Taiwan Semiconductor Manufacturing Comp. Ltd.

Chi-Ping Chen

Chen-Peng Fan

Ming-Shuo Yen

Fang-Jen Hsu

A method for etching access opening to aluminum alloy wire bonding pads of integrated circuit chips is described wherein a polymer layer is in-situ deposited into the opening after the bonding pad has been exposed by dry etching of a passivation layer. The passivation layer, is first etched with fluorocarbon etchants and then a TiN ARC layer is removed from over the aluminum bonding pad with etchants which may contain chlorine either as etch components or as a contaminant in an etchant such as SF.sub.6 non-volatile chlorine containing residues including AlCl.sub.3 and trapped Cl.sub.2, are left behind after the ARC layer has been removed. These cause corrosion of the bonding pad when exposed to atmospheric moisture. The polymer layer deposited immediately after the pad surface is exposed by the etchant, provides a temporary seal over the aluminum bonding pad, protecting it from exposure to moisture during subsequent processing steps.

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Hsin-chu, Taiwan

Chi-Ping Chen