Phosphorus doped copper

Abstract

The present invention generally provides a method and an apparatus for forming a doped metal film on a conductive substrate. In one aspect of the invention, the deposition process comprises first depositing a phosphorus doped seed layer on a conductive substrate, and then depositing a conductive metal layer on the phosphorus doped seed layer to form a conductive film. In another aspect, the invention provides a method of processing a substrate including depositing a dielectric layer on a substrate, etching a feature into the substrate, depositing a conductive layer in the feature, depositing a phosphorus doped seed layer on the conductive barrier layer, and depositing a conductive metal layer on the phosphorus doped seed layer. In another aspect of the invention, an apparatus is provided that includes a phosphorus doped anode used for depositing a phosphorus doped metal film, such as a seed layer, in an electrochemical deposition process. The phosphorus doped anode preferably includes an enclosure providing for flow of an electrolyte therethrough, a phosphorus doped metal disposed within the enclosure, and an electrode disposed through the enclosure and in electrical connection with the phosphorus doped metal. Another aspect of the invention provides an apparatus for electrochemical deposition of a phosphorus doped metal onto a substrate includes a substrate holder adapted to hold the substrate in a position where the substrate plating surface is exposed to an electrolyte in an electrolyte container, a cathode electrically contacting the substrate plating surface, an electrolyte container having an electrolyte inlet, an electrolyte outlet and an opening adapted to receive the substrate plating surface, and a phosphorus doped anode electrically connected to the electrolyte.

1 . A method of depositing a conductive film on a conductive substrate, comprising: 
 depositing a phosphorus containing layer on the conductive substrate; and    depositing a conductive metal layer on the phosphorus containing layer to form the conductive film.    
     
     
         2 . The method of  claim 1 , wherein the phosphorus containing layer comprises a phosphorus doped seed layer.  
     
     
         3 . The method of  claim 2 , wherein the phosphorus doped seed layer comprises phosphorus doped copper.  
     
     
         4 . The method of  claim 2 , wherein the phosphorus doped seed layer comprises between about 0.01% and about 15% of phosphorus by weight.  
     
     
         5 . The method of  claim 1 , wherein the conductive metal layer comprises copper.  
     
     
         6 . The method of  claim 2 , wherein the phosphorus doped seed layer is deposited by an electrochemical deposition technique.  
     
     
         7 . The method of  claim 6 , wherein the conductive metal layer is deposited by an electrochemical deposition technique.  
     
     
         8 . A method of processing a substrate, comprising: 
 depositing a dielectric layer on the substrate;    etching a feature in the dielectric layer;    depositing a conductive layer in the feature;    depositing a phosphorus doped seed layer on the conductive layer; and    depositing a conductive metal layer on the phosphorus doped seed layer.    
     
     
         9 . The method of  claim 8 , wherein the conductive layer is a barrier or liner layer comprising a conductive material selected from the group consisting of Ti, TiN, Ta, TaN x , W, WN x , and combinations thereof.  
     
     
         10 . The method of  claim 8 , wherein the phosphorus doped seed layer comprises phosphorus doped copper.  
     
     
         11 . The method of  claim 10 , wherein the phosphorus doped seed layer further comprises a dopant material selected from the group of boron, indium, tin, beryllium, and combinations thereof.  
     
     
         12 . The method of  claim 10 , wherein the phosphorus doped seed layer comprises between about 0.01% and about 15% phosphorus by weight.  
     
     
         13 . The method of  claim 10 , wherein the phosphorus doped seed layer is deposited by an electrochemical deposition technique.  
     
     
         14 . The method of  claim 8 , wherein the conductive metal layer comprises copper.  
     
     
         15 . The method of  claim 8 , wherein the conductive metal layer is electrochemically deposited.