MECHANISTIC STUDIES OF FILM GROWTH OF ZIRCONIUM BIS(PHOSPHONATE) MONOLAYER AND MULTILAYER THIN-FILMS - THESE THINGS GROW DARNED FLAT

Atomic force microscopy (AFM) was used to study thin film growth of zirconium bis(phosphonate) films on silicon substrates under water. We observed a monolayer of zirconium 1,16-hexadecanediylbis-(phosphonate) [Zr(O3P-(CH2)(16)-PO3)] depositing as ''islands'' on a zirconium-derivatized silicon wafer. Images of the zirconated substrate obtained after short exposure to a H2O3P-(CH2)(16)-PO3H2 (C(16)BPA) solution correspond to an incomplete monolayer. The surface roughness for an incomplete monolayer is seven times greater than the initial zirconated surface. Upon further exposure to the C(16)BPA solution, the surface roughness decreases and is ultimately very close to that of the original zirconated substrate. The Zr C(16)BPA film is almost completely formed after a deposition time of approximate to 200 min. AFM images of an incomplete bilayer dim show regions corresponding to the zirconated substrate and monolayer and bilayer coverage.