Electropolishing and chemical mechanical planarization

Abstract

Removing metal from a semiconductor substrate by dissolving ions of the metal into an electrolyte, comprising the steps of: applying a voltage across a polishing pad and the substrate, while an electropolishing electrolyte is dispensed at an interface of the substrate and the polishing pad, and while pooling the electrolyte about the substrate by the polishing pad.

What is claimed is:  
     
         1 . Apparatus for removing metal from a semiconductor substrate, comprising: a polishing pad, a holder of the semiconductor substrate in close proximity to the polishing pad, an electropolishing electrolyte, a dispenser of the electropolishing electrolyte at an interface of the polishing pad and the substrate, and a DC voltage source applying a DC voltage across the polishing pad and the substrate to remove metal from the metal layer.  
     
     
         2 . The apparatus as recited in  claim 1 , wherein the DC voltage source is reversible in polarity.  
     
     
         3 . The apparatus as recited in  claim 1 , wherein the electropolishing electrolyte comprises a polishing composition for polishing the substrate with the polishing pad and with the polishing composition.  
     
     
         4 . A method for removing metal from a semiconductor substrate by dissolving ions of the metal into an electrolyte, comprising the steps of: applying a voltage across a polishing pad and the substrate, while an electropolishing electrolyte is dispensed at an interface of the substrate and the polishing pad, and while pooling the electrolyte about the substrate by the polishing pad.  
     
     
         5 . The method of  claim 4  further comprising the steps of: turning off the voltage across the polishing pad and the substrate, and polishing the substrate with the polishing pad and with the electropolishing electrolyte comprising a polishing composition, while the voltage is turned off.  
     
     
         6 . The method of  claim 4  further comprising the steps of: polishing the substrate with the polishing pad and with the electropolishing electrolyte comprising a polishing composition, while applying the voltage across the polishing pad and the substrate.  
     
     
         7 . The method of  claim 6  further comprising the steps of: turning off the voltage across the polishing pad and the substrate, and polishing the substrate with the polishing pad and with the electropolishing electrolyte comprising a polishing composition, while the voltage is turned off.