| abstract |
A post laser blown fuse slag etch for a copper fuse (30) with a barrier metal liner (18), (e.g., TaxNy, Ta, Ti, TixNy). After the fuse (30) is blown, copper and copper complexes may be selectively removed using a nitric acid and H2O2 solution. Then, a corrosion inhibitor is used to passivate the surface of exposed copper (34). Next, the barrier metal (18) of slag (22) is removed using a strong basic etch chemistry comprising a base plus H2O2. This solution removes the barrier metal selectively with respect to passivation layer (e.g., silicon nitride) (16) and oxides/FSG (12). A diluted HF solution may then be used to remove any trace metal or oxidized copper. |