Patents by Inventor Shinrou Ohta
Shinrou Ohta 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: 9068814Abstract: A method monitors a change in thickness of a conductive film brought into sliding contact with a polishing surface of a polishing pad using an eddy current sensor. The output signal of the eddy current sensor includes two signals corresponding to a resistance component and an inductive reactance component of an impedance of an electric circuit including a coil of the eddy current sensor.Type: GrantFiled: October 10, 2008Date of Patent: June 30, 2015Assignee: EBARA CORPORATIONInventors: Taro Takahashi, Yoichi Kobayashi, Shinrou Ohta, Akihiko Ogawa
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Patent number: 8777694Abstract: Method and apparatus for detecting an accurate polishing endpoint of a substrate based on a change in polishing rate are provided. The method includes: applying a light to the surface of the substrate and receiving a reflected light from the substrate; obtaining a plurality of spectral profiles at predetermined time intervals, each spectral profile indicating reflection intensity at each wavelength of the reflected light; selecting at least one pair of spectral profiles, including a latest spectral profile, from the plurality of spectral profiles obtained; calculating a difference in the reflection intensity at a predetermined wavelength between the spectral profiles selected; determining an amount of change in the reflection intensity from the difference; and determining a polishing endpoint based on the amount of change.Type: GrantFiled: September 25, 2013Date of Patent: July 15, 2014Assignees: Ebara Corporation, Kabushiki Kaisha ToshibaInventors: Shinrou Ohta, Atsushi Shigeta
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Publication number: 20140030826Abstract: A method of polishing a wafer having a Ru film and a Ta film or TaN film beneath the Ru film is provided. This polishing method includes: polishing the Ru film by bringing the wafer into sliding contact with a polishing pad; measuring a thickness of the Ru film by a film thickness sensor while polishing the Ru film; calculating a derivative value of an output value of the film thickness sensor; detecting a predetermined point of change in the derivative value; and determining a removal point of the Ru film from a point of time when the point of change is detected.Type: ApplicationFiled: July 24, 2012Publication date: January 30, 2014Inventors: Shinrou Ohta, Toshikazu Nomura, Takeshi Iizumi
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Publication number: 20140024294Abstract: Method and apparatus for detecting an accurate polishing endpoint of a substrate based on a change in polishing rate are provided. The method includes: applying a light to the surface of the substrate and receiving a reflected light from the substrate; obtaining a plurality of spectral profiles at predetermined time intervals, each spectral profile indicating reflection intensity at each wavelength of the reflected light; selecting at least one pair of spectral profiles, including a latest spectral profile, from the plurality of spectral profiles obtained; calculating a difference in the reflection intensity at a predetermined wavelength between the spectral profiles selected; determining an amount of change in the reflection intensity from the difference; and determining a polishing endpoint based on the amount of change.Type: ApplicationFiled: September 25, 2013Publication date: January 23, 2014Applicants: KABUSHIKI KAISHA TOSHIBA, EBARA CORPORATIONInventors: Shinrou OHTA, Atsushi SHIGETA
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Patent number: 8585460Abstract: A method of polishing end point detection includes polishing a surface of a substrate; applying light to the surface of the substrate and receiving reflected light from the substrate during the polishing of the substrate; measuring reflection intensities of the reflected light at respective wavelengths; creating a spectral profile indicating a relationship between reflection intensity and wavelength from the reflection intensities measured; extracting at least one extremal point indicating extremum of the reflection intensities from the spectral profile; during polishing of the substrate, repeating the creating of the spectral profile and the extracting of the at least one extremal point to obtain plural spectral profiles and plural extremal points; and detecting the polishing end point based on an amount of relative change in the extremal point between the plural spectral profiles.Type: GrantFiled: December 12, 2012Date of Patent: November 19, 2013Assignee: Ebara CorporationInventors: Yoichi Kobayashi, Shinrou Ohta, Toshifumi Kimba, Masaki Kinoshita
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Patent number: 8568199Abstract: Method and apparatus for detecting an accurate polishing endpoint of a substrate based on a change in polishing rate are provided. The method includes: applying a light to the surface of the substrate and receiving a reflected light from the substrate; obtaining a plurality of spectral profiles at predetermined time intervals, each spectral profile indicating reflection intensity at each wavelength of the reflected light; selecting at least one pair of spectral profiles, including a latest spectral profile, from the plurality of spectral profiles obtained; calculating a difference in the reflection intensity at a predetermined wavelength between the spectral profiles selected; determining an amount of change in the reflection intensity from the difference; and determining a polishing endpoint based on the amount of change.Type: GrantFiled: October 5, 2010Date of Patent: October 29, 2013Assignees: Ebara Corporation, Kabushiki Kaisha ToshibaInventors: Shinrou Ohta, Atsushi Shigeta
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Patent number: 8388408Abstract: A method of producing a diagram for use in selecting wavelengths of light in optical polishing end point detection is provided. The method includes polishing a surface of a substrate having a film by a polishing pad; applying light to the surface of the substrate and receiving reflected light from the substrate during the polishing of the substrate; calculating relative reflectances of the reflected light at respective wavelengths; determining wavelengths of the reflected light which indicate a local maximum point and a local minimum point of the relative reflectances which vary with a polishing time; identifying a point of time when the wavelengths, indicating the local maximum point and the local minimum point, are determined; and plotting coordinates, specified by the wavelengths and the point of time corresponding to the wavelengths, onto a coordinate system having coordinate axes indicating wavelength of the light and polishing time.Type: GrantFiled: August 14, 2009Date of Patent: March 5, 2013Assignee: Ebara CorporationInventors: Yoichi Kobayashi, Noburu Shimizu, Shinrou Ohta
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Patent number: 8157616Abstract: A method for detecting an end point of a polishing operation (e.g., a polishing stop point or a changing point of polishing conditions) of a film of a substrate is described. The method includes applying light to a surface of a substrate during polishing of the substrate; receiving reflected light from the surface of the substrate, monitoring a first characteristic value and a second characteristic value calculated from reflection intensities at different wavelengths; detecting a point when an extremal point of the first characteristic value and an extremal point of the second characteristic value appear within a predetermined time difference; after detecting the point, detecting a predetermined extremal point of the first characteristic value or the second characteristic value; and determining a polishing end point based on a point when the predetermined extremal point is detected.Type: GrantFiled: June 2, 2009Date of Patent: April 17, 2012Assignee: Ebara CorporationInventors: Noburu Shimizu, Shinrou Ohta
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Patent number: 8078419Abstract: A method monitors a change in film thickness during polishing using an eddy current sensor. This method includes acquiring an output signal of the eddy current sensor as a correction signal value during water-polishing of a substrate, during dressing of the polishing pad, or during replacement of the polishing pad, calculating a correcting amount from a difference between the correction signal value and a predetermined correction reference value, calculating an actual measurement signal value by subtracting the correction amount from the output signal of the eddy current sensor when polishing a substrate having a conductive film, and monitoring a change in thickness of the conductive film during polishing by monitoring a change in the actual measurement signal value.Type: GrantFiled: October 9, 2008Date of Patent: December 13, 2011Assignee: Ebara CorporationInventors: Yoichi Kobayashi, Taro Takahashi, Yasumasa Hiroo, Akihiko Ogawa, Shinrou Ohta
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Patent number: 7960188Abstract: A method for polishing a substrate having a metal film thereon is described. The substrate has metal interconnects formed from part of the metal film. The polishing method includes performing a first polishing process of removing the metal film, after the first polishing process, performing a second polishing process of removing the barrier film, after the second polishing process, performing a third polishing process of polishing the insulating film. During the second polishing process and the third polishing process, a polishing state of the substrate is monitored with an eddy current sensor, and the third polishing process is terminated when an output signal of the eddy current sensor reaches a predetermined threshold.Type: GrantFiled: May 13, 2009Date of Patent: June 14, 2011Assignee: Ebara CorporationInventors: Shinrou Ohta, Mitsuo Tada, Noburu Shimizu, Yoichi Kobayashi, Taro Takahashi, Eisaku Hayashi, Hiromitsu Watanabe, Tatsuya Kohama, Itsuki Kobata
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Publication number: 20110081829Abstract: Method and apparatus for detecting an accurate polishing endpoint of a substrate based on a change in polishing rate are provided. The method includes: applying a light to the surface of the substrate and receiving a reflected light from the substrate; obtaining a plurality of spectral profiles at predetermined time intervals, each spectral profile indicating reflection intensity at each wavelength of the reflected light; selecting at least one pair of spectral profiles, including a latest spectral profile, from the plurality of spectral profiles obtained; calculating a difference in the reflection intensity at a predetermined wavelength between the spectral profiles selected; determining an amount of change in the reflection intensity from the difference; and determining a polishing endpoint based on the amount of change.Type: ApplicationFiled: October 5, 2010Publication date: April 7, 2011Inventors: Shinrou OHTA, Atsushi Shigeta
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Patent number: 7780503Abstract: A polishing apparatus makes it possible to polish and remove an extra conductive film while preventing the occurrence of erosion and without lowering of the throughput. The polishing apparatus includes: a polishing table having a polishing surface; a top ring for holding a workpiece having a surface conductive film, and pressing the conductive film against the polishing surface to polish the conductive film; an optical sensor for monitoring the polishing state of the conductive film by emitting light toward the conductive film of the workpiece held by the top ring, receiving reflected light from the conductive film, and measuring a change in the reflectance of the reflected light; and a control section for controlling a pressure at which the workpiece is pressed on the polishing surface.Type: GrantFiled: November 19, 2008Date of Patent: August 24, 2010Assignee: Ebara CorporationInventors: Shinrou Ohta, Noburu Shimizu, Yoichi Kobayashi
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Publication number: 20100093260Abstract: A method of producing a diagram for use in selecting wavelengths of light in optical polishing end point detection is provided. The method includes polishing a surface of a substrate having a film by a polishing pad; applying light to the surface of the substrate and receiving reflected light from the substrate during the polishing of the substrate; calculating relative reflectances of the reflected light at respective wavelengths; determining wavelengths of the reflected light which indicate a local maximum point and a local minimum point of the relative reflectances which vary with a polishing time; identifying a point of time when the wavelengths, indicating the local maximum point and the local minimum point, are determined; and plotting coordinates, specified by the wavelengths and the point of time corresponding to the wavelengths, onto a coordinate system having coordinate axes indicating wavelength of the light and polishing time.Type: ApplicationFiled: August 14, 2009Publication date: April 15, 2010Inventors: Yoichi Kobayashi, Noburu Shimizu, Shinrou Ohta, Toshifumi Kimba, Masaki Kinoshita
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Publication number: 20090298387Abstract: A method for detecting an end point of a polishing operation (e.g., a polishing stop point or a changing point of polishing conditions) of a film of a substrate is described. The method includes applying light to a surface of a substrate during polishing of the substrate; receiving reflected light from the surface of the substrate, monitoring a first characteristic value and a second characteristic value calculated from reflection intensities at different wavelengths; detecting a point when an extremal point of the first characteristic value and an extremal point of the second characteristic value appear within a predetermined time difference; after detecting the point, detecting a predetermined extremal point of the first characteristic value or the second characteristic value; and determining a polishing end point based on a point when the predetermined extremal point is detected.Type: ApplicationFiled: June 2, 2009Publication date: December 3, 2009Inventors: Noburu SHIMIZU, Shinrou Ohta
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Publication number: 20090286332Abstract: A method for polishing a substrate having a metal film thereon is described. The substrate has metal interconnects formed from part of the metal film. The polishing method includes performing a first polishing process of removing the metal film, after the first polishing process, performing a second polishing process of removing the barrier film, after the second polishing process, performing a third polishing process of polishing the insulating film, during the second polishing process and the third polishing process, monitoring a polishing state of the substrate with an eddy current sensor, and terminating the third polishing process when an output signal of the eddy current sensor reaches a predetermined threshold.Type: ApplicationFiled: May 13, 2009Publication date: November 19, 2009Inventors: Shinrou OHTA, Mitsuo Tada, Noburu Shimizu, Yoichi Kobayashi, Taro Takahashi, Eisaku Hayashi, Hiromitsu Watanabe, Tatsuya Kohama, Itsuki Kobata
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Patent number: 7547242Abstract: A substrate polishing apparatus polishes a substrate to a flat mirror finish. The substrate polishing apparatus has a polishing table against which a substrate is pressed, a light-emitting and light-receiving device to emit measurement light from the polishing table to the substrate and to receive reflected light from the substrate for measuring a film on the substrate, a fluid supply passage for supplying a measurement fluid, through which the measurement light and the reflected light pass, to a fluid chamber provided at a light-emitting and light-receiving position of the polishing table, and a fluid supply control device for controlling supply of the measurement fluid to the fluid chamber.Type: GrantFiled: May 19, 2004Date of Patent: June 16, 2009Assignees: Ebara Corporation, Shimadzu CorporationInventors: Kazuto Hirokawa, Yoichi Kobayashi, Shunsuke Nakai, Shinrou Ohta, Yasuo Tsukuda
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Publication number: 20090130956Abstract: A polishing apparatus makes it possible to polish and remove an extra conductive film while preventing the occurrence of erosion and without lowering of the throughput. The polishing apparatus includes: a polishing table having a polishing surface; a top ring for holding a workpiece having a surface conductive film, and pressing the conductive film against the polishing surface to polish the conductive film; an optical sensor for monitoring the polishing state of the conductive film by emitting light toward the conductive film of the workpiece held by the top ring, receiving reflected light from the conductive film, and measuring a change in the reflectance of the reflected light; and a control section for controlling a pressure at which the workpiece is pressed on the polishing surface.Type: ApplicationFiled: November 19, 2008Publication date: May 21, 2009Inventors: Shinrou Ohta, Noburu Shimizu, Yoichi Kobayashi
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Publication number: 20090104847Abstract: The present invention provides a method of monitoring a change in film thickness during polishing using an eddy current sensor. This method includes acquiring an output signal of the eddy current sensor as a correction signal value during water-polishing of a substrate, during dressing of the polishing pad, or during replacement of the polishing pad, calculating a correcting amount from a difference between the correction signal value and a predetermined correction reference value, calculating an actual measurement signal value by subtracting the correction amount from the output signal of the eddy current sensor when polishing a substrate having a conductive film, and monitoring a change in thickness of the conductive film during polishing by monitoring a change in the actual measurement signal value.Type: ApplicationFiled: October 9, 2008Publication date: April 23, 2009Inventors: Yoichi Kobayashi, Taro Takahashi, Yasumasa Hiroo, Akihiko Ogawa, Shinrou Ohta
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Publication number: 20090096446Abstract: The present invention provides a method for monitoring a change in thickness of a conductive film brought into sliding contact with a polishing surface of a polishing pad using an eddy current sensor. The output signal of the eddy current sensor comprises two signals corresponding to a resistance component and an inductive reactance component of an impedance of an electric circuit including a coil of the eddy current sensor.Type: ApplicationFiled: October 10, 2008Publication date: April 16, 2009Inventors: Taro Takahashi, Yoichi Kobayashi, Shinrou Ohta, Akihiko Ogawa
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Patent number: 7507144Abstract: A substrate polishing apparatus is used to polish a surface of a substrate such as a semiconductor wafer to a flat mirror finish. The substrate polishing apparatus has a polishing table and a polishing pad mounted on the polishing table for polishing a semiconductor substrate. The polishing pad has a through hole formed therein. The substrate polishing apparatus also has a light emission and reception device for emitting measurement light through the through hole formed in the polishing pad to the semiconductor substrate and receiving reflected light from the semiconductor substrate so as to measure a film on the semiconductor substrate. The light emission and reception device is disposed in the polishing table. The substrate polishing apparatus includes a supply passage for supplying a fluid to a path of the measurement light. The supply passage has an outlet portion detachably mounted on the polishing table.Type: GrantFiled: March 28, 2007Date of Patent: March 24, 2009Assignee: Ebara CorporationInventors: Kazuto Hirokawa, Shunsuke Nakai, Shinrou Ohta, Yutaka Wada, Yoichi Kobayashi