Selective W CVD plug process with a RTA self-aligned W-silicide barrier layer

摘要

The present invention provides a method of fabricating a tungsten (W) plug 36 contact to a substrate using a selective W CVD Process with a self-aligned W-Silicide Barrier layer 34. The method comprises the steps of: forming first insulating layer 20 over a silicon semiconductor substrate 10; forming a first (contact) opening 24 in the first insulating layer 20 exposing the surface of the substrate; selectively growing a thin first tungsten layer 30 over the exposed substrate surface; rapidly thermally annealing the substrate forming a thin first tungsten silicide layer 34 from the thin first tungsten layer 30; selectively depositing a tungsten plug 36 over the first thin tungsten silicide layer 34 substantially filling the first opening 36 thereby forming a W plug contact. The RTA/W silicide layer 34 lowers the contact resistance, increases the adhesion and facilitates the selective deposition of the W plug 36.