A corrosion that results from the interaction of gold with aluminum that contains more than 2% silicon. At temperatures greater than 167°C, the silicon will act as a catalyst to create an aluminum-gold alloy. The resulting metallic migration results in gaps (called Kirkendall voids) in the gold-aluminum interface. Bimetallic contamination can decrease bond wire adhesion and can lower current carrying capability at the interface. In extreme cases, bond wires will actually lift from the pad. Bimetallic contamination is frequently referred to a§ "purple plague."