Reactive ion etching induced corrosion of Al and Al‐Cu films

摘要

Aluminum and Al‐Cu conductor lines etched with a Cl containing plasma in low‐pressure diode systems corroded rapidly upon atmospheric exposure. The mechanisms underlying this corrosion problem were investigated using Auger electron and x‐ray photoelectron spectroscopies. Reactive ion etching resulted in a nonprotective oxide layer and thus rendered the etched samples more susceptible to atmospheric corrosion. Factors contributing to the increased reactivity of etched samples includes C and Cl contamination, radiation damage, and for Al‐Cu alloys, Cu enrichment. A thermal oxidation treatment at temperatures of ∼300–350 °C and l atm O2pressure for ≳30–45 min was found to be effective in restoring the protective oxide layer and thus improving the corrosion resistance of etched samples.