Semiconductor structure and method for making same

Abstract

One or more embodiments relate to a method for making a semiconductor structure, comprising: providing a workpiece; forming a barrier layer over the workpiece; forming a separation layer over the barrier layer; forming a conductive layer over the separation layer; and wet etching the conductive layer.

What is claimed is: 
     
         1 . A semiconductor structure comprising:
 a workpiece;   a barrier layer overlying said workpiece;   a separation layer overlying said barrier layer, said separation layer essentially lacking tungsten; and   a conductive layer overlying said separation layer.   
     
     
         2 . The structure of  claim 1 , wherein said barrier layer comprises titanium. 
     
     
         3 . The structure of  claim 1 , wherein said conductive layer comprises copper. 
     
     
         4 . The structure of  claim 1 , wherein said barrier layer comprises tungsten. 
     
     
         5 . The structure of  claim 4 , wherein said barrier layer comprises titanium-tungsten alloy. 
     
     
         6 . The structure of  claim 1 , wherein said separation layer comprises titanium metal 
     
     
         61 . The structure of  claim 1 , wherein said separation layer comprises a carbon allotrope. 
     
     
         7 . The structure of  claim 1 , wherein said conductive layer comprises copper metal and/or copper alloy. 
     
     
         8 . A semiconductor structure comprising:
 a barrier layer disposed over a workpiece, said barrier layer comprising the chemical element tungsten;   a separation layer disposed over and in direct contact with said barrier layer, said separation layer essentially lacking the chemical element tungsten, said separation layer comprising at least one material from the group consisting of titanium metal, titanium alloy, titanium nitride, tantalum metal, tantalum alloy, or tantalum nitride;   a conductive layer over and in direct contact with said separation layer, said conductive layer comprising the chemical element copper, wherein the conductive layer comprises more than 50% atomic percentage of copper; and   a patterned mask layer disposed over and in direct contact with the conductive layer, wherein the patterned mask layer comprises a first width along a first direction, wherein the conductive layer, the separation layer, and the barrier layer comprise a second width along the first direction, and wherein the second width is smaller than the first width.   
     
     
         9 . The device of  claim 8 , wherein said barrier layer comprises titanium-tungsten alloy. 
     
     
         10 . The device of  claim 8 , wherein the chemical element copper is in the form of at least one of copper metal or copper alloy. 
     
     
         11 . The device of  claim 8 , wherein said separation layer comprises at least one of titanium metal, titanium alloy, tantalum metal or tantalum alloy. 
     
     
         12 . The device of  claim 8 , wherein said separation layer comprises at least one of titanium metal or titanium alloy.