Semiconductor device and process for forming amorphous titanium silicon nitride on substrate

Abstract

A semiconductor device comprising a substrate, a conductor and an insulating film provided on the surface of the substrate, part of the surface of the substrate being electrically connected with the conductor through a contact hole made in the insulating film, wherein a barrier layer present between part of the surface of the substrate and the conductor is provided only on the bottom of the contact hole, and the barrier layer provided on the bottom comprises amorphous titanium silicon nitride. This can provide a structure that has a barrier layer with a low contact resistance, enables formation of a conductor film of good quality on the barrier layer, and can attain a good electrical conduction even at fine contact holes.

What is claimed is:  
     
         1 . A semiconductor device comprising a substrate, a conductor and an insulating film provided on the surface of the substrate, part of the surface of the substrate being electrically connected with the conductor through a contact hole made in the insulating film, wherein; 
 a barrier layer present between part of the surface of the substrate and the conductor is provided only at the bottom of the contact hole; and    the barrier layer provided at the bottom comprises amorphous titanium silicon nitride.    
     
     
         2 . The semiconductor device according to    claim 1   , wherein a titanium silicide layer is provided between the substrate surface and the barrier layer.  
     
     
         3 . The semiconductor device according to    claim 1   , wherein the conductor has a conductive plug provided on the barrier layer and present in the contact hole and a conductive layer present on the conductive plug and on the insulating film.  
     
     
         4 . The semiconductor device according to    claim 3   , wherein a layer of a material different from both the materials for the conductive plug and conductive layer is provided between the conductive plug and the conductive layer.  
     
     
         5 . The semiconductor device according to    claim 1   , wherein part of the substrate surface corresponds to part of the surface of a source or drain region of a transistor, and a titanium silicide layer is provided on the uncovered surface of the source or drain region.  
     
     
         6 . The semiconductor device according to    claim 1   , wherein the contact hole has a side length smaller than 0.25 μm.  
     
     
         7 . The semiconductor device according to    claim 3   , wherein the conductive plug is made of an aluminum metal, a tungsten metal or a copper metal.  
     
     
         8 . The semiconductor device according to    claim 3   , wherein the conductive plug comes in contact with the sidewall of the contact hole.  
     
     
         9 . The semiconductor device according to    claim 1   , wherein the insulating film contains nitrogen in its surface portion.  
     
     
         10 . The semiconductor device according to    claim 1   , wherein the amorphous titanium silicon nitride is in a thickness of 10 nm or less.  
     
     
         11 . A process for forming amorphous titanium silicon nitride on the surface of a substrate, comprising the steps of: 
 a) forming titanium silicide on the surface of the substrate; and    b) exposing the titanium silicide formed on the surface of the substrate, to nitrogen plasma while maintaining the temperature of the substrate within the range of from 200° C. to 450° C. and keeping the inside of a reaction chamber at a pressure of 13.3 Pa or above, to form the amorphous titanium silicon nitride.    
     
     
         12 . The process according to    claim 11   , wherein an insulating film having a contact hole is formed on the titanium silicide after the titanium sulicide has been formed, and the amorphous titanium silicon nitride is formed on the surface of the titanium silicide laid bare at the contact hole.  
     
     
         13 . The process according to    claim 12   , which further comprises the step of selectively depositing in the contact hole a conductor different from the titanium silicon nitride.  
     
     
         14 . The process according to    claim 13   , wherein the conductor is formed by chemical vapor deposition making use of an alkyl aluminum hydride as a material gas.  
     
     
         15 . The process according to    claim 11   , wherein before the titanium silicide is exposed to nitrogen plasma, the surface of the titanium silicide is cleaned.  
     
     
         16 . A process for forming amorphous titanium silicon nitride on the surface of a substrate provided in a reaction chamber, comprising the step of introducing a tetradiethylaminotitanium gas and an Si 2 H 6  gas into the reaction chamber while maintaining the substrate temperature within the range of from 200° C. to 450° C. and keeping the inside of the reaction chamber at a pressure of from 13.3 Pa to 267 Pa, to form the amorphous titanium silicon nitride on the substrate.  
     
     
         17 . The process according to    claim 16   , wherein the substrate temperature is set within the range of from 300° C. to 400° C.  
     
     
         18 . The process according to    claim 16   , wherein ammonia gas is introduced into the reaction chamber.  
     
     
         19 . The process according to    claim 16   , wherein a metal film containing aluminum is formed after the amorphous titanium silicon nitride has been formed.  
     
     
         20 . A process for producing the semiconductor device according to    claim 1   , comprising the step of exposing titanium silicide to nitrogen plasma or to a gas of tetradiethylaminotitanium.