The Effectiveness of Aqueous Cleaning for the Removal of Evaporated Iron and Copper from Silicon Surfaces

Abstract

We have examined the ability of a variety of standard aqueous chemical cleaning procedures to remove trace quantities of thermally evaporated copper and iron from the surfaces of silicon substrates. We determined that the technique for preparing the Si wafer surface prior to metal deposition had a significant impact on the experimental results. This suggest that the silicon surface chemistry and the chemical bonding of the metal impurities to the surface plays an important role in determining the cleaning efficiency of a given wet chemical processing sequence.