CMP-apparatus retainer ring and manufacturing method thereof, and CMP apparatus

Abstract

A retainer ring is provided which is capable of, effectively in practice, restraining the time taken for a break-in polish to the minimum. This retainer ring 8: is disposed inside of a holding head 4 in a CMP apparatus 1 which polishes a wafer W chemically and mechanically; has a ring shape so as to surround the periphery of the wafer W; presses a polish surface 3 a of a polish pad 3; is made of an engineering plastic material such as PPS; and has a pressure surface 8 a for pressing the polish surface 3 a of the polish pad 3 whose surface roughness is a center-line average roughness (Ra) of 0.01 μm or below.

1 . A CMP-apparatus retainer ring which, in a CMP apparatus that includes a polish pad disposed on a base and a holding head holding a wafer and pressing the wafer against the polish pad and that polishes the wafer chemically and mechanically: is provided inside of the holding head; has a ring shape so as to surround the periphery of the wafer; and presses the polish surface of the polish pad, characterized in that: 
 the retainer ring is made of an engineering plastic material; and the surface roughness of a pressure surface for pressing the polish surface of the polish pad is a center-line average roughness of 0.01 μm or below.    
     
     
         2 . The CMP-apparatus retainer ring according to  claim 1 , characterized in that: in the back surface of the retainer ring located at the back surface of the pressure surface, a portion to be held is formed; and the pressure surface is polished.  
     
     
         3 . A CMP-apparatus retainer-ring manufacturing method for, in a CMP apparatus that includes a polish pad disposed on a base and a holding head holding a wafer and pressing the wafer against the polish pad and that polishes the wafer chemically and mechanically, manufacturing an engineering-plastic retainer ring which is provided inside of the holding head, has a ring shape so as to surround the periphery of the wafer and presses the polish surface of the polish pad, characterized by including the steps of: 
 working a shaped surface other than a pressure surface for pressing the polish surface of the polish pad so that the shaped surface has a predetermined measurement;    holding the retainer ring without applying an external-circumference pressure and an internal-circumference pressure to the retainer ring; and    machining the pressure surface in this state, and polishing the pressure surface until the surface roughness thereof becomes a center-line average roughness of 0.01 μm or below.    
     
     
         4 . The CMP-apparatus retainer-ring manufacturing method according to  claim 3 , characterized in that: the polish pad disposed on the base, a pressing means for rotating the retainer ring and pressing the pressure surface thereof against the polish pad and a slurry supplying means for supplying slurry to the polish pad are provided; and the polishing is conducted by a polishing apparatus which regulates a pressure and a rotational speed given by the pressing means and a slurry supply given by the slurry supplying means.  
     
     
         5 . The CMP-apparatus retainer-ring manufacturing method according to  claim 4 , characterized in that before the polishing is conducted, break-in working is conducted by attaching a break-in retainer ring to the polishing apparatus.  
     
     
         6 . The CMP-apparatus retainer-ring manufacturing method according to any one of  claims 3  to  5 , characterized in that the machining and the polishing are conducted with holding only the side of the back surface of the retainer ring located at the back surface of the pressure surface.  
     
     
         7 . The CMP-apparatus retainer-ring manufacturing method according to  claim 6 , characterized in that: a portion to be held is formed in the back surface of the retainer ring; the retainer ring is held by a machining jig which includes a holding portion that holds this portion to be held; and the machining is conducted in this state.  
     
     
         8 . The CMP-apparatus retainer-ring manufacturing method according to  claim 7 , characterized in that: the machining jig holding the retainer ring is supported by a polishing jig which supports the side of the back surface of the machining jig located at the back surface of the holding portion; and the polishing is conducted in this state.  
     
     
         9 . A CMP-apparatus retainer-ring machining jig which is the machining jig used in the CMP-apparatus retainer-ring manufacturing method according to  claim 7 , characterized in that, 
 the machining jig: has a flat-board shape; and in an attachment surface which comes into surface contact with the back surface of the retainer ring, includes the holding portion which holds the portion to be held that is formed in the back surface of the retainer ring.    
     
     
         10 . A CMP-apparatus retainer-ring polishing jig which is the polishing jig used in the CMP-apparatus retainer-ring manufacturing method according to  claim 8 , characterized in that, 
 the polishing jig: has a flat-board shape; and includes a concave supporting portion which houses the side of the back surface of the machining jig located at the back surface of the attachment surface, is fitted to the peripheral surface of the machining jig and supports the back surface of the machining jig.    
     
     
         11 . A CMP apparatus which: includes a polish pad disposed on a base and a holding head that holds a wafer and presses the wafer against the polish pad, this holding head having a retainer ring which has a ring shape so as to surround the periphery of the wafer and presses the polish surface of the polish pad; and polishes the wafer chemically and mechanically, characterized in that: 
 the retainer ring is made of an engineering plastic material; and the surface roughness of a pressure surface of the retainer ring for pressing the polish surface of the polish pad is set at a center-line average roughness of 0.01 μm or below.