Semiconductor device including air gaps and method of fabricating the same

Abstract

This technology provides a semiconductor device and a method of fabricating the same, which may reduce parasitic capacitance between adjacent conductive structures, The method of fabricating a semiconductor device may include forming a plurality of bit line structures over a substrate, forming contact holes between the bit line structures, forming sacrificial spacers over sidewalis of the contact holes, forming first plugs recessed into the respective contact holes, forming air gaps by removing the sacrificial spacers, forming capping structures capping the air gaps while exposing top surfaces of the first plugs, and forming second plugs over the first plugs.

1 - 14 . (canceled) 
     
     
         15 . A semiconductor device comprising:
 a plurality of bit line structures formed over a substrate;   storage node contact holes formed to have sidewalls of the bit line structures exposed therethrough;   silicon plugs recessed and formed in the respective storage node contact holes;   air gaps formed between the sidewalls of the bit line structures and the silicon plugs;   capping layer patterns formed over the air gaps;   passivation layers formed over the respective capping layer patterns; and   metal plugs formed over the respective silicon plugs,   wherein the air gaps are capped with the respective capping layer patterns and passivation layers.   
     
     
         16 . The semiconductor device of  claim 15 , wherein the capping layer patterns comprise oxide of the silicon plugs. 
     
     
         17 . The semiconductor device of  claim 15 , wherein the passivation layers are formed of a spacer type, which covers upper sides and sidewalls of the storage node contact holes. 
     
     
         18 . The semiconductor device of  claim 15 , wherein the passivation layers comprise silicon nitride. 
     
     
         19 . The semiconductor device of  claim 15 , wherein:
 each silicon plug comprises a polysilicon layer, and   each metal plug comprises a tungsten layer.   
     
     
         20 . The semiconductor device of  claim 15 , further comprising:
 metal silicide formed between the silicon plugs and the metal plugs.