Retaining ring with shaped surface

A retaining ring for use in chemical mechanical polishing, comprising:

• a substantially annular body having a top surface, an inner diameter surface adjacent to the top surface, an outer diameter surface adjacent to the top surface, and a bottom surface, wherein the bottom surface consists of exactly one frustoconical surface extending between the inner diameter surface and the outer diameter surface, the exactly one frustoconical surface slopes downwardly from the inner diameter surface to the outer diameter surface, and a difference in height across the bottom surface is between 0.002 mm and 0.02 mm.

A retaining ring comprising:

• an annular body having a bottom surface, an inner surface, an outer surface and a top surface configured for attachment to a carrier head, wherein the bottom surface includes a first portion and a second portion having different surface roughness.

A retaining ring comprising:

• an annular body having a bottom surface, an inner surface, an outer surface and a top surface configured for attachment to a carrier head, an inner edge between the inner surface and the bottom surface having a first radius of curvature, and an outer edge between the outer surface and the bottom surface having a second radius of curvature that is different from the first radius of curvature.

A retaining ring comprising:

• an annular body having a bottom surface, an inner surface, an outer surface and a top surface configured for attachment to a carrier head, wherein the bottom surface of the retaining ring includes polyamide-imide.