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. 16, 1999
Filed:
May. 17, 1996
Ritsuo Kikuta, Ichikawa, JP;
Fujio Aoyama, Zama, JP;
Koji Kato, Fujisawa, JP;
Tamami Takahashi, Yamato, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A polishing cloth mounted on a turntable of a polishing apparatus and a polishing apparatus having such a polishing cloth for polishing a workpiece such as a semiconductor wafer to a flat mirror finish. The polishing cloth comprises a first elastic region contacting the surface of the workpiece and having a certain elastic modulus, and a second elastic region contacting the surface of the workpiece and having an elastic modulus different from the first elastic region. The second elastic region is surrounded by the first elastic region and has a smaller dimension in a radial direction of the turntable than a diameter of the workpiece when the second elastic region is held in contact with the workpiece. The position of the second elastic region is determined on the basis of an area in which the second elastic region acts on the workpiece.