Patents by Inventor Yasutaka Tochihara

Yasutaka Tochihara 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).

  • Method of determining a flatness of an electronic device substrate, method of producing the substrate, method of producing a mask blank, method of producing a transfer mask, polishing method, electronic device substrate, mask blank, transfer mask, and polishing apparatus
    Patent number: 7455785
    Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 ?m and not greater than 0.25 ?m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: November 25, 2008
    Assignee: Hoya Corporation
    Inventors: Kesahiro Koike, Masato Ohtsuka, Yasutaka Tochihara
  • METHOD OF DETERMINING A FLATNESS OF AN ELECTRONIC DEVICE SUBSTRATE, METHOD OF PRODUCING THE SUBSTRATE, METHOD OF PRODUCING A MASK BLANK, METHOD OF PRODUCING A TRANSFER MASK, POLISHING METHOD, ELECTRONIC DEVICE SUBSTRATE, MASK BLANK, TRANSFER MASK, AND POLISHING APPARATUS
    Patent number: 6951502
    Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 ?m and not greater than 0.25 ?m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: October 4, 2005
    Assignee: Hoya Corporation
    Inventors: Kesahiro Koike, Masato Ohtsuka, Yasutaka Tochihara
  • Method of determining a flatness of an electronic device substrate, method of producing the substrate, method of producing a mask blank, method of producing a transfer mask, polishing method, electronic device substrate, mask blank, transfer mask, and polishing apparatus
    Publication number: 20050186691
    Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 ?m and not greater than 0.25 ?m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.
    Type: Application
    Filed: April 26, 2005
    Publication date: August 25, 2005
    Inventors: Kesahiro Koike, Masato Ohtsuka, Yasutaka Tochihara
  • Method of determining a flatness of an electronic device substrate, method of producing the substrate, method of producing a mask blank, method of producing a transfer mask, polishing method, electronic device substrate, mask blank, transfer mask, and polishing apparatus
    Publication number: 20030186624
    Abstract: A flatness of a substrate is determined to achieve a desired flatness of a mask blank by predicting the variation in flatness resulting from a film stress of a thin film formed on the substrate. The flatness is adjusted by measuring the flatness of the substrate as a measured flatness, selecting a load type with reference to the measured flatness, and polishing the substrate under pressure distribution specified by the load type. A principal surface of the substrate has a flatness greater than 0 &mgr;m and not greater than 0.25 &mgr;m. A polishing apparatus includes a rotatable surface table, a polishing pad formed thereon, abrasive supplying means for supplying an abrasive to the polishing pad, substrate holding means, and substrate pressing means for pressing the substrate. The substrate pressing means has a plurality of pressing members for individually and desirably pressing a plurality of divided regions of the substrate surface.
    Type: Application
    Filed: March 31, 2003
    Publication date: October 2, 2003
    Applicant: HOYA CORPORATION
    Inventors: Kesahiro Koike, Masato Ohtsuka, Yasutaka Tochihara