CORROSION STUDY OF AN AL-CU ALLOY EXPOSED TO REACTIVE ION ETCHING

The purpose of this work has been to determine relative effects of the very aggressive reactive ion etch (RIE) and post-RIE cleaning steps on the corrosion behavior of the Al-Cu films. The samples were prepared under broadly varied but controlled conditions, in a form amenable to analysis by either electrochemical or temperature/humidity (T/H) tests coupled with resistance measurements. Electrochemical data obtained in a droplet of triple-distilled water are correlated with the residual surface impurities evaluated by Auger electron spectroscopy (AES) and, in parallel, ion chromatography (IC), and inductively coupled plasma (ICP). The results provide clear information about the material-process interaction and allow selection of the most effective process sequence to minimize corrosion risks.