Contact structures in semiconductor devices

Abstract

A semiconductor device with different configurations of contact structures and a method of fabricating the same are disclosed. The semiconductor device includes a substrate, a fin structure disposed on the substrate, a gate structure disposed on the fin structure, a source/drain (S/D) region disposed adjacent to the gate structure, a contact structure disposed on the S/D region, and a dipole layer disposed at an interface between the ternary compound layer and the S/D region. The contact structure includes a ternary compound layer disposed on the S/D region, a work function metal (WFM) silicide layer disposed on the ternary compound layer, and a contact plug disposed on the WFM silicide layer.

What is claimed is: 
     
         1 . A semiconductor device, comprising:
 a gate structure disposed on first and second fin structures;   a merged source/drain (S/D) region disposed on the first and second fin structures; and   a contact structure disposed on the merged S/D region,   wherein the contact structure comprises ternary compound clusters disposed on the merged S/D region, a work function metal (WFM) silicide layer disposed on the ternary compound clusters and the merged S/D region, and a contact plug disposed on the WFM silicide layer.   
     
     
         2 . The semiconductor device of  claim 1 , wherein the ternary compound clusters comprise a zirconium-based ternary compound. 
     
     
         3 . The semiconductor device of  claim 1 , wherein the ternary compound clusters comprise faceted surfaces. 
     
     
         4 . The semiconductor device of  claim 1 , wherein the ternary compound clusters are separated from each other by interfaces between the WFM silicide layer and the S/D region. 
     
     
         5 . The semiconductor device of  claim 1 , further comprising a dipole layer disposed at interfaces between the WFM silicide layer and the S/D region. 
     
     
         6 . The semiconductor device of  claim 1 , further comprising a dipole layer disposed at interfaces between the ternary compound clusters and the S/D region. 
     
     
         7 . A method, comprising:
 forming a fin structure on a substrate;   forming a source/drain (S/D) region on the fin structure;   forming a contact opening on the S/D region;   forming a doped work function metal (WFM) silicide layer within the contact opening;   forming a ternary compound layer between the doped WFM silicide layer and the S/D region; and   forming a contact plug within the contact opening.   
     
     
         8 . The method of  claim 7 , wherein forming the doped WFM silicide layer comprises depositing a dopant source layer on the S/D region, and
 wherein the dopant source layer comprises a metal with an electronegativity value smaller than an electronegativity value of a metal in a metal silicide of the doped WFM silicide layer.   
     
     
         9 . The method of  claim 7 , wherein forming the ternary compound layer comprises:
 depositing a zirconium-based dopant source layer on the S/D region;   depositing a WFM layer on the zirconium-based dopant source layer; and   performing an annealing process.   
     
     
         10 . The method of  claim 7 , wherein forming the ternary compound layer comprises forming a zirconium-based ternary compound layer. 
     
     
         11 . The method of  claim 7 , wherein forming the ternary compound layer comprises forming the ternary compound layer with faceted surfaces facing the doped WFM silicide layer. 
     
     
         12 . The method of  claim 7 , further comprising performing an annealing process after forming the doped WFM silicide layer. 
     
     
         13 . The method of  claim 7 , further comprising depositing a nitride capping layer on the doped WFM silicide layer. 
     
     
         14 . A method, comprising:
 forming a gate structure disposed on a substrate;   forming a source/drain (S/D) region on the substrate; and   forming a contact structure on the S/D region, wherein forming the contact structure comprises:
 depositing a dopant source layer on the S/D region; 
 depositing a metal layer on the dopant source layer; and 
 depositing a contact plug on the metal layer. 
   
     
     
         15 . The method of  claim 14 , wherein depositing the dopant source layer comprises depositing a transition metal layer with an electronegativity value smaller than an electronegativity value of the metal layer. 
     
     
         16 . The method of  claim 14 , wherein depositing the dopant source layer comprises depositing a zirconium-based transition metal layer. 
     
     
         17 . The method of  claim 14 , further comprises performing an annealing process to form a ternary compound layer directly on the S/D region. 
     
     
         18 . The method of  claim 14 , further comprising depositing a barrier layer on the S/D region prior to depositing the dopant source layer. 
     
     
         19 . The method of  claim 14 , further comprising depositing a nitride layer on the metal layer prior to depositing the contact plug. 
     
     
         20 . The method of  claim 14 , further comprising:
 depositing an other metal layer on the metal layer prior to depositing the contact plug; and   performing a nitridation process on the another metal layer.