First-principles quantum chemical calculations have been performed to reveal the adhesion mechanisms of metal impurities (Al or Fe! onto the Si wafer surface in alkali solution. As typical hydroxyl complexes of these metals, Al(OH)(4)(-), Fe(OH)(3) . 3H(2)O, or [Fe(OH)(4) . 2H(2)O](-) are used in computation. The lowest energy paths of the adhesion reaction have been obtained for the respective complex when the Si surface is terminated with OH groups and develops into a hydrophilic condition. The potential energy changes along these reaction paths were evaluated and the probabilities of the metal adhesion were compared. The detaching mechanism was also investigated for Al or Fe hydroxyl complex compounds in which a water molecule attacks the Si-O or O-metal bond at the interface between the complex and the surface. The results are discussed in comparison with recent experimental findings. (C) 2004 The Electrochemical Society.