Retaining ring for cmp

Abstract

A retaining ring includes: a generally annular body having an inner surface to constrain a substrate and a bottom surface, the bottom surface having multiple channels extending from an outer surface to the inner surface. Each channel of the multiple channels includes an inner channel and outer channel connected by a reservoir channel, the reservoir channel having an annular shape within the bottom surface. The outer channel has two opposing sidewalls and both opposing sidewalls of the outer channel have an inflection point.

Dependencies are inferred from the claim text.