Method for fabricating doped polysilicon lines

Abstract

A method of fabricating polysilicon lines and polysilicon gates, the method of including: forming a dielectric layer on a top surface of a substrate; forming a polysilicon layer on a top surface of the dielectric layer; implanting the polysilicon layer with N-dopant species, the N-dopant species essentially contained within the polysilicon layer; implanting the polysilicon layer with a nitrogen containing species, the nitrogen containing species essentially contained within the polysilicon layer.

1 . A method of fabricating a semiconductor structure, comprising: 
 forming a dielectric layer on a top surface of a substrate;    forming a polysilicon layer on a top surface of said dielectric layer;    implanting said polysilicon layer with N-dopant species, said N-dopant species essentially contained within said polysilicon layer;    implanting said polysilicon layer with a nitrogen containing species, said nitrogen containing species essentially contained within said polysilicon layer.    
   
   
       2 . The method of  claim 1 , wherein a peak concentration of said N-dopant species is about equal to a peak concentration of said nitrogen containing species at about a same distance from a top surface of said polysilicon layer.  
   
   
       3 . The method of  claim 1 , wherein a surface concentration of said N-dopant species is about equal to a surface concentration of said nitrogen containing species at about a same distance from a top surface of said polysilicon layer.  
   
   
       4 . The method of  claim 1 , wherein said N-dopant species and said nitrogen containing species have about a same ion implantation concentration profile.  
   
   
       5 . The method of  claim 1 , wherein a surface concentration of said N-dopant species is between about 1E18 atm/cm 3  to about 1E22 atm/cm 3  and a surface concentration of said nitrogen containing species is between about abut 1E18 atm/cm 3  to about 1E21 atm/cm 3 .  
   
   
       6 . The method of  claim 1 , wherein: 
 wherein a peak concentration of said N-dopant species is between about 1E18 atm/cm 3  to about 1E22 atm/cm 3  and a peak concentration of said nitrogen containing species is between about 1E18 atm/cm 3  to about 1E21 atm/cm 3 ; and    said peak concentration of said N-dopant species occurring between a distance of about 0 nm and about ⅓ of a thickness of said polysilicon layer from a top surface of said polysilicon layer and said peak concentration of said nitrogen containing species occurring between about 0 nm to about ⅔ of said thickness of said polysilicon layer from said top surface of said polysilicon layer.    
   
   
       7 . The method of  claim 1 , wherein: 
 said N-dopant species is selected from the group consisting of phosphorus and arsenic; and    said nitrogen containing species is selected from the group consisting of N, N 2 , NO, NF 3 , N 2 O and NH 3 .    
   
   
       8 . The method of  claim 1 , further including: 
 patterning said polysilicon layer into one or more polysilicon lines;    performing a thermal oxidation of sidewalls and top surfaces of said one or more polysilicon lines to form a thermal oxide layer, said thermal oxide layer of about uniform thickness.    
   
   
       9 . The method of  claim 8 , wherein said nitrogen containing species retards oxidation of said one or more polysilicon lines.  
   
   
       10 . The method of  claim 1 , wherein said implanting said polysilicon layer with N-dopant species is performed before said implanting said polysilicon layer with said nitrogen containing species.  
   
   
       11 . The method of  claim 1 , wherein said implanting said polysilicon layer with N-dopant species is performed after said implanting said polysilicon layer with said nitrogen containing species.