Polishing apparatus

Abstract

A polishing apparatus has a turntable with a polishing cloth attached thereto and a top ring for holding and pressing a workpiece to be polished against the polishing cloth under a certain pressure. The polishing apparatus also has a first dressing unit having a contact-type dresser for dressing the polishing cloth by bringing the contact-type dresser in contact with the polishing cloth, and a second dressing unit having a noncontact-type dresser for dressing the polishing cloth with a fluid jet applied therefrom to the polishing cloth. The contact-type dresser comprises a diamond dresser or an SiC dresser.

What is claimed is:  
     
         1 . A method of polishing a workpiece in a polishing apparatus, comprising: 
 conditioning a polishing surface by a contact-type dresser for initial conditioning before starting using said polishing surface;    polishing a workpiece by bringing said workpiece into contact with said polishing surface after said conditioning; and    dressing said polishing surface after said polishing by a noncontact-type dresser for removing ground-off particles of said workpiece.    
     
     
         2 . A method according to  claim 1 , wherein said noncontact-type dresser and said contact-type dresser are provided in said polishing apparatus.  
     
     
         3 . A method according to  claim 1 , wherein said noncontact-type dresser comprises a plurality of fluid jet nozzles for ejecting fluid jets.  
     
     
         4 . A method according to  claim 3 , wherein the pressure of each of said nozzles is variable.  
     
     
         5 . A method according to  claim 1 , wherein said contact-type dresser comprises a diamond dresser.  
     
     
         6 . A method according to  claim 1 , wherein said polishing surface is dressed by said contact-type dresser before said dressing of said polishing surface by said noncontact-type dresser.  
     
     
         7 . A method according to  claim 1 , wherein said noncontact-type dresser is angularly movable to a standby position located outwardly of said polishing surface.  
     
     
         8 . A method according to  claim 7 , wherein said contact-type dresser is angularly movable to a standby position located outwardly of said polishing surface.  
     
     
         9 . A method of polishing workpieces in a polishing apparatus, comprising: 
 attaching a member having a polishing surface to a table;    conditioning said polishing surface by a contact-type dresser for initial conditioning before starting using said polishing surface;    polishing workpieces repeatedly by bringing each of said workpieces into contact with said polishing surface after said conditioning while supplying an abrasive liquid in said polishing; and    dressing said polishing surface between said polishing of said workpieces by a noncontact-type dresser for removing ground-off particles of said workpieces.    
     
     
         10 . A method according to  claim 9 , further comprising holding said each of said workpieces by a vacuum.  
     
     
         11 . A method according to  claim 9 , wherein said noncontact-type dresser comprises a plurality of fluid jet nozzles for ejecting fluid jets.  
     
     
         12 . A method according to  claim 1  wherein the pressure of each of said nozzles is variable.  
     
     
         13 . A method according to  claim 9 , wherein said contact-type dresser comprises a diamond dresser.  
     
     
         14 . A method according to  claim 9 , wherein said polishing surface is dressed by said contact-type dresser before said dressing of said polishing surface by said noncontact-type dresser.  
     
     
         15 . A method of polishing a workpiece in a polishing apparatus, comprising: 
 attaching a member having a polishing surface to a table;    conditioning said polishing surface for initial conditioning before starting using said polishing surface;    polishing a workpiece by bringing said workpiece into contact with said polishing surface after said conditioning; and    dressing said polishing surface after said polishing for removing ground-off particles of said workpiece.