Patent ID: 8033895
Filing Date: 2011-10-11
Classification: B24B,H01L,Y10T

Abstract:
1. A retaining ring for chemical mechanical polishing, comprising: an annular ring having a bottom surface configured to contact a polishing pad during polishing, wherein the bottom surface has a plurality of channels, each channel of the plurality of channels defined by sidewalls, wherein corners between the sidewalls and the bottom surface have a first radius of curvature, a corner between an outer diameter of the annular ring and the bottom surface has a second radius of curvature, corners between the sidewalls and the outer diameter have a third radius of curvature that defines a first flared portion of the channel that flares out to a width adjacent the outer diameter, corners between the sidewalls and an inner diameter have a fourth radius of curvature that defines a second flared portion of the channel that flares out to a width adjacent to the inner diameter, the width adjacent the inner diameter of the retaining ring is less than the width adjacent to the outer diameter of the retaining ring, and the sidewalls are substantially parallel to one another along a length of the channel between the first flared portion and the second flared portion.