Hybrid subtractive etch/metal fill process for fabricating interconnects

Abstract

In one example, a method for fabricating an integrated circuit includes patterning a layer of a first conductive metal, via a subtractive etch process, to form a plurality of lines for connecting semiconductor devices on the integrated circuit. A large feature area is formed outside of the plurality of conductive lines via a metal fill process using a second conductive metal.

1 .- 4 . (canceled) 
     
     
         5 . A method for fabricating an integrated circuit, the method comprising:
 patterning a layer of a first conductive metal, via a subtractive etch process, to form a plurality of conductive lines for connecting semiconductor devices on the integrated circuit, wherein the patterning the layer of the first conductive metal comprises:
 depositing a first liner layer over a silicon wafer; 
 depositing the layer of the first conductive metal over the first liner layer; and 
 removing a portion of the layer of the first conductive metal down to the first liner layer; and 
 lining the plurality of lines with a second liner layer; and 
   forming a large feature area outside of the plurality of conductive lines via a metal fill process performed after the subtractive etch process, using a second conductive metal, wherein the forming the large feature area comprises:
 depositing an interlayer dielectric layer over the second liner layer; 
 patterning the interlayer dielectric layer to create a recess; 
 lining the recess with a third liner layer; and 
 depositing the second conductive metal in the recess to create the large feature area. 
   
     
     
         6 . The method of  claim 5 , wherein the metal fill process is an electroplating or vapor deposition process. 
     
     
         7 . The method of  claim 5 , wherein the large feature area is configured to house an electrical pad. 
     
     
         8 . The method of  claim 7 , wherein the large feature area overlaps with a portion of the plurality of conductive lines. 
     
     
         9 .- 20 . (canceled) 
     
     
         21 . The method of  claim 5 , wherein at least one of the first conductive metal and the second conductive metal comprises a metal alloy. 
     
     
         22 . The method of  claim 5 , wherein at least one of the first conductive metal and the second conductive metal comprises copper. 
     
     
         23 . The method of  claim 5 , wherein at least one of the first conductive metal and the second conductive metal comprises gold. 
     
     
         24 . The method of  claim 5 , wherein at least one of the first conductive metal and the second conductive metal comprises silver. 
     
     
         25 .- 31 . (canceled)