Area selective OMCVD of gold and palladium on self-assembled organic monolayers: Control of nucleation sites

The area selective organometallic chemical vapor deposition (OMCVD) of gold and palladium onto self-assembled monolayers (SAMs) of omega -functionaliz ed long chain alkanethiols and 4'-functionalized biphenylthiols was investi gated. Trimethylphosphine-methylgold (Me3PAuMe) and cyclopentadienyl-allyl- palladium (Cp(allyl)Pd) were used as organometallic precursors. X-ray photo electron spectroscopy (XPS) revealed that in both cases nucleation occurs s electively only on thiol terminated surfaces even at very mild conditions w hereas nucleation is inhibited on methyl- and hydroxy-terminated SAMs. It h as been shown that it is possible to control the number of gold clusters pe r area by depositing gold onto mixed SAMs consisting of biphenylthiol and 4 '-biphenyldithiol with varying molar ratios.