Patent ID: 6099701
Filing Date: 2000-08-08
Classification: H01L

Abstract:
A method of fabrication of an Aluminum-alloy line having TiN layers that improve the electromigration resistance of said Aluminum-alloy line; comprising the steps of:a) loading a semiconductor structure into a first sputtering chamber;b) sputtering a first TiN film consisting of three layers over said semiconductor structure; said first TiN film composed of (1) a bottom Ti-rich TiN layer, (2) a middle TiN layer, and (3) a top Ti-rich TiN layer; said top and said bottom Ti-rich TiN layers having a titanium:nitrogen molar ratio of between 1.5:1 to 3:1; wherein sputtering of said first TiN film is comprised of three steps:(1) Step 1--sputtering to form said bottom Ti-rich TiN layer comprising not flowing a N-containing gas;(2) Step 2--sputtering to form said middle TiN layer comprising flowing N-containing gas at a flow rate; and(3) Step 3--sputtering of said top Ti-rich TiN layer comprising not flowing a N-containing gas;c) loading said semiconductor structure into a second sputtering chamber; andd) forming an Aluminum-alloy line over said first TiN film.