Reduction of hillocks prior to dielectric barrier deposition in cu damascene

Abstract

Unwanted hillocks arising in copper layers due to formation of overlying barrier layers may be significantly reduced by optimizing various process parameters, alone or in combination. A first set of process parameters may be controlled to pre-condition the processing chamber in which the barrier layer is deposited. A second set of process parameters may be controlled to minimize energy to which a copper layer is exposed during removal of CuO prior to barrier deposition. A third set of process parameters may be controlled to minimize the thermal budget after removal of the copper oxide.

1 - 3 . (canceled)  
     
     
         4 . A method of preconditioning a processing chamber that is to be utilized to form a barrier layer on top of a copper layer, the method comprising: 
 seasoning a processing chamber with a deposited material prior to introduction of a substrate bearing a copper layer; and    exposing the seasoned processing chamber to a plasma prior to introduction of a substrate bearing a copper layer.    
     
     
         5 . The method of  claim 4  wherein the plasma is generated in the processing chamber.  
     
     
         6 . The method of  claim 4  wherein the plasma is generated remote from the processing chamber.  
     
     
         7 . The method of  claim 4  wherein the plasma is generated from a gas comprising N2, N2O, NH3, or a noble gas.  
     
     
         8 . The method of  claim 4  further comprising: 
 introducing a substrate bearing a copper layer into the processing chamber; and    forming a barrier layer over the copper layer.    
     
     
         9 . The method of  claim 8  wherein forming the barrier layer comprises depositing a barrier layer selected from the group consisting of SiCN, oxygen doped SiC, SiN, TiN, Ta, TaN, and Ta/TaN.  
     
     
         10 . The method of  claim 8  further comprising: 
 from a gas distribution faceplate prior to receiving the substrate.    
     
     
         11 - 20 . (canceled)