Immersion bias for use in electro-chemical plating system

Abstract

A method for immersing a substrate into a processing solution. The method includes connecting a power supply between a conductive layer on the substrate and an electrode positioned in the processing solution, immersing the substrate into the processing solution, and applying an electrical bias to the conductive layer during the immersion.

1 . A method for immersing a substrate into a processing solution, comprising: 
 connecting a power supply between a conductive layer on the substrate and an electrode positioned in the processing solution;    immersing the substrate into the processing solution; and    applying a forward electrical bias to the conductive layer during the immersion.    
     
     
         2 . The method of  claim 1 , wherein the forward bias is a plating bias configured to deposit metal ions in the processing solution onto the conductive layer.  
     
     
         3 . The method of  claim 2 , wherein the forward bias is a low plating bias.  
     
     
         4 . The method of  claim 3 , wherein the processing solution is an electrochemical plating solution.  
     
     
         5 . The method of  claim 4 , wherein the conductive layer is a seed layer.  
     
     
         6 . The method of  claim 5 , wherein immersing further comprises rotating the substrate.  
     
     
         7 . The method of  claim 5 , wherein immersing further comprises tilting the substrate.  
     
     
         8 . The method of  claim 1 , wherein applying the electrical bias comprises applying a plating bias to the conductive layer sufficient to overcome etching of the conductive layer by the processing solution.  
     
     
         9 . The method of  claim 1 , wherein the electrical bias is configured such that the conductive layer is at a lower electrical potential than the anode.  
     
     
         10 . The method of  claim 1 , comprising continuing the application of the electrical bias until a forward plating bias is applied to the conductive layer.  
     
     
         11 . A method for immersing a substrate into an electrochemical plating solution, comprising: 
 electrically connecting a seed layer on the substrate with a first terminal of a power supply;    electrically connecting an anode positioned in the electrochemical plating solution to a second terminal of a power supply;    immersing the substrate into the electrochemical plating solution; and    applying an electrical bias between the first terminal and second terminal during the immersing.    
     
     
         12 . The method of  claim 11 , wherein the electrical bias is a low plating voltage.  
     
     
         13 . The method of  claim 11 , wherein the electrical bias is configured such that the first terminal has a lower electrical potential than the second terminal.  
     
     
         14 . The method of  claim 11 , further comprising rotating the substrate during the immersion.  
     
     
         15 . The method of  claim 11 , further comprising tilting the substrate during the immersion.  
     
     
         16 . The method of  claim 11 , further comprising rotating and tilting the substrate during the immersion.  
     
     
         17 . The method of  claim 11 , wherein the electrical bias is a forward bias configured to prevent etching of the seed layer by the electrochemical plating solution.  
     
     
         18 . The method of  claim 1   1 , wherein the electrolyte solution has a pH of less than about 5.  
     
     
         19 . The method of  claim 11 , comprising continuing the application of the electrical bias after the immersion until a plating bias is applied.  
     
     
         20 . A method for immersing a substrate into an electrochemical plating cell, comprising: 
 securing the substrate to an electrical contact element;    rotating the substrate;    immersing the substrate into a plating solution contained in the electrochemical plating cell;    applying an immersion bias to the substrate during the immersing;    applying a plating bias after the substrate is immersed in the plating solution.    
     
     
         21 . The method of  claim 20 , comprising tilting the substrate during the immersion process.  
     
     
         22 . The method of  claim 21 , comprising positioning the substrate horizontally before increasing the immersion bias to the plating bias.  
     
     
         23 . The method of  claim 20 , wherein the immersion bias is a forward bias.  
     
     
         24 . The method of  claim 23 , wherein the forward bias is a low plating bias.  
     
     
         25 . The method of  claim 20 , comprising continuing the immersion bias until the plating bias is applied.