| 摘要 |
PURPOSE: A via formation method using dual damascene processing is provided to reduce the resistance of via by removing metallic polymers using diluted nitric acid. CONSTITUTION: A first metal wire including an aluminum film(35a) and an anti-reflective layer(35b) is formed on a semiconductor substrate(31) having a transistor. An IMD(InterMetal Dielectric)(36) and an etch stopper(37) are sequentially formed on the first metal wire. A via hole is formed to expose the first metal wire by selectively etching the etch stopper(37) and the IMD(36). Metallic polymers generated in the via hole are removed by using diluted nitric acid. A trench is formed at upper part of the via hole. Then, a second metal wire is filled into the via hole and the trench.
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