Patent attributes
Apparatus and methods relating to chemical mechanical polishing (CMP) are described herein. An edge load ring (ELR) is configured to fit inside a retaining ring of a CMP head. The ELR includes an annular body having an inner surface and an outer surface opposite the inner surface, the outer surface having a diameter configured to slip inside a retaining ring. The annular body includes a body portion formed from a first material and a bottom projection extending below the body portion. The bottom projection has a bottom surface facing away from the body portion, and the bottom projection is formed form a second material different from the first material. The annular body includes a venting feature formed through the annular body, the venting feature being in fluid communication between the inner and outer surfaces.
