摘要 |
The present invention provides a method of forming a metal stack structure over a substrate of a semiconductor device, comprising: (a) forming a first metal layer over the substrate, (b) forming a tungsten silicide nitride layer over the first metal layer, (c) forming a second metal layer over the tungsten silicide nitride layer, and (d) annealing the metal stack structure at a diffusion temperature. The tungsten silicide nitride layer inhibits diffusion of the metal in the metal stack. In one embodiment, the annealing is performed in the presence of a forming gas mixture comprising deuterium. In one particularly advantageous embodiment, the metal stack is formed in a contact opening or via. In yet other embodiments, the first metal layer may be a stack layer of titanium and titanium nitride and the second metal layer may be aluminum or copper.
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