Surface-bound nanoparticles for initiating metal deposition

An alternative activation method was developed via binding electroless catalysts onto silicon substrates with 3-aminopropyltriethoxysilane (APTS) self-assembled monolayers (SAMs). Atomic force microscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy were used to characterize the laden of tin-free Pd(II)-based nanoparticles on silicon surfaces. The results indicate that the formation of coordination bonds between Pd ions and nitrogen atoms of APTS SAMs serves the important binding mechanism. Electroless copper deposition was successfully initiated by the catalyzed substrates and high quality Cu deposition was obtained. Owing to the chemically bound catalyst, this approach has advantages over the conventional Sn–Pd combined activation process, including reduced steps and improved longevity of initiator and enhanced adhesion of the deposition to the substrates.