Method for forming a TiN layer on top of a metal silicide layer in a semiconductor structure and structure formed

A method for forming a TiN layer on top of a metal silicide layer in a semiconductor structure without the formation of a thick amorphous layer containing Ti, Co and Si and the structure formed are provided. In the method, after a Ti layer is deposited on top of a metal silidide layer, a dual-step annealing process is conducted in which a low temperature annealing in a forming gas (or ammonia) at a temperature not higher than 500° C. is first conducted for less than 2 hours followed by a high temperature annealing in a nitrogen-containing gas (or ammonia) at a second temperature not lower than 500° for less than 2 hours to form the TiN layer. The present invention method prevents the problem usually caused by a thick amorphous material layer of Ti-Si-Co which produces weakly bonded Ti which reacts with fluorine atoms from WF6 during a subsequent CVD W deposition process and causes liner failure due to a volume expansion of the amorphous material. The maximum thickness of the amorphous material layer formed by the present invention method is less than 5 nm which minimizes the line failure problem.