Oxygen in titanium nitride diffusion barriers

Oxygen has been found to play a dominant role in TiN barrier performance between Si(100) and Al. When TiN is exposed to air prior to Al deposition, interdiffusion of the Si/TiN/Al structure is not observed until heating to a temperature of 560 °C, whereas the barrier fails already below 400 °C when Al is deposited in situ onto TiN.