Templated electroless nickel deposition for patterning applications

Electroless nickel deposition is a chemical reduction technique commonly used for coating on metals. Deposition on non-metallic substrates is challenging owing to their poor ability to catalyse the reaction. The kinetics data for electroless nickel is limited, especially for different activation techniques. In this work, we show that gold-palladium sputter activation can be used for electroless nickel growth on glass substrates. Deposition kinetics is measured and compared with standard metallic substrates to elucidate the growth mechanism. By tracking film thickness as a function of temperature and time, we extracted the activation energies for different substrates and surface activation techniques. Activation energy, at a pH of 5.6, for bare SS316 is 3.4 kJ/mol, while for sputter activated substrate it is 73.9 kJ/mol. We also demonstrate that sputter activation can be used to obtain patterned electroless films, by performing lithography assisted area selective deposition and by fabricating a patterned transmission line, with close dimensional tolerance. The process might be extended to other electroless systems as well.