Process for rendering metal corrosion-resistant in electrochemical metal deposition

Abstract

A new and improved method for electroplating a metal onto a substrate in such a manner as to render the metal essentially corrosion-resistant during subsequent substrate processing such as chemical mechanical polishing. The process involves incorporating nitrogen into the metal as the metal is electroplated onto the substrate. The process includes preparing the electroplating bath, placing a leveler chemical containing nitrogen in the prepared bath, circulating the leveler chemical throughout the bath and then electroplating the metal on the substrate. In a preferred embodiment, alkyl polyamide, alkyl amine, alkyl amine oxide or thiourea with molecular weight ranging from 100˜1,000,000 is used as the leveler chemical.

1 . A process for electroplating a substrate, comprising the steps of: 
 providing an electrolyte bath comprising a metal;    mixing a nitrogen-containing leveler chemical with said electrolyte bath;    electroplating said metal onto said substrate; and    subjecting said metal to chemical mechanical planarization.    
   
   
       2 . The process of  claim 1  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       3 . The process of  claim 1  wherein said metal comprises copper.  
   
   
       4 . The process of  claim 3  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       5 . The process of  claim 1  wherein said metal is a copper alloy.  
   
   
       6 . The process of  claim 5  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       7 . The process of  claim 1  wherein said metal is a metal selected from the group consisting of copper, aluminum, nickel, chromium, zinc, tin, gold, silver, lead and cadmium.  
   
   
       8 . The process of  claim 7  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       9 . A process for providing a substantially corrosion-resistant metal layer on a substrate, comprising the steps of: 
 providing an electrolyte bath comprising a metal;    mixing a nitrogen-containing leveler chemical with said electrolyte bath; and    incorporating nitrogen from said leveler chemical into said metal and providing said metal on the substrate by electroplating said metal onto the substrate.    
   
   
       10 . The process of  claim 9  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       11 . The process of  claim 9  wherein said metal comprises copper.  
   
   
       12 . The process of  claim 11  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       13 . The process of  claim 9  wherein said metal is a copper alloy.  
   
   
       14 . The process of  claim 13  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea, having a molecular weight ranging from 100˜1,000,000.  
   
   
       15 . The process of  claim 9  wherein said nitrogen is present in said metal in a concentration of from about 10 ppm to about 1000 ppm.  
   
   
       16 . The process of  claim 15  wherein said metal is a metal selected from the group consisting of copper, aluminum, nickel, chromium, zinc, tin, gold, silver, lead and cadmium.  
   
   
       17 . A process for providing a substantially corrosion-resistant metal layer on a substrate, comprising the steps of: 
 providing an electrolyte bath comprising a metal;    mixing a nitrogen-containing leveler chemical with said electrolyte bath; and    incorporating nitrogen from said leveler chemical into said metal at a nitrogen concentration of from about 10 ppm to about 1000 ppm and providing said metal on the substrate by electroplating said metal onto the substrate.    
   
   
       18 . The process of  claim 17  wherein said leveler chemical comprises a leveler chemical selected from the group consisting of alkyl polyamide, alkyl amine, alkyl amine oxide and thiourea having a molecular weight ranging from 100˜1,000,000.  
   
   
       19 . The process of  claim 17  wherein said metal is a copper alloy.  
   
   
       20 . The process of  claim 17  wherein said metal is a metal selected from the group consisting of copper, aluminum, nickel, chromium, zinc, tin, gold, silver, lead and cadmium.