Two step method for filling holes with copper

Abstract

A method of filling trenches or vias on a semiconductor workpiece surface with copper using sputtering techniques. A copper wetting layer and a copper fill layer may both be applied by sputtering techniques. The thin wetting layer of copper is applied at a substrate surface temperature ranging between about 20° C. to about 250° C., and subsequently the temperature of the substrate is increased, with the application of the sputtered copper fill layer beginning at above at least about 200° C. and continuing while the substrate temperature is increased to a temperature as high as about 600° C. Preferably the substrate temperature during application of the sputtered fill layer ranges between about 300° C. and about 500° C.

1 . A method of filling copper into a hole formed in a dielectric layer in a substrate, comprising the steps of: 
 a first step performed in a first reactor of depositing copper into said hole to form a copper layer on walls of said hole to a thickness of no more than 100 nm and leaving a reduced-sized hole; and    a second step performed in a second reactor which is a first sputter reactor of sputtering copper to fill said reduce-sized hole with copper.    
   
   
       2 . The method of  claim 1 , wherein said first reactor is a CVD reactor.  
   
   
       3 . The method of  claim 1 , wherein said first reactor is a second sputter reactor.  
   
   
       4 . The method of  claim 3 , wherein said first step includes RF biasing a applying an RF bias to a platen supporting said substrate.  
   
   
       5 . The method of  claim 4 , wherein a high density plasma is produced in said first step.  
   
   
       6 . The method of  claim 3 , wherein a high density plasma is produced in said first step.