Semiconductor integrated circuit device and method for making the same

Abstract

A method for making a semiconductor integrated circuit device comprises the steps of: (a) depositing a first underlying film made of titanium nitride, on an insulating film having a plurality of through-holes; (b) depositing a tungsten film on the first underlying film, and etching the tungsten film back by means of a fluorine-containing plasma thereby leaving the tungsten film only in the connection holes; (c) sputter etching the surface of the first underlying film to remove the fluorine from the surface of the first underlying film; and (d) forming an aluminum film on the first underlying film. The semiconductor integrated circuit device obtained by the method is also described.

What is claimed is:  
     
         1 . A method of fabricating a semiconductor integrated circuit device, comprising the steps of: 
 (a) forming a first aluminum film over a first insulating film formed over a semiconductor substrate;    (b) forming a first titanium film over said first aluminum film;    (c) forming a first titanium nitride film over said first titanium film;    (d) forming a second insulating film over said first titanium nitride film;    (e) forming first through-holes in said second insulating film, said first through-holes being connected with said first titanium film;    (f) forming a second titanium film over a surface of said first through-holes and said second insulating film;    (g) forming a second titanium nitride film over said second titanium film;    (h) forming a first tungsten film over said second titanium nitride film such that said first through-holes are filled with said first tungsten film;    (i) removing said first tungsten film over said second titanium nitride film such that said first tungsten film formed in said first through-holes is left;    (j) forming a third titanium film over said second titanium film and said first tungsten film formed in said first through-holes; and    (k) forming a second aluminum film over said third titanium film; 
 wherein said step (a) comprises:  
   a first step of depositing a first aluminum by sputtering under conditions that said semiconductor substrate is kept at a first temperature and said first aluminum is deposited at a first deposition rate; and    a second step of depositing a second aluminum by sputtering on said first aluminum under conditions that said semiconductor substrate is kept at a second temperature higher than said first temperature and said second aluminum is deposited at a second deposition rate lower than said first deposition rate, and 
 wherein said step (k) comprises:  
   a first step of depositing a third aluminum by sputtering under conditions that said semiconductor substrate is kept at a third temperature and said third aluminum is deposited at a third deposition rate; and    a second step of depositing a fourth aluminum by sputtering on said third aluminum under conditions that said semiconductor substrate is kept at a fourth temperature higher than said third temperature and said fourth aluminum is deposited at a fourth deposition rate lower than said third deposition rate.    
     
     
         2 . A method of fabricating a semiconductor integrated circuit device according to  claim 1 , wherein each of the first and second aluminum films contains silicon and copper in addition to aluminum.