S. Karmalkar et al., A NOVEL ACTIVATION PROCESS FOR AUTOCATALYTIC ELECTROLESS DEPOSITION ON SILICON SUBSTRATES, Journal of the Electrochemical Society, 144(5), 1997, pp. 1696-1698
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.