Prevention of AlCu Line Galvanic Corrosion after Fluoride Containing Stripper Cleaning: A Case Study

Abstract

In this paper, the status of galvanic corrosion on AlCu lines during the AlCu post etch and ashing residue removal process is studied with a fluoride containing stripper in details, including DIW rinse condition and dry process. The experimental data show that galvanic corrosion on AlCu lines is not observed in the chemical cleaning process, but inclined to be caused by the rinse and dry processes in this case. Different scenarios in the rinse process, such as overflow or quick dump rinse (QDR), the times of quick dump rinse cycles, CO2 bubbled DIW and metal protection solution rinse, are studied. At the same time, two kinds of dry processes are also evaluated. The results show the optimized rinse and dry processes can eliminate the galvanic corrosion on AlCu lines without the change of wafer manufacture prevenient process and cleaning solution.