Diffusion barrier enhancement in metallization structure for semiconductor device fabrication

摘要

The properties of a diffusion barrier material layer (48) over a semiconductor substrate (10) are enhanced in a simple and time-effective manner by immersing the substrate (10) in an oxidizing liquid. For a titanium-tungsten barrier metal (48), a dip in nitric acid for 1-60 minutes provides the metal with an oxide layer (50) of the right thickness of 10-20 ANGSTROM .