Patent ID: 6787461
Filing Date: 2004-09-07
Classification: H01L

Abstract:
A method for forming a plug tungsten layer, the method comprising:providing a semiconductor substrate; forming a dielectric layer on said semiconductor substrate; forming a photoresist layer on said dielectric layer; etching said dielectric layer byway of using said photoresist layer as an etching mask to form a via hole in said dielectric layer; removing said photoresist layer; conforming a titanium layer on said dielectric layer and the sidewall and the bottom of said via hole; forming a first nitride titanium layer on said titanium layer by way of using a metal organic chemical vapor deposition; forming a second nitride titanium layer on said first nitride titanium layer by way of using a physical vapor deposition wherein said titanium layer, said first nitride titanium layer and said second nitride titanium layer stack to form a barrier layer; treating said barrier layer by way of using a plasma process with nitrogen/hydrogen; transporting a mixing gas having a hydrogen and a silane on said barrier layer to absorb said mixing gas on said barrier layer; performing a purge/vacuum process to remove remainder after absorption; transporting a reactive gas with a WF6 on said barrier layer with said mixing gas to perform a substitution reaction that reacts said reactive gas with said mixing gas, so as to form a continuous tungsten seed layer with a thickness about 20 to 40 Ã¥ on said barrier layer; forming a nucleation layer on said continuous tungsten seed layer; performing a chemical vapor deposition to form a tungsten layer on said continuous tungsten seed layer; and etching back tungsten layer to form said plug tungsten layer in said via hole.