Semiconductor devices and methods to form a contact in a semiconductor device

Abstract

Semiconductor devices and methods to form a contact of a semiconductor device are disclosed. An example method to form a contact includes forming an insulating layer on a substrate; etching the insulating layer to form a contact hole; depositing a silicon layer on sidewalls and an undersurface of the contact hole; forming a silicon spacer on the sidewalls of the contact hole by etching the silicon layer; transforming the silicon spacer to a silicon nitride spacer; depositing a diffusion barrier on the silicon nitride spacer; and filling the contact hole with tungsten. Because the silicon nitride spacer formed on the sidewalls of the contact hole can serve as a leakage current blocking layer, the yield and the reliability of the semiconductor devices manufactured by this example process are enhanced.

1 . A semiconductor device comprising: 
 a silicon substrate;    an insulating layer formed on the silicon substrate, the insulating layer including a contact hole formed therein;    a silicon nitride spacer for blocking leakage current on sidewalls of the contact hole;    a conductive material diffusion barrier layer on the silicon nitride spacer and an undersurface of the contact hole; and    a conductive metal deposited on the diffusion barrier layer in the contact hole to thereby fill the contact hole.    
   
   
       2 . A semiconductor device as defined in  claim 1 , wherein the silicon nitride spacer is formed by nitrifying a silicon spacer.  
   
   
       3 . A semiconductor device as defined in  claim 2 , wherein the silicon nitride spacer is formed by NH 3  plasma treating a silicon spacer.  
   
   
       4 . A semiconductor device as defined in  claim 2 , wherein the silicon nitride spacer is formed by annealing a silicon spacer through a N 2  or NH 3  gas atmosphere heat treatment.  
   
   
       5 . A semiconductor device as defined in  claim 1 , wherein the conductive material diffusion barrier layer is a CVD TiN layer.  
   
   
       6 . A semiconductor device as defined in  claim 1 , wherein the conductive material diffusion barrier layer has a thickness of at least 25-150 Å.  
   
   
       7 . A semiconductor device as defined in  claim 1 , wherein the silicon nitride spacer has a thickness of about 50-200 Å.  
   
   
       8 . A semiconductor device as defined in  claim 1 , wherein the conductive metal includes tungsten.