pattern dimension measurement. To achieve this, the charged particle beam microscope acquires a plurality of frame images by scanning the field of view of the sample (S304, 305), adds the images together (S307), computes the dimensions of the pattern formed on the sample (308) and at the same time acquires pattern information (314) using components of a frame image, such as a single frame image or subframe image, as a separated image (309, 310).
    Type: Application
    Filed: February 22, 2011
    Publication date: December 27, 2012
    Applicant: Hitachi high-Technologies Corporation
    Inventors: Nobuhiro Okai, Yasunari Sohda, Junichi Tanaka
  • Publication number: 20120286160
    Abstract: A charged particle instrument including a controlling and operating unit for controlling a charged particle source, deflecting means, and focus changing means and making a data for an image by an electric signal detected by a detector, and a recording unit for preserving a correction coefficient registered at each image-acquisition, in which the controlling and operating unit acquires plural images while changing a focus, and controls an optical condition such that a landing angle of a charged particle beam becomes perpendicular when an image for measurement is acquired on the basis of a position shift amount of a mark in the image and a correction coefficient registered to the recording unit.
    Type: Application
    Filed: April 20, 2012
    Publication date: November 15, 2012
    Inventors: Takeyoshi OHASHI, Yasunari Sohda, Makoto Ezumi, Muneyuki Fukuda, Noritsugu Takahashi
  • Publication number: 20120286158
    Abstract: Provided is a high-resolution scanning electron microscope with minimal aberration, and equipped with an electro-optical configuration that can form a tilted beam having wide-angle polarization and a desired angle, without interfering with an electromagnetic lens. In the scanning electron microscope, an electromagnetic deflector (201) is disposed above a magnetic lens (207), and a control electrode (202) that accelerates or decelerates electrons is provided so at to overlap (in such a manner that the height positions overlap with respect to the vertical direction) with the electromagnetic deflector (201). In wide field polarization, electrodes are accelerated, and in tilted beam formation, electrons are decelerated.
    Type: Application
    Filed: February 18, 2011
    Publication date: November 15, 2012
    Inventors: Yasunari Sohda, Takeyoshi Ohashi, Kaori Shirahata, Keiichiro Hitomi
  • Patent number: 8268209
    Abstract: In a mold in which a pattern is formed of a fine concavo-convex shape, two or more of alignment marks for determining a relative positional relation between a substrate and a mold are formed concentrically. Moreover, a damaged mark is identified from the positional information and shape of the respective marks, and an alignment between the mold and the substrate to which a resin film is applied is carried out excluding the damaged mark.
    Type: Grant
    Filed: January 17, 2007
    Date of Patent: September 18, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Ogino, Akihiro Miyauchi, Takashi Ando, Chiseki Haginoya, Susumu Komoriya, Yasunari Sohda, Souichi Katagiri, Hiroya Ohta, Yoshinori Nakayama