Retaining ring for wafer polishing

A retaining ring for retaining a disk-shaped object during polishing of a surface of the object, comprising a circular inner circumference formed from a flexible material, the inner circumference being operable to distend in response to lateral force exerted during polishing to form a continuous arc of contact with the object during polishing, the arc of contact covering at least approximately 30° and less than 360° of a circumference of the object.

A polishing machine for polishing a surface of an object, the polishing machine comprising:

• a polishing surface;
• and
• a holder operable to hold the object against the polishing surface, the holder having a support structure operable to support the object in contact with the polishing surface, the holder further having an annular retaining ring operable to retain the object in alignment with the support structure, the retaining ring having a plurality of projections projecting inwardly from an inner circumference of the retaining ring, the projections having tips defining a circle, the circle having a diameter greater than a diameter of the object, the projections being situated such that the object contacts fewer than all of the projections during polishing.

A wafer holder operable to hold a wafer against a polishing surface during polishing of the wafer, the wafer holder comprising:

• a support structure in contact with the back side of the wafer, the support structure being operable to support the wafer against the polishing surface;
• and
• an annular retaining ring operable to retain the wafer in alignment with the support structure, the retaining ring having a plurality of projections projecting inwardly from an inner circumference of the retaining ring, the projections having tips defining a circle, the circle having a diameter greater than a diameter of the object, the projections being situated such that the object contacts fewer than all of the projections during polishing.