It was recalled that sputter-deposited N-doped Ti-W alloy was useful as a barrier layer in electroplated Au integrated circuit interconnect structures. However, a persistent problem was the episodic and unexplained appearance of catastrophic barrier failure. It was found that the addition of a small amount of N to the sputtering ambient reduced the problem to a negligible level.

D.R.Evans, D.M.Leet: Journal of the Electrochemical Society, 1994, 141[7], 1867-71