Method and apparatus of forming a sputtered doped seed layer

Abstract

The present invention generally provides a method and apparatus for forming a doped layer on a substrate to improve uniformity of subsequent deposition thereover. Preferably, the layer is deposited by a sputtering process, such as physical vapor deposition (PVD) or Ionized Metal Plasma (IMP) PVD, using a doped target of conductive material. Preferably, the conductive material, such as copper, is alloyed with a dopant, such as phosphorus, boron, indium, tin, beryllium, or combinations thereof, to improve deposition uniformity of the doped layer over the substrate surface and to reduce oxidation of the conductive material. It is believed that the addition of a dopant, such as phosphorus, stabilizes the conductive material surface, such as a copper surface, and lessens the surface diffusivity of the conductive material. The overall surface diffusivity of copper is reduced such that the tendency to agglomerate or to become discontinuous is reduced, thereby allowing the deposition of a smoother conductive film and thereby reducing localized agglomeration of the conductive material. The smoother film is highly desirable for subsequent deposition processes. A conductive material, such as copper, can be deposited on the deposited doped layer by a variety of processes including PVD, chemical vapor deposition (CVD), electroplating, electroless deposition and other deposition processes.

1 . A method for forming a conductive feature, comprising: 
 a) sputtering material from a target comprising copper and phosphorus;    b) ionizing the sputtered material;    c) depositing a seed layer comprising copper and phosphorous over a surface of a substrate.    
     
     
         2 . The method of  claim 1 , further comprising depositing a copper layer on at least a portion of the seed layer on the substrate by physical vapor deposition, ionized metal plasma deposition, chemical vapor deposition, electroplating, electroless deposition, or evaporation.  
     
     
         3 . The method of  claim 1 , further comprising depositing copper on at least a portion of the seed layer by an electroplating process.  
     
     
         4 . The method of  claim 1 , wherein the target further comprises tungsten, aluminum, or a combination thereof.  
     
     
         5 . The method of  claim 1 , further comprising sputtering material from a doped coil comprising: 
 a) copper, tungsten, aluminum or combinations thereof; and    b) a doping material selected from the group of phosphorus, boron, indium, tin, beryllium or combinations thereof.    
     
     
         6 . The method of  claim 5 , wherein the doped coil comprises copper and phosphorous.  
     
     
         7 . The method of  claim 1 , wherein the sputtered material comprises about 0.01% to about 15% by weight of phosphorous.  
     
     
         8 . The method of  claim 1 , wherein the seed layer comprises about 0.01% to about 15% by weight of phosphorous.  
     
     
         9 . A method for forming a conductive feature, comprising: 
 a) positioning a substrate to have the feature formed thereon within a processing chamber, wherein the processing chamber includes a target comprising copper and phosphorus;    b) sputtering material from the target;    c) ionizing the sputtered material;    d) depositing a seed layer comprising copper and phosphorous over a surface of the substrate; and    e) depositing a copper layer on at least a portion of the seed layer.    
     
     
         10 . The method of  claim 9 , wherein the sputtered material comprises about 0.01% to about 15% by weight of phosphorous.  
     
     
         11 . The method of  claim 9 , wherein the copper layer is deposited by physical vapor deposition, ionized metal plasma deposition, chemical vapor deposition, electroplating, electroless deposition, or evaporation.  
     
     
         12 . The method of  claim 9 , wherein the copper layer is deposited by an electroplating process.  
     
     
         13 . The method of  claim 9 , further comprising sputtering material from a doped coil comprising: 
 a) copper, tungsten, aluminum or combinations thereof; and    b) a doping material selected from the group of phosphorus, boron, indium, tin, beryllium or combinations thereof.    
     
     
         14 . The method of  claim 13 , wherein the doped coil comprises copper and phosphorous.  
     
     
         15 . The method of  claim 9 , further comprising depositing a refractory metal liner layer prior to depositing the seed layer.  
     
     
         16 . The method of  claim 15 , wherein the refractory metal liner layer comprises one or more materials selected from the group consisting of tantalum, tantalum nitride, titanium, titanium nitride, tungsten, and tungsten nitride.  
     
     
         17 . The method of  claim 9 , wherein the target further comprises tungsten, aluminum, or a combination thereof.  
     
     
         18 . The method of  claim 9 , wherein the seed layer further comprises tungsten, aluminum, or a combination thereof.  
     
     
         19 . A method for facilitating deposition of an electrochemical copper bulk layer onto a semiconductor substrate, comprising: 
 a) positioning a semiconductor substrate to be processed within a processing chamber, wherein the processing chamber includes a target comprising copper and phosphorus;    b) sputtering material from the target;    c) ionizing the sputtered material;    d) depositing a seed layer comprising copper and phosphorous over a surface of a substrate; and    e) depositing a copper layer on at least a portion of the seed layer.    
     
     
         20 . The method of  claim 19 , wherein the sputtered material comprises about 0.01% to about 15% by weight of phosphorous.  
     
     
         21 . The method of  claim 19 , further comprising depositing a refractory metal liner layer prior to depositing the seed layer.  
     
     
         22 . The method of  claim 21 , wherein the refractory metal liner layer comprises one or more materials selected from the group consisting of tantalum, tantalum nitride, titanium, titanium nitride, tungsten, and tungsten nitride.  
     
     
         23 . The method of  claim 19 , wherein the target further comprises tungsten, aluminum, or a combination thereof.  
     
     
         24 . The method of  claim 19 , wherein the seed layer further comprises tungsten, aluminum, or a combination thereof.  
     
     
         25 . The method of  claim 19 , wherein the seed layer comprises about 0.01% to about 15% by weight of phosphorous.