Polishing apparatus

Abstract

A polishing apparatus is used to polish a workpiece such as a semiconductor wafer. The polishing apparatus includes a polishing table having a polishing surface, a dresser for dressing the polishing surface, a substrate holder for holding and pressing a substrate against the polishing surface to polish the substrate with relative movement between the polishing surface and the substrate. The dresser includes a first dressing member and a second dressing member. The first dressing member has a circular shape having a diameter larger than a diameter of the substrate. The second dressing member is shaped so as to surround the first dressing member. The first dressing member and the second dressing member are operable to come into contact with the polishing surface independently of each other.

1 . A polishing apparatus, comprising: 
 a polishing table having a polishing surface;    a dresser for dressing said polishing surface;    a substrate holder for holding and pressing a substrate against said polishing surface to polish the substrate with relative movement between said polishing surface and the substrate,    wherein said dresser includes a first dressing member and a second dressing member,    said first dressing member has a circular or disk shape having a diameter larger than a diameter of the substrate,    said second dressing member is shaped so as to surround said first dressing member, and    said first dressing member and said second dressing member are operable to come into contact with said polishing surface independently of each other.    
   
   
       2 . The polishing apparatus according to  claim 1 , wherein: 
 said first dressing member and said second dressing member have rotating shafts, respectively;    said rotating shafts of said first dressing member and said second dressing member are concentrically arranged and are rotatable independently of each other.    
   
   
       3 . The polishing apparatus according to  claim 1 , wherein a cut rate of said polishing surface by said first dressing member is lower than that by said second dressing member.  
   
   
       4 . The polishing apparatus according to  claim 1 , wherein said first dressing member is operable to dress said polishing surface of said polishing table during polishing of the substrate.  
   
   
       5 . The polishing apparatus according to  claim 1 , wherein said first dressing member and said second dressing member are operable to control a pressing force applied to said polishing surface of said polishing table independently of each other.  
   
   
       6 . The polishing apparatus according to  claim 1 , wherein said first dressing member includes a fluid passage through which a cooling or heating medium circulates.  
   
   
       7 . The polishing apparatus according to  claim 6 , further comprising a temperature controller for adjusting and controlling a temperature of the cooling or heating medium circulating said fluid passage.  
   
   
       8 . A polishing apparatus, comprising: 
 a polishing table having a polishing surface;    a dresser for dressing said polishing surface;    a substrate holder for holding and pressing a substrate against said polishing surface to polish the substrate with relative movement between said polishing surface and the substrate,    wherein said dresser includes a circular holding member for holding a circular dummy substrate, and a dressing member arranged around said circular holding member.    
   
   
       9 . The polishing apparatus according to  claim 8 , wherein: 
 said circular holding member and said dressing member have rotating shafts, respectively; and    said rotating shafts are concentrically arranged and are rotatable independently of each other.    
   
   
       10 . The polishing apparatus according to  claim 8 , wherein said circular holding member includes therein a fluid passage through which a cooling or heating medium circulates.  
   
   
       11 . The polishing apparatus according to  claim 10 , wherein said circular holding member is operable to press the dummy substrate against said polishing surface of said polishing table during polishing of the substrate.  
   
   
       12 . The polishing apparatus according to  claim 11 , wherein: 
 said polishing surface of said polishing table comprises a surface of a polishing pad attached to an upper surface of said polishing table; and    said polishing apparatus is operable such that, after said polishing pad is replaced with a new polishing pad, said dummy substrate held by said circular holding member and said dressing member are pressed against a polishing surface of said new polishing pad to thereby break in said polishing surface of said new polishing pad.    
   
   
       13 . The polishing apparatus according to  claim 8 , wherein a SiC wafer is used as the dummy substrate.  
   
   
       14 . The polishing apparatus according to  claim 8 , wherein said circular holding member is operable to press the dummy substrate against said polishing surface of said polishing table during polishing of the substrate.