Titanium Nitride Formation on Semiconductor Wafers by Reaction of Titanium and Nitrogen-Containing Gases in Integrated Process Systems

摘要

The present invention comprises the steps of (a) forming a titanium layer on a semiconductor wafer without oxygen-containing gas in a vacuum deposition chamber; (b) moving the titanium coated wafer into a closed annealing chamber without exposing the newly formed titanium layer to an oxygenous gas; (c) annealing the titanium-coated semiconductor wafer in an oxygen-free nitrogen-containing atmosphere at an annealing temperature of 400 to 650 ° C. in a sealed annealing chamber to form a titanium nitride compound on the wafer; And (d) further annealing the wafer at a temperature of about 800 to 900 ° C. to form a stoichiometrically stable titanium nitride (TiN) phase on the wafer. It starts. The resulting titanium nitride layer can be patterned to form partial interconnects on the wafer and provide a barrier between the metal contact such as aluminum and the underlying titanium silicide. According to a preferred embodiment, the initial annealing temperature is in the range of about 400 to 600 ° C. such that all titanium reacts with nitrogen to form a titanium nitride compound on the wafer.