A NOVEL ACTIVATION PROCESS FOR AUTOCATALYTIC ELECTROLESS DEPOSITION ON SILICON SUBSTRATES

An improved activation process using a PdCl2-HF-NH4F system for the ac tivator solution is reported. The process is applicable for autocataly tic electroless deposition of metals on rough as well as smooth/polish ed, n- and p-type silicon substrates of all doping levels. Using the i mproved 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 technol ogy. The activator avoids the use of tin, which is undesirable in devi ce fabrication.