a continuous process for the deposition of robust titanium - containing barrier layers comprises sputtering in a single substrate sputtering chamber a first layer of titanium , sputtering a layer of titanium nitride thereover , treating the titanium nitride layer with a plasma containing oxygen while continuing to sputter the titanium target to deposit a thin layer of tion , and finally sputtering a layer of titanium over the titanium nitride . the latter step removes impurities from the titanium target , preventing poisoning of the target . thus subsequent substrates can be continuously processed in said chamber without degrading the barrier properties or poisoning the titanium target .