Retainer ring and wafer polishing system including the retainer ring

A retainer ring comprising:

• a coupling block coupled to a polishing head;
• and
• a mold block coupled to the coupling block, configured to support a wafer positioned on a polishing pad and to contact the polishing pad,
• wherein the mold block comprises:
• a body coupled to the coupling block;
• and
• a pad contact disposed on the body and configured to contact the polishing pad, and
• wherein the pad contact comprises:
• a connection passage formed along a circumferential direction of the body to divide the pad contact into an inner pad contact and an outer pad contact;
• a plurality of inlet passages extending from the connection passage to an outer circumferential side of the pad contact and configured to inflow slurry into the connection passage;
• a plurality of outlet passages extending from the connection passage to an inner circumferential side of the pad contact and configured to discharge slurry from the connection passage;
• and
• a plurality of guide passages located outside the pad contact at a rear side in a rotational direction of the polishing head and in communication with respective ones of the plurality of outlet passages.

A wafer polishing system comprising:

• a polishing pad;
• a polishing head disposed over the polishing pad and configured to press a wafer against the polishing pad;
• and
• a retainer ring mounted to the polishing head and configured to support the wafer,
• wherein the retainer ring comprises:
• a coupling block coupled to the polishing head;
• and
• a mold block coupled to the coupling block, positioned on the polishing pad to support the wafer and contact the polishing pad,
• wherein the mold block comprises:
• a body coupled to the coupling block;
• a pad contact disposed on the body and configured to contact the polishing pad;
• a plurality of slurry passages formed in the pad contact and configured to transfer slurry from an outer circumferential side of the body to an inner circumferential side of the body;
• a plurality of slurry guides respectively located outside the pad contact at a rear side, in a rotational direction of the polishing head, of the pad contact and interconnected to the plurality of slurry passages;
• and
• an auxiliary slurry passage formed in the pad contact, and intersected to plurality of slurry passages.