Patents by Inventor Kazumasa Asai

Kazumasa Asai 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: 10730161
    Abstract: A method for conditioning a polishing pad, which is configured to polish a wafer and attached to a rotatable discoid turntable, by using a conditioning head, the method being characterized by: moving the conditioning head in a radial direction of the turntable to perform the conditioning while rotating the polishing pad attached to the turntable by rotation of the turntable; and controlling a rotational speed of the turntable and a moving speed of the conditioning head in the radial direction of the turntable in correspondence with a distance of the conditioning head from a center of the turntable. Consequently, the method for conditioning a polishing pad which enables appropriately conditioning an entire polishing surface of the polishing pad can be provided.
    Type: Grant
    Filed: August 31, 2016
    Date of Patent: August 4, 2020
    Assignee: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Taichi Yasuda, Masanao Sasaki, Tatsuo Enomoto, Takuya Sasaki, Kazumasa Asai
  • Publication number: 20180264618
    Abstract: A method for conditioning a polishing pad, which is configured to polish a wafer and attached to a rotatable discoid turntable, by using a conditioning head, the method being characterized by: moving the conditioning head in a radial direction of the turntable to perform the conditioning while rotating the polishing pad attached to the turntable by rotation of the turntable; and controlling a rotational speed of the turntable and a moving speed of the conditioning head in the radial direction of the turntable in correspondence with a distance of the conditioning head from a center of the turntable. Consequently, the method for conditioning a polishing pad which enables appropriately conditioning an entire polishing surface of the polishing pad can be provided.
    Type: Application
    Filed: August 31, 2016
    Publication date: September 20, 2018
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Taichi YASUDA, Masanao SASAKI, Tatsuo ENOMOTO, Takuya SASAKI, Kazumasa ASAI
  • Patent number: 9987721
    Abstract: A double-side polishing method of polishing both surfaces of a wafer by holding the wafer with a carrier including a holding hole configured to hold the wafer and a ring-shaped resin insert disposed along an internal circumference of the holding hole, the resin insert having an inner circumferential surface configured to contact a peripheral portion of the wafer, interposing the carrier between upper and lower turn tables to which polishing pads are attached, polishing both the surfaces of the wafer while maintaining planarity of the inner circumferential surface at or below 100 ?m and verticalness of the inner circumferential surface at or below 5°. The method can inhibit the degradation of the flatness of the polished wafer, such as particularly an outer circumferential sag, due to variation in shape of the inner circumferential surface of the resin insert of a carrier.
    Type: Grant
    Filed: August 8, 2013
    Date of Patent: June 5, 2018
    Inventors: Masanao Sasaki, Kazuaki Aoki, Taichi Yasuda, Taketoshi Sato, Takehiro Yuasa, Kazumasa Asai, Daisuke Furukawa
  • Patent number: 9862072
    Abstract: The invention provides a double-side polishing method including first polishing at a high polishing rate, second polishing at a low polishing rate, dividing a straight line extending between the outermost circumferences of the wafer through the center into prescribed sections, and optically measuring a cross-sectional shape of the sections; applying a weight predetermined for each section to the cross-sectional shape to quantify flatness of each section; and determining polishing conditions of the first and second polishing in subsequent polishing on a basis of the quantified flatness, wherein a beam diameter of a measurement apparatus used to measure the cross-sectional shape of outermost sections is smaller than that used to measure the cross-sectional shape of the other section. The method can measure the shape of the wafer up to its outermost circumference with high precision without reducing productivity, and improve the flatness of the entire wafer including its outermost circumference.
    Type: Grant
    Filed: October 21, 2013
    Date of Patent: January 9, 2018
    Assignee: SHIN-ETSU HANDOTAI CO., LTD.
    Inventor: Kazumasa Asai
  • Patent number: 9108289
    Abstract: A wafer polishing apparatus configured to polish simultaneously both surfaces of a wafer by pressing and rubbing the wafer, while holding the wafer with: a lower turn table having a flat polishing-upper-surface rotationally driven; an upper turn table having a flat polishing-lower-surface rotationally driven, the upper turn table being arranged with facing to the lower turn table; and a carrier having a wafer-holding hole for holding the wafer, wherein the polishing is performed while measuring a thickness of the wafer through a plurality of openings provided between a rotation center and an edge of the upper turn table or the lower turn table, and switching a polishing slurry with a polishing slurry having a different polishing rate during the polishing of the wafer. As a result, the wafer polishing apparatus can manufacture a wafer having a high flatness and a high smoothness at high productivity and high yield.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: August 18, 2015
    Assignee: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Daisuke Furukawa, Kazumasa Asai, Takahiro Kida, Tadao Tanaka
  • Publication number: 20150217425
    Abstract: A double-side polishing method of polishing both surfaces of a wafer by holding the wafer with a carrier including a holding hole configured to hold the wafer and a ring-shaped resin insert disposed along an internal circumference of the holding hole, the resin insert having an inner circumferential surface configured to contact a peripheral portion of the wafer, interposing the carrier between upper and lower turn tables to which polishing pads are attached, polishing both the surfaces of the wafer while maintaining planarity of the inner circumferential surface at or below 100 ?m and verticalness of the inner circumferential surface at or below 5°. The method can inhibit the degradation of the flatness of the polished wafer, such as particularly an outer circumferential sag, due to variation in shape of the inner circumferential surface of the resin insert of a carrier.
    Type: Application
    Filed: August 8, 2013
    Publication date: August 6, 2015
    Applicant: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masanao Sasaki, Kazuaki Aoki, Taichi Yasuda, Taketoshi Sato, Takehiro Yuasa, Kazumasa Asai, Daisuke Furukawa
  • Publication number: 20150209931
    Abstract: The invention provides a double-side polishing method including first polishing at a high polishing rate, second polishing at a low polishing rate, dividing a straight line extending between the outermost circumferences of the wafer through the center into prescribed sections, and optically measuring a cross-sectional shape of the sections; applying a weight predetermined for each section to the cross-sectional shape to quantify flatness of each section; and determining polishing conditions of the first and second polishing in subsequent polishing on a basis of the quantified flatness, wherein a beam diameter of a measurement apparatus used to measure the cross-sectional shape of outermost sections is smaller than that used to measure the cross-sectional shape of the other section. The method can measure the shape of the wafer up to its outermost circumference with high precision without reducing productivity, and improve the flatness of the entire wafer including its outermost circumference.
    Type: Application
    Filed: October 21, 2013
    Publication date: July 30, 2015
    Inventor: Kazumasa Asai
  • Publication number: 20150031271
    Abstract: A wafer polishing apparatus configured to polish simultaneously both surfaces of a wafer by pressing and rubbing the wafer, while holding the wafer with: a lower turn table having a flat polishing-upper-surface rotationally driven; an upper turn table having a flat polishing-lower-surface rotationally driven, the upper turn table being arranged with facing to the lower turn table; and a carrier having a wafer-holding bole for holding the wafer, wherein the polishing is performed while measuring a thickness of the wafer through a plurality of openings provided between a rotation center and an edge of the upper turn table or the lower turn table, and switching a polishing slurry with a polishing slurry having a different polishing rate during the polishing of the wafer. As a result, the wafer polishing apparatus can manufacture a wafer having a high flatness and a high smoothness at high productivity and high yield.
    Type: Application
    Filed: July 30, 2014
    Publication date: January 29, 2015
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Daisuke FURUKAWA, Kazumasa ASAI, Takahiro KIDA, Tadao TANAKA
  • Patent number: 8834230
    Abstract: The present invention is a wafer polishing method including simultaneously polishing both surfaces of a wafer by pressing and rubbing the wafer, while holding the wafer with: a lower turn table having a flat polishing-upper-surface rotationally driven; an upper turn table having a flat polishing-lower-surface rotationally driven, the upper turn table being arranged with facing to the lower turn table; and a carrier having a wafer-holding hole for holding the wafer, wherein the polishing is performed while measuring a thickness of the wafer through a plurality of openings provided between a rotation center and an edge of the upper turn table or the lower turn table, and switching a polishing slurry with a polishing slurry having a different polishing rate during the polishing of the wafer. As a result, there is provided a wafer polishing method that can manufacture a wafer having a high flatness and a high smoothness at high productivity and high yield.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: September 16, 2014
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Daisuke Furukawa, Kazumasa Asai, Takahiro Kida, Tadao Tanaka
  • Publication number: 20110130073
    Abstract: The present invention is a wafer polishing method including simultaneously polishing both surfaces of a wafer by pressing and rubbing the wafer, while holding the wafer with: a lower turn table having a flat polishing-upper-surface rotationally driven; an upper turn table having a flat polishing-lower-surface rotationally driven, the upper turn table being arranged with facing to the lower turn table; and a carrier having a wafer-holding hole for holding the wafer, wherein the polishing is performed while measuring a thickness of the wafer through a plurality of openings provided between a rotation center and an edge of the upper turn table or the lower turn table, and switching a polishing slurry with a polishing slurry having a different polishing rate during the polishing of the wafer. As a result, there is provided a wafer polishing method that can manufacture a wafer having a high flatness and a high smoothness at high productivity and high yield.
    Type: Application
    Filed: June 30, 2009
    Publication date: June 2, 2011
    Applicant: SHIN-ETSU HANDOTAI CO., LTD.
    Inventors: Daisuke Furukawa, Kazumasa Asai, Takahiro Kida, Tadao Tanaka