Polishing apparatus

Abstract

A polishing apparatus which can remove slurry which has entered into a gap between an elastic membrane for pressing a substrate such as a wafer and a retaining ring is disclosed. The polishing apparatus includes a top ring which has an elastic membrane configured to form a pressure chamber for pressing the substrate against a polishing pad, and a retaining ring disposed around the elastic membrane and configured to press the polishing pad, a top ring rotating device configured to rotate the top ring about an axis of the top ring, and a cleaning brush configured to be brought into contact with a peripheral portion of a lower surface and an outer circumferential surface of the elastic membrane.

What is claimed is: 
     
         1 . A polishing apparatus, comprising:
 a polishing table configured to support a polishing pad;   a top ring which has an elastic membrane configured to form a pressure chamber for pressing a substrate against the polishing pad, and a retaining ring disposed around the elastic membrane and configured to press the polishing pad;   a top ring rotating device configured to rotate the top ring about an axis of the top ring; and   a cleaning brush configured to be brought into contact with a peripheral portion of a lower surface and an outer circumferential surface of the elastic membrane.   
     
     
         2 . The polishing apparatus according to  claim 1 , further comprising:
 a cleaning liquid supply nozzle configured to supply a jet of a cleaning liquid to the cleaning brush.   
     
     
         3 . The polishing apparatus according to  claim 1 , further comprising:
 a cleaning brush movement mechanism configured to move the cleaning brush between a cleaning position below the top ring and a standby position outside of the top ring.   
     
     
         4 . The polishing apparatus according to  claim 1 , wherein the cleaning brush is brought into contact with an inner circumferential surface of the retaining ring. 
     
     
         5 . The polishing apparatus according to  claim 1 , wherein the cleaning brush is brought into contact with a lower surface of the retaining ring. 
     
     
         6 . The polishing apparatus according to  claim 1 , wherein the cleaning brush is a first cleaning brush, and a second cleaning brush configured to be brought into contact with a zone more inner than the peripheral portion in the lower surface of the elastic membrane is further provided.