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).
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Patent number: 10730161Abstract: 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: GrantFiled: August 31, 2016Date of Patent: August 4, 2020Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Taichi Yasuda, Masanao Sasaki, Tatsuo Enomoto, Takuya Sasaki, Kazumasa Asai
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Publication number: 20180264618Abstract: 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: ApplicationFiled: August 31, 2016Publication date: September 20, 2018Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Taichi YASUDA, Masanao SASAKI, Tatsuo ENOMOTO, Takuya SASAKI, Kazumasa ASAI
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Patent number: 9987721Abstract: 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: GrantFiled: August 8, 2013Date of Patent: June 5, 2018Inventors: Masanao Sasaki, Kazuaki Aoki, Taichi Yasuda, Taketoshi Sato, Takehiro Yuasa, Kazumasa Asai, Daisuke Furukawa
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Patent number: 9862072Abstract: 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: GrantFiled: October 21, 2013Date of Patent: January 9, 2018Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Kazumasa Asai
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Patent number: 9108289Abstract: 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: GrantFiled: July 30, 2014Date of Patent: August 18, 2015Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Daisuke Furukawa, Kazumasa Asai, Takahiro Kida, Tadao Tanaka
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Publication number: 20150217425Abstract: 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: ApplicationFiled: August 8, 2013Publication date: August 6, 2015Applicant: Shin-Etsu Handotai Co., Ltd.Inventors: Masanao Sasaki, Kazuaki Aoki, Taichi Yasuda, Taketoshi Sato, Takehiro Yuasa, Kazumasa Asai, Daisuke Furukawa
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Publication number: 20150209931Abstract: 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: ApplicationFiled: October 21, 2013Publication date: July 30, 2015Inventor: Kazumasa Asai
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Publication number: 20150031271Abstract: 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: ApplicationFiled: July 30, 2014Publication date: January 29, 2015Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Daisuke FURUKAWA, Kazumasa ASAI, Takahiro KIDA, Tadao TANAKA
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Patent number: 8834230Abstract: 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: GrantFiled: June 30, 2009Date of Patent: September 16, 2014Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Daisuke Furukawa, Kazumasa Asai, Takahiro Kida, Tadao Tanaka
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Publication number: 20110130073Abstract: 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: ApplicationFiled: June 30, 2009Publication date: June 2, 2011Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Daisuke Furukawa, Kazumasa Asai, Takahiro Kida, Tadao Tanaka