Bit line of a semiconductor device and method for fabricating the same

Abstract

A bit line of a semiconductor device includes a first interlayer dielectric film disposed on a semiconductor substrate, a plurality of bit line stacks disposed on the first interlayer dielectric film, a plurality of bit line spacers disposed on side walls of the bit line stacks, and a buffer film disposed on the bit line spacers, the first interlayer dielectric film and the bit line stacks; and a method for fabricating the same.

1 . A bit line of a semiconductor device, comprising: 
 a first interlayer dielectric film disposed on a semiconductor substrate;    a plurality of bit line stacks disposed on the first interlayer dielectric film;    a plurality of bit line spacers disposed on side walls of the bit line stacks; and    a buffer film disposed on the bit line spacers, the first interlayer dielectric film, and the bit line stacks.    
   
   
       2 . The bit line according to  claim 1 , wherein the bit line stacks includes a tungsten film and a hard mask nitride film that are sequentially stacked.  
   
   
       3 . The bit line according to  claim 1 , wherein the bit line spacers include a nitride film.  
   
   
       4 . A method for fabricating a bit line of a semiconductor device, comprising: 
 forming bit line stacks on a first interlayer dielectric film formed on a semiconductor substrate;    forming bit line spacers on side walls of the bit line stacks;    forming a buffer film on the first interlayer dielectric film and bit line stacks;    annealing the buffer film to lower tensile stress thereof; and    forming a second interlayer dielectric film on an entire surface of the resulting structure having the buffer film formed thereon.    
   
   
       5 . The method according to  claim 4 , wherein the bit line stack-forming material includes a tungsten film and a hard mask nitride film sequentially stacked.  
   
   
       6 . The method according to  claim 4 , wherein the bit line spacers include a nitride film.  
   
   
       7 . The method according to  claim 4 , wherein the buffer film includes an oxide film formed via an atomic layer deposition (ALD) process utilizing pyridine as a catalyst.  
   
   
       8 . The method according to  claim 4 , wherein annealing is carried out at a temperature of about 650° C. to 700° C. for about 120 seconds under nitrogen atmosphere.