Method of enhancing hardness of sputter deposited copper films

Abstract

The present invention provides a method and apparatus for forming a copper layer on a substrate, preferably using a sputtering process. The sputtering process involves bombarding a conductive member of enhanced hardness with ions to dislodge the copper from the conductive member. The hardness of the target may be enhanced by alloying the copper conductive member with another material and/or mechanically working the material of the conductive member during its manufacturing process in order to improve conductive member and film qualities. The copper may be alloyed with magnesium, zinc, aluminum, iron, nickel, silicon and any combination thereof.

1 . A method of depositing a seed layer over a surface of a substrate, comprising: 
 depositing a copper alloy seed layer over a surface of a substrate at a substrate temperature between about −50° C. and about 150° C., the copper alloy seed layer comprising an alloying material selected from the group of aluminum, magnesium, and combinations thereof, the alloying material being present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 10 weight percent.    
     
     
         2 . The method of  claim 1 , wherein the copper alloy seed layer is deposited at a substrate temperature less than about 50° C.  
     
     
         3 . The method of  claim 1 , wherein the copper alloy seed layer is deposited by physical vapor deposition.  
     
     
         4 . The method of  claim 3 , wherein the copper alloy seed layer is deposited by utilizing a high density plasma.  
     
     
         5 . The method of  claim 1 , wherein the alloying material is present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 5 weight percent.  
     
     
         6 . A method of forming a feature, comprising: 
 depositing a barrier layer over a surface of a substrate; and    depositing a copper alloy seed layer over the barrier layer, the copper alloy seed layer comprising an alloying material selected from the group of aluminum, magnesium, and combinations thereof, the alloying material being present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 10 weight percent.    
     
     
         7 . The method of  claim 6 , wherein the barrier layer comprises a material selected from the group consisting of tantalum nitride, tantalum, titanium, titanium nitride, tungsten, tungsten nitride, other refractory metals, other refractory metal nitrides, and combinations thereof.  
     
     
         8 . The method of  claim 6 , further comprising depositing a bulk copper layer over the copper alloy seed layer.  
     
     
         9 . The method of  claim 8 , wherein the bulk copper layer is deposited by electroplating.  
     
     
         10 . The method of  claim 6 , wherein the copper alloy seed layer is deposited at a substrate temperature between about −50° C. and about 150° C.  
     
     
         11 . The method of  claim 10 , wherein the copper alloy seed layer is deposited at a substrate temperature less than about 50° C.  
     
     
         12 . The method of  claim 6 , wherein the alloying material is present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 5 weight percent.  
     
     
         13 . A method of forming a feature, comprising: 
 depositing a barrier layer comprising tantalum nitride;    depositing a copper alloy seed layer over the barrier layer, the copper alloy seed layer comprising aluminum present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 10 weight percent; and    depositing a bulk copper layer over the copper alloy seed layer by electroplating.    
     
     
         14 . The method of  claim 13 , wherein aluminum is present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 5 weight percent.  
     
     
         15 . A structure, comprising: 
 a substrate having a dielectric layer formed thereon, the dielectric layer having an aperture formed therein;    a barrier layer formed over the dielectric layer; and    a copper alloy seed layer formed over the barrier layer, the copper alloy seed layer comprising an alloying material selected from the group of aluminum, magnesium, and combinations thereof, the alloying material being present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 10 weight percent.    
     
     
         16 . The structure of  claim 15 , wherein the alloying material is present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 5 weight percent.  
     
     
         17 . The method of  claim 15 , wherein the barrier layer comprises a material selected from the group consisting of tantalum nitride, tantalum, titanium, titanium nitride, tungsten, tungsten nitride, other refractory metals, other refractory metal nitrides, and combinations thereof.  
     
     
         18 . The structure of  claim 15 , further comprising a bulk copper layer formed over the copper alloy seed layer.  
     
     
         19 . A structure, comprising: 
 a substrate having a dielectric layer formed thereon, the dielectric layer having an aperture formed therein;    a barrier layer comprising tantalum nitride formed over the dielectric layer;    a copper alloy seed layer formed over the barrier layer, the copper alloy seed layer comprising aluminum present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 10 weight percent; and    a bulk copper layer formed over the copper alloy seed layer.    
     
     
         20 . The structure of  claim 19 , wherein aluminum is present in the copper alloy seed layer in a concentration between about 0.01 weight percent and about 5 weight percent.