| 摘要 |
PURPOSE:To perform the etching of a metal layer except a pad electrode only by one step by forming a metal layer under a metal bump in a self-aligning manner by an electrolessly plating method. CONSTITUTION:An aluminum pad electrode 3 and an insulating film 4 are formed on an insulating film 2 on a semiconductor substrate 1, and the film on the electrode 3 is removed. The entire surface is coated with a metal layer 5 of Cr or the like, and an aluminum layer 6 is formed on the layer 5. A photosensitive resin film 7 remains on a region to be formed with a metal bump, and the aluminum layer except this region is oxidized to alter it to an aluminum oxide film 8. The film 7 and the film 6 under the film 7 are removed, and a metal layer 9 of Cu or the like is formed by an electrolessly plating method on the layer 5. Then, with the layer 9 as a plating electrode a metal bump 10 is formed of Au, Cu or the like. Thereafter, with the bump 10 as a mask the layer 8 and the layer 5 are removed by etching. Then, after the bump is formed, the etching of the metal layer is performed only by one step to prevent the pad electrode from being damaged due to the etching.
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