| 摘要 |
A structure and method to prevent barrier failure is provided. The present invention replaces a standard titanium-nitride (TiN) barrier metal layer with two separately-formed TiN layers. The two TiN layers provide smaller, mismatched grain boundaries. During subsequent tungsten deposition using WF6, the WF6 finds it difficult to penetrate through the mismatched grain boundaries, thereby minimizing any possibility of "tungsten volcano". One embodiment includes a native or a grown oxide formed between the two TiN layers, thereby providing yet another diffusion barrier to the WF6 and acting as a glue layer between the two TiN layers. The present invention provides a thin and strong barrier metal layer with minimal barrier failures.
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