Methods for polishing copper features of semiconductor devices structures

Abstract

A method for substantially simultaneously polishing a copper conductive structure of a semiconductor device structure and an adjacent barrier layer includes use of a slurry that is formulated so as to oxidize copper at substantially the same rate as or at a faster rate than a material of the barrier layer is oxidized. Thus, copper and the barrier layer material have substantially the same oxidation energies in the slurry or the oxidation energy of the barrier layer material in the slurry may be greater than that of copper. The slurry may be configured for use with a fixed-abrasive type polishing pad and, therefore, may be substantially abrasive-free.

1 . A method for chemical-mechanical polishing a copper structure and an adjacent barrier layer of a semiconductor device structure, comprising: 
 providing a semiconductor device structure including at least one recess formed in a surface thereof, a barrier layer lining at least the at least one recess, and a conductive layer comprising copper at least partially filling the at least one recess; and    substantially concurrently polishing the conductive layer and the barrier layer without removing the barrier layer at a substantially greater rate than the copper is removed.    
   
   
       2 . The method of  claim 1 , wherein substantially concurrently polishing comprises employing a slurry formulated to effect an oxidation rate of the barrier layer substantially the same as or less than an oxidation rate of the copper.  
   
   
       3 . The method of  claim 1 , wherein substantially concurrently polishing comprises employing a slurry formulated to provide substantially similar oxidation energies of the barrier layer and the copper.  
   
   
       4 . The method of  claim 3 , wherein employing the slurry comprises employing a slurry in which an oxidation energy of the barrier layer is from about 0.25 V greater than to about 0.20 V less than an oxidation energy of the copper.  
   
   
       5 . The method of  claim 1 , wherein substantially concurrently polishing comprises employing a slurry in which a removal rate of the material of the barrier layer is up to about ten times slower than a removal rate of the copper.  
   
   
       6 . The method of  claim 1 , wherein substantially concurrently polishing comprises employing a slurry in which a removal rate of the material of the barrier layer is about two to about four times slower than a removal rate of the copper.  
   
   
       7 . The method of  claim 1 , wherein providing the semiconductor device structure comprises providing a semiconductor device structure with the barrier layer comprising tungsten.  
   
   
       8 . The method of  claim 1 , wherein substantially concurrently polishing is effected at ambient temperature or a cooler temperature.  
   
   
       9 . A method for chemical-mechanical polishing a copper conductive structure and an adjacent barrier layer of a semiconductor device structure, comprising: 
 providing a semiconductor device structure including at least one recess formed in a surface thereof, a barrier layer lining at least the at least one recess, and a conductive layer comprising copper within the at least one recess; and    substantially concurrently polishing the barrier layer and the conductive layer without oxidizing a material of the barrier layer at a substantially greater rate than the copper is oxidized.    
   
   
       10 . The method of  claim 9 , wherein providing the semiconductor device structure comprises providing a semiconductor device structure with the barrier layer comprising tungsten.  
   
   
       11 . The method of  claim 9 , wherein substantially concurrently polishing comprises employing a polishing pad.  
   
   
       12 . The method of  claim 11 , wherein employing the polishing pad comprises employing a fixed-abrasive polishing pad.  
   
   
       13 . The method of  claim 9 , wherein substantially concurrently polishing comprises employing a slurry.  
   
   
       14 . The method of  claim 13 , wherein employing the slurry comprises employing a slurry formulated to oxidize the copper of the conductive layer at substantially the same rate as or a faster rate than the tungsten of the barrier layer is oxidized.  
   
   
       15 . The method of  claim 13 , wherein employing the slurry comprises employing a slurry formulated to provide substantially similar oxidation energies of the tungsten and the copper.  
   
   
       16 . The method of  claim 15 , wherein, in employing the slurry, the tungsten has an oxidation energy from about 0.25 V more to about 0.20 V less than the oxidation energy of the copper.  
   
   
       17 . The method of  claim 9 , wherein, during said substantially concurrently polishing, a material of the barrier layer is not removed at a substantially greater rate than the rate at which the copper is removed.  
   
   
       18 . The method of  claim 17 , wherein, during said substantially concurrently polishing, the material of the barrier layer is removed at a rate of as low as about one tenth the rate at which the copper is removed.  
   
   
       19 . The method of  claim 17 , wherein, during said substantially concurrently polishing, the material of the barrier layer is removed at a rate of about one fourth to about one half of the rate at which the copper is removed.  
   
   
       20 . A method for polishing a surface of a semiconductor device structure, the surface including a conductive structure including copper and a barrier layer adjacent the conductive structure, the method comprising substantially concurrently oxidizing a material of the barrier layer at substantially the same rate as or at a slower rate than a rate at which the conductive structure is oxidized.  
   
   
       21 . The method of  claim 20 , wherein substantially concurrently oxidizing is effected with a slurry.  
   
   
       22 . The method of  claim 21 , wherein substantially concurrently oxidizing comprises employing a slurry that is substantially free of abrasive particles.  
   
   
       23 . The method of  claim 22 , further comprising employing a fixed abrasive polishing pad.  
   
   
       24 . The method of  claim 20 , wherein substantially concurrently oxidizing comprises employing a slurry in which the copper and the material of the barrier layer exhibit substantially the same oxidation energies.  
   
   
       25 . The method of  claim 24 , wherein employing the slurry comprises employing a slurry in which an oxidation energy of the material of the barrier layer is from about 0.25 V more to about 0.20 V less than an oxidation energy of the copper.  
   
   
       26 . The method of  claim 24 , wherein employing the slurry comprises employing a slurry in which a removal rate of the material of the barrier layer is as low as about one tenth a removal rate of the copper.  
   
   
       27 . The method of  claim 24 , wherein employing the slurry comprises employing a slurry in which a removal rate of the material of the barrier layer is about one fourth to about one half a removal rate of the copper.  
   
   
       28 . The method of  claim 20 , comprising providing a semiconductor device structure with a barrier layer comprising tungsten.  
   
   
       29 . The method of  claim 20 , wherein substantially concurrently polishing is effected without substantially dissolving a portion of the barrier layer located beneath a remaining portion of the conductive structure.