Enhanced barrier liner formation for vias

Abstract

A high integrity, reliable liner is disclosed for a via in which a titanium aluminide layer is preformed as a lining within a via hole prior to deposition of other conductive materials within the via hole. The conductive materials deposited on the preformed titanium aluminide can be either a secondary barrier layer portion of the liner, such as a titanium compound layer, which in turn has a metal plug deposited thereon, or, alternatively, a metal plug directly deposited on the titanium aluminide layer. An important advantage achieved by the present invention is that a via is formed with a substantial elimination of void formation. The enhanced vias are useful in a wide variety of semiconductor devices, including SRAMS and DRAMs.

1 - 40 . (canceled)  
   
   
       41 . A method of forming a semiconductor device, comprising: 
 forming a dielectric layer on an aluminum layer;    forming a via hole through the dielectric layer to expose a surface portion of the aluminum at a bottom of the via hole;    depositing titanium aluminide to form a layer thereof over the exposed surface portion of said aluminum layer, wherein said titanium aluminide layer is formed such that any volume change in said titanium aluminide layer occurs before the forming of any overlying layer; and    depositing a conductive material on the titanium aluminide layer.    
   
   
       42 . The method of  claim 41 , wherein the forming of the titanium aluminide layer comprises sputter depositing the titanium aluminide.  
   
   
       43 . The method of  claim 41 , wherein the depositing of said titanium aluminide further deposits said titanium aluminide on sidewalls of the via hole.  
   
   
       44 . The method of  claim 41 , wherein the depositing of the titanium aluminide comprises depositing TiAl 3 .  
   
   
       45 . The method of  claim 41 , wherein the conductive material comprises a titanium nitride layer, and said method further comprises depositing a refractory metal plug on the conductive material by reduction of a refractory metal halide compound.