Patents by Inventor Masamitsu Itoh

Masamitsu Itoh 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: 20050019677
    Abstract: In a quadrangular photomask blank substrate with a length on each side of at least 6 inches, which has a pair of strip-like regions that extend from 2 to 10 mm inside each of a pair of opposing sides along an outer periphery of a substrate top surface, with a 2 mm edge portion excluded at each end, each strip-like region is inclined downward toward the outer periphery of the substrate, and a difference between maximum and minimum values for height from a least squares plane for the strip-like region to the strip-like region is at most 0.5 ?m. The substrate exhibits a good surface flatness at the time of wafer exposure.
    Type: Application
    Filed: July 23, 2004
    Publication date: January 27, 2005
    Inventors: Masayuki Nakatsu, Tsuneo Numanami, Masayuki Mogi, Masamitsu Itoh, Tsuneyuki Hagiwara, Naoto Kondo
  • Publication number: 20050019676
    Abstract: Provided that a pair of strip-like regions extend from 2 mm to 10 mm inside each of a pair of opposing sides along an outer periphery of a top surface of a substrate on which a mask pattern is to be formed, with a 2 mm edge portion excluded at each end in a lengthwise direction thereof, the height from a least squares plane for the strip-like regions on the substrate top surface to the strip-like regions is measured at intervals of 0.05-0.35 mm in horizontal and vertical directions, and a substrate in which the difference between the maximum and minimum values for the height among all the measurement points is ?o? ?o?? ???? 0.5 ?m is selected.
    Type: Application
    Filed: July 23, 2004
    Publication date: January 27, 2005
    Inventors: Masayuki Nakatsu, Tsuneo Numanami, Masayuki Mogi, Masamitsu Itoh, Tsuneyuki Hagiwara, Naoto Kondo
  • Publication number: 20040253524
    Abstract: A method of manufacturing an exposure mask substrate including a substrate and a light-shielding film formed on the substrate, comprising measuring a flatness of at least one substrate before formation of a light-shielding film, predicting, on the basis of a measurement result, the flatness of the substrate when the substrate is chucked on an exposure apparatus, selecting the substrate having a predetermined flatness on the basis of a prediction result, predicting, for the selected substrate, a desired flatness of the substrate after light-shielding film formation after a light-shielding film is formed on the substrate, forming a light-shielding film on the selected substrate, measuring the flatness of the substrate having the formed light-shielding film, and determining whether the substrate having the light-shielding film has the desired flatness after light-shielding film formation by comparing a measurement result with a prediction result of the flatness after light-shielding film formation.
    Type: Application
    Filed: May 26, 2004
    Publication date: December 16, 2004
    Inventor: Masamitsu Itoh
  • Publication number: 20040146789
    Abstract: There is disclosed a manufacturing method for exposure mask, which comprises acquiring a first information showing surface shape of surface of each of a plurality of mask substrates, and a second information showing the flatness of the surface of each of mask substrates before and after chucked on a mask stage of an exposure apparatus, forming a corresponding relation of each mask substrate, the first information and the second information, selecting the second information showing a desired flatness among the second information of the corresponding relation, and preparing another mask substrate having the same surface shape as the surface shape indicated by the first information in the corresponding relation with the selected second information, and forming a desired pattern on the above-mentioned another mask substrate.
    Type: Application
    Filed: January 14, 2004
    Publication date: July 29, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Masamitsu Itoh
  • Publication number: 20040106072
    Abstract: A developing method comprises determining in advance the relation of resist dissolution concentration in a developing solution and resist dissolution speed by the developing solution, estimating in advance the resist dissolution concentration where the resist dissolution speed is a desired speed or more from the relation, and developing in a state in which the resist dissolution concentration in the developing solution is the estimated dissolution concentration or less.
    Type: Application
    Filed: August 28, 2003
    Publication date: June 3, 2004
    Inventors: Masamitsu Itoh, Ikuo Yoneda, Hideaki Sakurai
  • Patent number: 6727565
    Abstract: There is disclosed a manufacturing method for exposure mask, which comprises acquiring a first information showing surface shape of surface of each of a plurality of mask substrates, and a second information showing the flatness of the surface of each of mask substrates before and after chucked on a mask stage of an exposure apparatus, forming a corresponding relation of each mask substrate, the first information and the second information, selecting the second information showing a desired flatness among the second information of the corresponding relation, and preparing another mask substrate having the same surface shape as the surface shape indicated by the first information in the corresponding relation with the selected second information, and forming a desired pattern on the above-mentioned another mask substrate.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: April 27, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masamitsu Itoh
  • Publication number: 20040072082
    Abstract: A photomask comprises a substrate, a translucent film selectively formed on the substrate, and a shading film selectively formed on the translucent film, wherein when the substrate, the translucent film and the shading film have Young's moduli (MPa) E0 E1 and E2, and film thickness (m) d0, d1 and d2 respectively, internal stresses (MPa) of the translucent film and the shading film at room temperature are s1 and s2 respectively, a covering rate by the translucent film defined by an area in which the shading film is not formed is expressed as h, and coefficients are expressed as k1=1.3×10−8, k2=−9.5×10−2, k3=6.0×10−7, and k4=−5.
    Type: Application
    Filed: July 9, 2003
    Publication date: April 15, 2004
    Inventors: Sachiyo Ito, Masamitsu Itoh, Masahiko Hasunuma
  • Publication number: 20040058279
    Abstract: This invention provides a pattern formation material for electron beam lithography, which contains an alkali-soluble resin, a photoacid generator, and dissolution inhibiting groups, and also provides a pattern formation method and exposure mask fabrication method using the material. As the dissolution inhibiting groups, this invention uses a first dissolution inhibiting group which increases the sensitivity of the pattern formation material when the material is left to stand in a vacuum after an electron beam irradiation, and a second dissolution inhibiting group which decreases the sensitivity under the same condition. In this invention, the ratio of the first dissolution inhibiting group to the second dissolution inhibiting group is so adjusted that the size of an alkali-soluble portion, which is made soluble in an alkali solution by an electron beam irradiation, is substantially held constant independently of the standing time in a vacuum.
    Type: Application
    Filed: September 22, 2003
    Publication date: March 25, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masamitsu Itoh, Takehiro Kondoh
  • Patent number: 6660455
    Abstract: This invention provides a pattern formation material for electron beam lithography, which contains an alkali-soluble resin, a photoacid generator, and dissolution inhibiting groups, and also provides a pattern formation method and exposure mask fabrication method using the material. As the dissolution inhibiting groups, this invention uses a first dissolution inhibiting group which increases the sensitivity of the pattern formation material when the material is left to stand in a vacuum after an electron beam irradiation, and a second dissolution inhibiting group which decreases the sensitivity under the same condition. In this invention, the ratio of the first dissolution inhibiting group to the second dissolution inhibiting group is so adjusted that the size of an alkali-soluble portion, which is made soluble in an alkali solution by an electron beam irradiation, is substantially held constant independently of the standing time in a vacuum.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: December 9, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masamitsu Itoh, Takehiro Kondoh
  • Patent number: 6649310
    Abstract: A method of manufacturing a photomask includes determining an average value of dimensions of a pattern in a photomask. determining an in-plane uniformity of the dimensions, determining an exposure latitude on the basis of the average value and the in-plane uniformity. The exposure latitude depends on dimensional accuracy of the pattern.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: November 18, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masamitsu Itoh, Shigeki Nojima, Shoji Mimotogi, Osamu Ikenaga
  • Publication number: 20030184721
    Abstract: A mask substrate comprises a transparent substrate including a reference mark and a light shielding film formed on the transparent substrate.
    Type: Application
    Filed: February 25, 2003
    Publication date: October 2, 2003
    Inventor: Masamitsu Itoh
  • Publication number: 20030153114
    Abstract: There is disclosed a manufacturing method for exposure mask, which comprises acquiring a first information showing surface shape of surface of each of a plurality of mask substrates, and a second information showing the flatness of the surface of each of mask substrates before and after chucked on a mask stage of an exposure apparatus, forming a corresponding relation of each mask substrate, the first information and the second information, selecting the second information showing a desired flatness among the second information of the corresponding relation, and preparing another mask substrate having the same surface shape as the surface shape indicated by the first information in the corresponding relation with the selected second information, and forming a desired pattern on the above-mentioned another mask substrate.
    Type: Application
    Filed: January 31, 2003
    Publication date: August 14, 2003
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Masamitsu Itoh
  • Patent number: 6550990
    Abstract: An apparatus for processing a substrate comprising a substrate holding mechanism for holding the substrate substantially horizontally, a chemical solution discharge/suction mechanism having a chemical solution discharge/suction portion which has a chemical solution outlet for discharging a chemical solution onto the substrate and chemical solution inlets for sucking up the chemical solution present on the substrate, and a chemical solution supply/suction system for supplying the chemical solution to the chemical solution discharge/suction mechanism simultaneously with sucking the chemical solution by the chemical solution supply/suction mechanism.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: April 22, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Sakurai, Masamitsu Itoh, Shinichi Ito
  • Patent number: 6537844
    Abstract: There is disclosed a manufacturing method for exposure mask, which comprises acquiring a first information showing surface shape of surface of each of a plurality of mask substrates, and a second information showing the flatness of the surface of each of mask substrates before and after chucked on a mask stage of an exposure apparatus, forming a corresponding relation of each mask substrate, the first information and the second information, selecting the second information showing a desired flatness among the second information of the corresponding relation, and preparing another mask substrate having the same surface shape as the surface shape indicated by the first information in the corresponding relation with the selected second information, and forming a desired pattern on the above-mentioned another mask substrate.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: March 25, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masamitsu Itoh
  • Publication number: 20020081118
    Abstract: An apparatus for processing a substrate comprising a substrate holding mechanism for holding the substrate substantially horizontally, a chemical solution discharge/suction mechanism having a chemical solution discharge/suction portion which has a chemical solution outlet for discharging a chemical solution onto the substrate and chemical solution inlets for sucking up the chemical solution present on the substrate, and a chemical solution supply/suction system for supplying the chemical solution to the chemical solution discharge/suction mechanism simultaneously with sucking the chemical solution by the chemical solution supply/suction mechanism.
    Type: Application
    Filed: December 20, 2001
    Publication date: June 27, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki Sakurai, Masamitsu Itoh, Shinichi Ito
  • Publication number: 20020025480
    Abstract: A method of manufacturing a photomask comprises determining an average value and an in-plane uniformity in a dimension of a pattern of the photomask, determining an exposure latitude as the photomask is employed on the basis of the average value and the in-plane uniformity in the dimension of the pattern, and judging if the photomask is defective or non-defective on the basis of whether or not the exposure latitude is determined satisfy a prescribed exposure latitude.
    Type: Application
    Filed: August 29, 2001
    Publication date: February 28, 2002
    Inventors: Masamitsu Itoh, Shigeki Nojima, Shoji Mimotogi, Osamu Ikenaga
  • Patent number: 6316163
    Abstract: A method for forming patterns, in which pattern transfer to the same photosensitive material on a first layer is carried out using both light exposure and charged particle beam exposure, comprises the steps of performing a predetermined geometric operation between data associated with a pattern to be transferred to the first layer and data associated with a pattern to be transferred to a second layer different from the first layer, separating the pattern data associated with the pattern to be transferred to the first layer into first exposure pattern data for charged particle beam exposure and second exposure pattern data for light exposure, and performing pattern transfer on to the first layer based on the result of the separation.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: November 13, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shunko Magoshi, Masamitsu Itoh, Shinji Sato, Soichi Inoue, Kazuyoshi Sugihara, Katsuya Okumura
  • Publication number: 20010026895
    Abstract: This invention provides a pattern formation material for electron beam lithography, which contains an alkali-soluble resin, a photoacid generator, and dissolution inhibiting groups, and also provides a pattern formation method and exposure mask fabrication method using the material. As the dissolution inhibiting groups, this invention uses a first dissolution inhibiting group which increases the sensitivity of the pattern formation material when the material is left to stand in a vacuum after an electron beam irradiation, and a second dissolution inhibiting group which decreases the sensitivity under the same condition. In this invention, the ratio of the first dissolution inhibiting group to the second dissolution inhibiting group is so adjusted that the size of an alkali-soluble portion, which is made soluble in an alkali solution by an electron beam irradiation, is substantially held constant independently of the standing time in a vacuum.
    Type: Application
    Filed: March 21, 2001
    Publication date: October 4, 2001
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Masamitsu Itoh, Takehiro Kondoh
  • Patent number: 6204511
    Abstract: In the electron beam drawing method, the optimal irradiation amount of an electron beam in accordance with a drawing area ratio at each of drawing positions, is obtained prior to drawing a desired pattern by irradiating an electron beam on a sample. The optimal irradiation amount obtained is separated in a plurality of gradations as a correction amount for a reference irradiation amount of the electron beam. This separation is made finer as the drawing area ratio is higher. The representative correction amount data is determined for each of the plurality of gradations. The representative correction amount data determined is stored for each of the plurality of gradations, and a pattern is drawn on a sample with the optical irradiation amount corresponding to read data of the representative correction amount stored.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: March 20, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masamitsu Itoh, Shunko Magoshi, Shinji Sato
  • Patent number: 6172364
    Abstract: A reflection prevention board of a charged particle beam irradiation apparatus of the present invention comprises a laminate sheet having a plurality of thin films and a plurality of microholes through the laminate sheet. According to the present invention the reflection prevention board can be manufactured at a lower cost, the reason being that it is easier to form microholes in the thin films and then laminate these thin films in an aligned relation than to drill holes through a thicker sheet. By doing so it is possible to achieve a better yield. Further, much deeper microholes, which might not otherwise be achieved on a thick sheet, can be formed by using more thin films and a reflection prevention effect can be improved by doing so.
    Type: Grant
    Filed: July 20, 1998
    Date of Patent: January 9, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Munehiro Ogasawara, Jun Takamatsu, Naoharu Shimomura, Shusuke Yoshitake, Takayuki Abe, Masamitsu Itoh