| 摘要 |
A method for reworking integrated circuit (IC) wafers having copper-metallized bond pads covered by deposited layers of a barrier metal and a bondable metal. After identifying the wafers with off-spec metal layers, the wafers are chemically etched using selective etchants consecutively until the metal layers over the bond pads are removed without damaging the copper metallization. Replacement metal layers are finally deposited over the bond pads. Specifically, the bondable metal, such as gold, is selectively removed by a cyclic dithio-oxamine compound, dissolved in tetra-hydro-furane or acetone. The barrier metals, such as nickel and palladium, are removed by a mixture of inorganic and organic oxidizing acids.
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