Controlled Electroless Deposition of Noble Metal Nanoparticle Films on Germanium Surfaces

Thin noble metal films have been prepared as a result of the immersion of germanium substrates into dilute, aqueous solutions of AuCl4-, PdCl42-, or PtCl42-, respectively. Deposition proceeds via galvanic displacement in the absence of fluoride, pH adjusters, complexing agents, or external reducing agents. This manner of metal deposition serves as a cost-effective, high-throughput methodology with control over surface morphology and deposition rate by modulation of plating parameters such as concentration, temperature, and immersion time. Recent progress toward metallization on the diminishing size regimes dictated by the feverishly evolving disciplines of nanotechnology has imposed increasingly stringent demands upon thin film preparation methodologies.1 Ultra large scale integration (ULSI) device fabrication, nanoelectromechanical systems (NEMS), and arrayed nanosensors will require unparalleled control of metal film surface morphology, deposition rate, and substrate adhesion without sacrificing throughput or cost effectiveness. Furthermore, noble metal films of this type are important for fundamental investigations