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:
Aug. 31, 1999
Filed:
Oct. 28, 1997
Daniel Chiu, Hsinchu Hsien, TW;
C C Yang, Hsinchu, TW;
Peng-Yih Peng, Hsinchu Hsien, TW;
J Y Wu, Hsinchu, TW;
J S Lai, Kaohsiung Hsien, TW;
Abstract
A retainer ring is provided for used on the polishing head of a CMP machine, which can allow the slurry being applied to the CMP process to be uniformly distributed over the surface of the wafer. The retainer ring is designed for use on a CMP machine of the type having a polishing table, a polishing pad, a polishing head for holding a semiconductor wafer retained in fixed position, and means for applying a mass of slurry to the wafer. The polishing head is of the type including an air-pressure means which can apply air pressure to a wafer loader used to hold the wafer in position. The retainer ring is formed with a plurality of straight grooves spaced at substantially equal intervals, each being radially inclined in such a manner so as to form an acute angle of attack against the slurry on the outside of said retainer ring when said retainer ring spins. Further, the retainer ring can be additionally formed with at least one circular groove intercrossing all of said straight grooves. The straight grooves can cause the slurry to be drawn into the inside of the retainer ring from all radial directions, thus allowing the slurry to be spread uniformly over the wafer.