A novel activation process for autocatalytic electroless deposition on silicon substrates

An improved activation process using a PdCl2-HF-NH4F system for the activator solution is reported. The process is applicable for autocatalytic electroless deposition of metals on rough as well as smooth/polished, n- and p-type silicon substrates of all doping levels. Using the improved activation process. adhesion of more than 8.33 x 10(6) N/m(2) for palladium deposits and 7.25 x 10(6) N/m(2) for nickel deposits has been obtained. The etch rate of SiO2 in the activator solution is low enough for it to be compatible with planar integrated-circuit technology. The activator avoids the use of tin, which is undesirable in device fabrication.