The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 1998
Filed:
Nov. 04, 1996
Tamami Takahashi, Yamato, JP;
Fumihiko Sakata, Yokohama, JP;
Norio Kimura, Fujisawa, JP;
Masako Kodera, Yokohama, JP;
Atsushi Shigeta, Fujisawa, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A method and apparatus for determining a planar end point on a workpiece such as a semiconductor wafer in a polishing process for polishing the workpiece to a flat mirror finish. The workpiece having an uneven surface is held by a top ring and pressed against a polishing platen. The workpiece is moved relative to the polishing platen to polish the workpiece, and a change in a frictional force between the workpiece and the polishing platen is detected. A reference time when the workpiece having an uneven surface is polished to a flat surface is determined based on the change of the frictional force between the workpiece and the polishing platen. The time when a certain period of polishing time from the reference time elapses is determined as an endpoint on the workpiece.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile