Substrate polishing apparatus and substrate polishing method

Abstract

A substrate polishing apparatus wherein a semiconductor substrate is held by a top ring 10 - 2 or 11 - 2 and is pressed against a polishing surface of a polishing table 10 - 1 or 10 - 2 . A surface to be polished of the semiconductor substrate is polished by a relative movement between the semiconductor substrate and the polishing surface. The apparatus includes a pressing force changing mechanism for changing a pressing force for pressing the semiconductor substrate, a relative movement seed changing mechanism for changing the number of revolutions of the top ring and/or the polishing table, and a control mechanism. The control mechanism performs the polishing through plural polishing processes on the polishing table 10 - 1 or 10 - 2 while changing the pressing force and the number of revolutions.

1 . A substrate polishing apparatus comprising: 
 a polishing table having a polishing surface; and    a top ring for holding a substrate;    wherein a semiconductor substrate held by said top ring is pressed against said polishing surface of said polishing table and a surface to be polished of the semiconductor substrate is polished by a relative movement between the semiconductor substrate and said polishing surface, and said semiconductor substrate has a copper plating film layer formed on a barrier layer;    the apparatus further comprising:    pressing force changing mechanism for changing a pressing force for pressing the semiconductor substrate;    revolution number changing mechanism for changing the revolution number of the top ring and/or the polishing table; and    control means;    wherein said control means performs plural polishing processes on the same polishing table while changing the pressing force and the revolution number through said pressing force changing mechanism and said revolution number changing mechanism,    the apparatus further comprising: an eddy current sensor and an optical sensor within said polishing table, wherein the eddy current sensor measures a film thickness of the copper plating film layer until the film thickness of the copper plating film layer reaches a predetermined film thickness which is measurable by the optical sensor, and the optical sensor measures the film thickness of the copper plating film layer when the film thickness of the copper plating film layer reaches the predetermined film thickness or less than it.    
   
   
       2 . The substrate polishing apparatus according to  claim 1 , further comprising dressing means for dressing said polishing surface of said polishing table or cleaning means for cleaning said polishing surface of said polishing table, and wherein said control means controls said dressing means or said cleaning means between the plural polishing processes to effect dressing or cleaning of said polishing surface of said polishing table.  
   
   
       3 . A substrate polishing method in which a semiconductor substrate held by a top ring is pressed against a polishing surface of a polishing table and a surface to be polished of the semiconductor substrate is polished by a relative movement between the semiconductor substrate and said polishing surface, wherein: 
 said semiconductor substrate has a copper plating film layer formed on a barrier layer, the semiconductor substrate is polished on the same polishing table through plural polishing processes while changing a pressing force for pressing the semiconductor substrate and the number of revolutions of said top ring and/or said polishing table,    during the plural polishing processes, the eddy current sensor measures the film thickness of the copper plating film layer until the film thickness of the copper plating film layer reaches a predetermined film thickness which is measurable by the optical sensor, and the optical sensor measures the film thickness of the copper plating film layer when the film thickness of the copper plating film layer reaches the predetermined film thickness or less than it.    
   
   
       4 . The substrate polishing method according to  claim 3 , wherein, when said plural polishing processes are performed, the polishing is effected while adding polishing liquid and/or reagent liquid having pH at the same side as pH 7.  
   
   
       5 . The substrate polishing method according to  claim 3 , wherein, when said plural polishing processes are performed, the polishing is effected by using same abrasive grain.  
   
   
       6 . The substrate polishing method according to  claim 3 , wherein the polishing surface of the polishing table is cleaned between the plural stage polishing processes, and after the polishing surface is cleaned, the next stage polishing process is performed.