Method and apparatus for polishing workpiece

Abstract

A workpiece such as a semiconductor wafer is polished by pressing the workpiece against a polishing surface under a predetermined pressure. A polished surface of the workpiece is processed by pressing the workpiece against a processing surface under a predetermined pressure while the processing surface makes circulatory translational motion along a predetermined path. The processing surface comprises a surface of a polishing cloth or a surface of an abrading plate, and the polished surface of the workpiece is further polished or cleaned.

1 . A method for polishing a pattern surface of a semiconductor wafer comprising: 
 main polishing said pattern surface by pressing said semiconductor wafer downwards against a main polishing surface comprising abrasive grains and a binder binding said abrasive grains;    finish polishing the main polished surface of said semiconductor wafer by pressing said semiconductor wafer downwards against a finish polishing surface comprising a polishing cloth; and    cleaning said finish polished surface of said semiconductor wafer, and then drying said cleaned finish polished surface of said semiconductor wafer.    
     
     
         2 . A method according to  claim 1 , wherein said main polishing, finish polishing, cleaning and drying processes are carried out in a single polishing apparatus.  
     
     
         3 . A method according to  claim 1 , wherein said main polishing surface is the surface of an abrading plate shaped as a circular disc.  
     
     
         4 . A method according to  claim 1 , wherein said main polished semiconductor wafer is washed before said finish polishing.  
     
     
         5 . A method according to  claim 1 , wherein said main polishing and said finish polishing are carried out by holding said semiconductor wafer by different top rings.  
     
     
         6 . A method according to  claim 1 , wherein the pressing force on said semiconductor wafer in said finish polishing process is equal to or lower than that in said main polishing process.  
     
     
         7 . A method according to  claim 1 , wherein said pattern surface comprises a wiring pattern.  
     
     
         8 . A method according to  claim 2 , wherein said cleaned and dried semiconductor wafer is transferred to a cassette.  
     
     
         9 . A method according to  claim 1 , wherein said abrading surface has a groove defined in the upper surface thereof.  
     
     
         10 . A method according to  claim 1 , wherein said abrasive grains comprise CeO 2 .  
     
     
         11 . A method according to  claim 1 , wherein said abrading surface comprises holes on its upper surface.  
     
     
         12 . A method according to  claim 1 , wherein said main polishing process is longer than said finish polishing process.  
     
     
         13 . A method according to  claim 1 , wherein said finish polished semiconductor wafer is washed in one or more cleaning machines and then dried.  
     
     
         14 . A method according to  claim 1 , wherein said semiconductor wafer is reversed before it is main polished.  
     
     
         15 . A method according to  claim 1 , wherein a polishing liquid containing abrasive grains is supplied to said finish polishing surface.  
     
     
         16 . A method for polishing a surface of a semiconductor wafer comprising: 
 delivering said semiconductor wafer from a cassette to an abrading plate, said semiconductor wafer being reversed so as to face said surface to be polished downwards while delivering;    main polishing said surface of said semiconductor wafer by pressing said semiconductor wafer downwards against an abrading surface of an abrading plate, said abrading plate comprising abrasive grains and a binder binding said abrasive grains; and    finish polishing the polished surface of said semiconductor wafer by pressing said semiconductor wafer downwards against a finish polishing surface.    
     
     
         17 . A method according to  claim 16 , wherein said semiconductor wafer is delivered by using a robot.  
     
     
         18 . A method according to  claim 16 , wherein said semiconductor wafer is reversed by a reversing machine.  
     
     
         19 . A method according to  claim 16 , wherein said semiconductor wafer is a patterned semiconductor wafer.  
     
     
         20 . A method according to  claim 19 , wherein said patterned semiconductor wafer comprises a wiring pattern.  
     
     
         21 . A method according to  claim 16 , further comprising cleaning and then drying said finish polished surface of said semiconductor wafer.  
     
     
         22 . A method according to  claim 16 , wherein said main polished semiconductor wafer is washed before said finish polishing.  
     
     
         23 . A method according to  claim 16 , wherein said main polishing and said finish polishing are carried out by holding said semiconductor wafer by different top rings.  
     
     
         24 . A method according to  claim 16 , wherein the pressing force on said semiconductor wafer in said finish polishing is equal to or lower than that in said main polishing.  
     
     
         25 . A method according to  claim 21 , wherein said main polishing, finish polishing, cleaning and drying processes are carried out in a single polishing apparatus.  
     
     
         26 . A method according to  claim 25 , wherein said semiconductor wafer is supplied from and returned to the same cassette.  
     
     
         27 . A method according to  claim 16 , wherein said abrading surface has a groove defined in the upper surface thereof.  
     
     
         28 . A method according to  claim 16 , wherein said abrasive grains comprise CeO 2 .  
     
     
         29 . A method according to  claim 16 , wherein said abrading surface comprises holes on its upper surface.  
     
     
         30 . A method according to  claim 16 , wherein said main polishing process is longer than said finish polishing process.  
     
     
         31 . A method according to  claim 21 , wherein said finish polished semiconductor wafer is washed in one or more cleaning machines and then dried.  
     
     
         32 . A method according to  claim 16 , wherein said abrading plate is a circular disc.  
     
     
         33 . A method according to  claim 16 , wherein said finish polishing surface is formed on a polishing cloth.  
     
     
         34 . A method according to  claim 16 , wherein a polishing liquid containing abrasive grains is supplied to said finish polishing surface.  
     
     
         35 . A method for polishing a surface of a semiconductor wafer comprising: 
 delivering said semiconductor wafer from a cassette to a main polishing unit;    main polishing said surface of said semiconductor wafer by pressing said semiconductor wafer downwards against an abrading surface of an abrading plate in said main polishing unit, said abrading plate comprising abrasive grains and a binder binding said abrasive grains; and    finish polishing the polished surface of said semiconductor wafer by pressing said semiconductor wafer downwards against a finish polishing surface in a finish polishing unit.    
     
     
         36 . A method for polishing a pattern surface of a semiconductor wafer comprising: 
 polishing said pattern surface by pressing said semiconductor wafer against a polishing surface comprising abrasive grains and a binder binding said abrasive grains; and    polishing the polished surface of said semiconductor wafer by pressing said semiconductor wafer against a polishing surface comprising a polishing cloth while supplying deionized water to said polishing surface comprising said polishing cloth.    
     
     
         37 . A method for polishing a pattern surface of a semiconductor wafer comprising: 
 polishing said pattern surface by pressing said semiconductor wafer against a polishing surface comprising abrasive grains and a binder binding said abrasive grains; and    polishing the polished surface of said semiconductor wafer by pressing said semiconductor wafer against a polishing surface comprising a polishing cloth while supplying deionized water or a chemical to said polishing surface comprising said polishing cloth.    
     
     
         38 . A method for polishing a surface of a workpiece comprising: 
 polishing said surface by pressing the workpiece against a first polishing surface comprising abrasive grains and a binder binding said abrasive grains; and    further processing said polished surface of the workpiece while supplying deionized water.    
     
     
         39 . A method according to  claim 38 , wherein said further processing is a rubbing process comprising pressing said polished surface of the workpiece against a rubbing surface.  
     
     
         40 . A method according to  claim 38 , wherein said further processing is finish polishing comprising pressing said polished surface of the workpiece against a polishing cloth.  
     
     
         41 . A method according to  claim 38 , wherein the workpiece comprises a semiconductor wafer having a pattern surface thereon.  
     
     
         42 . A method according to  claim 41 , wherein protruded regions of the pattern surface of the semiconductor wafer can be selectively removed to produce an overall flat surface of the polished semiconductor wafer.  
     
     
         43 . A method according to  claim 38 , wherein a pressing force applied to the workpiece during said further processing is equal to or lower than a pressing force for pressing the workpiece against said first polishing surface.  
     
     
         44 . A method according to  claim 38 , wherein a first polishing process by said first polishing surface is longer than said further processing.  
     
     
         45 . A method according to  claim 38 , wherein the workpiece is washed between said polishing process and said further processing process.  
     
     
         46 . A method according to  claim 38 , wherein the workpiece is turned over before attachment to a top ring for holding the workpiece.  
     
     
         47 . A method according to  claim 38 , further comprising several cleaning steps for cleaning the workpiece after said further processing.  
     
     
         48 . A method according to  claim 38 , further comprising a drying step for drying the polished workpiece.  
     
     
         49 . A method for polishing a surface of a semiconductor wafer comprising: 
 delivering the wafer from a cassette to a first polishing table;    reversing the wafer;    attaching the wafer to a top ring, which holds the wafer during a polishing operation;    rotating and pressing the wafer by said top ring against a first polishing surface of said first polishing table, said first polishing surface comprising abrasive grains and a binder binding said abrasive grains, while supplying a polishing solution;    cleaning the first polished wafer;    delivering the wafer to a second polishing table;    further processing the polished surface of the wafer with the second polishing table, having a polishing cloth, while supplying deionized water or a chemical;    cleaning and then drying the polished wafer;    reversing the wafer; and    delivering the wafer to the cassette.    
     
     
         50 - 64 . (canceled)