Method and apparatus for copper electroplating

Abstract

A method and apparatus for a copper electroplating procedure, wherein a first additive is preferentially adsorbed onto the field region of a substrate and a second additive is preferentially adsorbed onto the surfaces of at least one recessed region of the substrate, is provided. The first additive is more resistive to the electrodeposition relative to the second additive such that the recessed regions are filled at a faster rate than a layer is deposited on the field region.

1 . A method for electroplating a substrate having a field region and at least one recessed region formed therein, said method comprising:
 preferentially adsorbing a first additive to surfaces of said at least one recessed region;   preferentially adsorbing a second additive to said field region;   subsequently immersing said substrate into a plating bath; and   performing an electroplating procedure to deposit copper onto said substrate, wherein said preferentially adsorbed first and second additives cause copper to be electroplated into said at least one recessed region faster than copper is electroplated onto said field region.   
   
   
       2 . The method of  claim 1 , wherein preferentially adsorbing said first additive includes immersing said substrate into a tank containing said first additive. 
   
   
       3 . The method of  claim 2 , wherein preferentially adsorbing said second additive includes immersing said substrate into a second tank containing said second additive. 
   
   
       4 . The method of  claim 1 , wherein preferentially adsorbing said first additive includes using a spin-on technique to distribute a first additive-containing solution over said substrate. 
   
   
       5 . The method of  claim 1 , wherein preferentially adsorbing said second additive includes using a spin-on technique to distribute a second additive-containing solution over said substrate. 
   
   
       6 . The method of  claim 1 , wherein said first additive is an accelerator. 
   
   
       7 . The method of  claim 1 , wherein said second additive is a leveler. 
   
   
       8 . The method of  claim 1 , wherein said plating bath includes copper sulfate (CuSO 4 ). 
   
   
       9 . The method of  claim 8 , wherein said plating bath further includes a suppressor additive. 
   
   
       10 . The method of  claim 8 , wherein said plating bath does not include an accelerator additive. 
   
   
       11 . The method of  claim 1 , wherein said substrate is rinsed with de-ionized water prior to being immersed in said plating bath and after preferentially adsorbing said first and second additives. 
   
   
       12 . A method for electroplating a substrate comprising:
 immersing said substrate into a first tank containing an electrolyte solution, said electrolyte solution including a first additive and a second additive, and said first additive is preferentially adsorbed onto surfaces of at least one recessed region formed in said substrate and said second additive is preferentially adsorbed onto a field region of said substrate;   rinsing excess of said electrolyte solution from said substrate; and   after rinsing, immersing said substrate into a plating bath for an electroplating procedure, wherein said first additive provides less resistance to electrodeposition of copper than said second additive.   
   
   
       13 . The method of  claim 12 , wherein one of said at least one recessed region has an opening measuring less than one micrometer. 
   
   
       14 . The method of  claim 12 , wherein one of said at least one recessed region has an opening measuring at least one micrometer. 
   
   
       15 . The method of  claim 12 , wherein one of said at least one recessed region has an opening measuring less than one micrometer and a second of said at least one recessed region has an opening measuring at least one micrometer. 
   
   
       16 . The method of  claim 12 , wherein said substrate is immersed in said first tank between about 10 seconds and about 200 seconds. 
   
   
       17 . The method of  claim 12 , wherein said plating bath includes at least one additive different than said first additive and said second additive. 
   
   
       18 . The method of  claim 12  further comprising removing said electrodeposited layer from said field region. 
   
   
       19 . An apparatus for electroplating a substrate having a field region and at least one recessed region formed therein, said apparatus comprising:
 a first tank containing at least a first additive, wherein said substrate is immersable into said first tank, said first additive configured to be preferentially adsorbed onto one of said field region and surfaces of said at least one recessed region;   a second tank containing at least a second additive, wherein said substrate is immersable into said second tank, said second additive configured to be preferentially adsorbed onto the other of said field region and surfaces of said at least one recessed region; and   a third tank containing a plating bath into which said substrate is immersable for an electroplating procedure, wherein an anode plate is disposed within said plating bath, and said anode plate is operatively connectable to said substrate through said plating bath to form an electrical circuit for said electroplating procedure.   
   
   
       20 . The apparatus of  claim 19 , wherein said first additive provides a film more resistive to electroplating than said second additive. 
   
   
       21 . The apparatus of  claim 19 , wherein said first and second additives are configured to permit electroplating in said at least one recessed region at a faster rate than onto said field region. 
   
   
       22 . The apparatus of  claim 19 , wherein said at least one recessed region has an opening diameter, and said first and second additives are configured such that electroplating produces a thin film on said field region having a thickness less than about 40% of said opening diameter. 
   
   
       23 . An apparatus for electroplating a substrate having a field region and at least one recessed region formed therein, said apparatus comprising:
 a spin-on mechanism configured to preferentially adsorb a first additive onto one of said field region and surfaces of said at least one recessed region and preferentially adsorb a second additive onto the other of said field region and surfaces of said at least one recessed region; and   a tank containing a plating bath into which said substrate is immersable for an electroplating procedure, wherein an anode plate is disposed within said plating bath, and said anode plate is operatively connectable to said substrate through said plating bath to form an electrical circuit for said electroplating procedure.   
   
   
       24 . The apparatus of  claim 23 , wherein said spin-on mechanism is further configured to rinse said substrate prior to immersing said substrate into said tank.