Semiconductor device with carbon atoms implanted under gate structure

Abstract

An exemplary semiconductor device includes a substrate, a spacer, a metal silicide layer and carbon atoms. The substrate has a gate structure formed thereon. The spacer is formed on the sidewall of the gate structure. The spacer has a first side adjacent to the gate structure and a second side away from the gate structure. The metal silicide layer is formed on the substrate and adjacent to the second side of the spacer but away from the first side of the spacer. The carbon atoms are formed into the substrate and adjacent to the first side of the spacer but away from the second side of the spacer.

1 . A semiconductor device comprising:
 a substrate with a gate structure formed thereon;   a spacer formed on the sidewall of the gate structure, wherein the spacer has a first side adjacent to the gate structure and a second side away from the gate structure;   a metal silicide layer formed on the substrate and adjacent to the second side of the spacer but away from the first side of the spacer; and   carbon atoms in the substrate and adjacent to the first side of the spacer but away from the second side of the spacer.   
     
     
         2 . The semiconductor device of  claim 1 , wherein the gate structure comprises a gate dielectric layer and a gate stacked on the substrate in that order. 
     
     
         3 . The semiconductor device of  claim 1 , wherein the distribution of the carbon atoms defines a region under a corner of the gate structure. 
     
     
         4 . The semiconductor device of  claim 1 , further comprising:
 a source/drain region formed in the substrate and under the metal silicide layer.   
     
     
         5 . The semiconductor device of  claim 1 , further comprising:
 a source/drain extension region formed in the substrate and under the spacer.   
     
     
         6 . A semiconductor device comprising:
 a substrate having a gate structure formed thereon;   a source/drain region formed in the substrate;   a metal silicide layer formed on the substrate and above the source/drain region;   a source/drain extension region formed in the substrate and connected with the end of the source/drain region adjacent to the gate structure; and   carbon atoms formed into the substrate and spaced from the metal silicide layer by the source/drain extension region.   
     
     
         7 . The semiconductor device of  claim 6 , further comprising:
 a spacer formed on the sidewall of the gate structure and overlying the source/drain extension region.   
     
     
         8 . The semiconductor device of  claim 6 , wherein the gate structure comprises a gate dielectric layer and a gate stacked on the substrate in that order. 
     
     
         9 . The semiconductor device of  claim 6 , wherein the distribution of the carbon atoms defines a region under a corner of the gate structure.