It is known that aluminum will readily form aluminum hydroxide during aqueous exposures. Thick oxide layers with a typical pseudoboehmite (fibre-like network) structure and bayerite crystals were observed on the aluminum metallization after the aqueous cleaning process. The study investigated the effect of a deionized (DI) water cleaning process (recently implemented to replace CFC-based cleaning technology) on the surface chemistry and corrosion behaviour of aluminum wire bond pads. The study also correlated the wire bond yield and oxide thickness with various water cleaning process parameters. The wire bond yield and reliability issues are discussed briefly.