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 zi rconium bis(phosphonate) films on silicon substrates under water. We o bserved a monolayer of zirconium 1,16-hexadecanediylbis-(phosphonate) [Zr(O3P-(CH2)(16)-PO3)] depositing as ''islands'' on a zirconium-deriv atized silicon wafer. Images of the zirconated substrate obtained afte r short exposure to a H2O3P-(CH2)(16)-PO3H2 (C(16)BPA) solution corres pond to an incomplete monolayer. The surface roughness for an incomple te monolayer is seven times greater than the initial zirconated surfac e. Upon further exposure to the C(16)BPA solution, the surface roughne ss decreases and is ultimately very close to that of the original zirc onated substrate. The Zr C(16)BPA film is almost completely formed aft er a deposition time of approximate to 200 min. AFM images of an incom plete bilayer dim show regions corresponding to the zirconated substra te and monolayer and bilayer coverage.