Electrochemical study of an Al-Cu alloy exposed to reactive ion etching

Electrochemical tests and special samples were used to characterize the corrosion susceptibility of the Al-Cu metallization exposed to reactive ion etching and post-etching cleaning steps. Samples were prepared by partial etching of the photoresist patterned wafers exposed to some or all of the cleaning steps prior to electrochemical steps in an added droplet of water. Electrochemical data provided a quantitative measure of the effects of the selected plasma chemistry and post cleaning steps on corrosion and facilitated making choices for optimizing the reactive ion etching processes.