Method of depositing layers

Abstract

Embodiments disclosed herein generally relate to methods of depositing a plurality of layers. A doped copper seed layer is deposited in a plurality of feature definitions in a device structure. A first copper seed layer is deposited and then the first copper seed layer is doped to form a doped copper seed layer, or a doped copper seed layer is deposited directly. The doped copper seed layer leads to increased flowability, reducing poor step coverage, overhang, and voids in the copper layer.

1 . A method for depositing a plurality of layers, comprising:
 depositing a doped copper seed layer having one or more seed layer portions over a device structure, the doped copper seed layer comprising copper (Cu) and a dopant, the device structure comprising a layer disposed over a substrate, the layer having a surface and a plurality of feature definitions, each of the feature definitions having a plurality of side walls and a bottom, wherein the doped copper seed layer is deposited such that the doped copper seed layer is disposed over the surface, the plurality of side walls and the bottom; and   etching back the doped copper seed layer such that at least one of the one or more seed layer portions is removed.   
     
     
         2 . The method of  claim 1 , wherein the dopant comprises tantalum (Ta), vanadium (V), niobium (Nb), or combinations thereof. 
     
     
         3 . The method of  claim 2 , wherein the depositing the doped copper seed layer is performed by depositing material from a target using a physical vapor deposition process, and the material comprises Cu and at least one of Ta, V, and Nb. 
     
     
         4 . The method of  claim 1 , further comprising:
 depositing a barrier layer on the device structure such that the barrier layer is disposed over the surface, the plurality of side walls and the bottom, the barrier layer comprising a metal;   treating the barrier layer to create a treated barrier layer; and   depositing a liner layer on the treated barrier layer, the liner layer comprising a metal nitride.   
     
     
         5 . The method of  claim 4 , further comprising:
 depositing a second copper layer having one or more copper layer portions over the doped copper seed layer;   etching back the second copper layer such that at least one of the one or more copper layer portions is removed; and   reflowing the doped copper seed layer and the second copper layer to create a combined copper layer.   
     
     
         6 . The method of  claim 5 , wherein the second copper layer has a thickness profile comprising:
 a side wall thickness disposed adjacent to one of the plurality of side walls;   a field thickness disposed over the surface; and   a bottom thickness disposed at the bottom of one of the plurality of feature definitions, wherein the side wall thickness is approximately equal to the field thickness, and the bottom thickness is greater than the side wall thickness.   
     
     
         7 . The method of  claim 5 , wherein
 the treating the barrier layer is performed in a first processing chamber, and   the depositing a doped copper seed layer, the depositing a second copper layer, the etching back the second copper layer and the reflowing the doped copper seed layer and the second copper layer are performed in a second processing chamber.   
     
     
         8 . A method for depositing a plurality of layers, comprising:
 depositing a doped copper seed layer having one or more seed layer portions over a device structure, the doped copper seed layer comprising copper (Cu) and a dopant, the device structure comprising a layer disposed over a substrate, the layer having a surface and a plurality of feature definitions, each of the feature definitions having a plurality of side walls and a bottom; and   etching back the doped copper seed layer such that at least one of the one or more seed layer portions is removed, wherein:
 the doped copper seed layer is disposed over the surface, the plurality of side walls and the bottom, 
 the depositing the doped copper seed layer comprises a physical vapor deposition (PVD) process, and 
 the dopant comprises tantalum (Ta). 
   
     
     
         9 . The method of  claim 8 , wherein the etching back the doped copper seed layer comprises exposing the doped copper seed layer to argon gas (Ar). 
     
     
         10 . The method of  claim 9 , further comprising:
 depositing a barrier layer on the device structure such that the barrier layer is disposed over the surface, the plurality of side walls and the bottom, the barrier layer comprising a metal;   treating the barrier layer to create a treated barrier layer; and   depositing a liner layer on the treated barrier layer, the liner layer comprising a metal nitride.   
     
     
         11 . The method of  claim 10 , further comprising:
 depositing a second copper layer having one or more copper layer portions over the doped copper seed layer;   etching back the second copper layer such that at least one of the one or more copper layer portions is removed; and   reflowing the doped copper seed layer and the second copper layer to create a combined copper layer.   
     
     
         12 . The method of  claim 11 , wherein the second copper layer has a thickness profile comprising:
 a side wall thickness disposed adjacent to one of the plurality of side walls;   a field thickness disposed over the surface; and   a bottom thickness disposed at the bottom of one of the plurality of feature definitions, wherein the side wall thickness is approximately equal to the field thickness, and the bottom thickness is greater than the side wall thickness.   
     
     
         13 . The method of  claim 11 , wherein
 the treating the barrier layer is performed in a first processing chamber, and   the depositing a doped copper seed layer, the depositing a second copper layer, the etching back the second copper layer and the reflowing the doped copper seed layer and the second copper layer are performed in a second processing chamber.   
     
     
         14 . A method for depositing a plurality of layers, comprising
 depositing a doped copper seed layer having one or more seed layer portions over a device structure, wherein the doped copper seed layer comprises a material removed from a target during a physical vapor deposition process (PVD); and   etching back the doped copper seed layer such that at least one of the one or more seed layer portions is removed.   
     
     
         15 . The method of  claim 14 , wherein the device structure comprises a layer disposed over a substrate, the layer having a surface and a plurality of feature definitions, each of the feature definitions having a plurality of side walls and a bottom, and wherein the doped copper seed layer is deposited such that the doped copper seed layer is disposed over the surface, the plurality of side walls and the bottom, and the doped copper seed layer comprises copper (Cu) and a dopant. 
     
     
         16 . The method of  claim 15 , wherein the dopant comprises tantalum (Ta), vanadium (V), niobium (Nb), or combinations thereof. 
     
     
         17 . The method of  claim 14 , wherein the target comprises tantalum (Ta), vanadium (V), niobium (Nb), or combinations thereof. 
     
     
         18 . The method of  claim 15 , further comprising
 depositing a barrier layer on the device structure such that the barrier layer is disposed over the surface, the plurality of side walls and the bottom, the barrier layer comprising a metal;   treating the barrier layer to create a treated barrier layer; and   depositing a liner layer on the treated barrier layer, the liner layer comprising a metal nitride.   
     
     
         19 . The method of  claim 18 , further comprising:
 depositing a second copper layer having one or more copper layer portions over the doped copper seed layer;   etching back the second copper layer such that at least one of the one or more copper layer portions is removed; and   
       reflowing the doped copper seed layer and the second copper layer to create a combined copper layer. 
     
     
         20 . The method of  claim 19 , wherein
 the treating the barrier layer is performed in a first processing chamber, and the depositing a doped copper seed layer, the depositing a second copper layer, the etching back the second copper layer and the reflowing the doped copper seed layer and the second copper layer are performed in a second processing chamber