Does Chemistry Really Matter in the Chemical Vapor Deposition of Titanium Dioxide? Precursor and Kinetic Effects on the Microstructure of Polycrystalline Films

摘要: A side-by-side comparison of the TiO2 deposition kinetics and corresponding microstructures was studied. The two precursors were titanium(IV) isopropoxide anhydrous nitrate, all depositions conducted at low pressures (<10-4 Torr) in an ultrahigh vacuum chemical vapor reactor. For both qualitatively similar exhibited three distinct regimes as a function temperature. At lowest temperatures, growth limited by rate precursor reaction on substrate surface. intermediate temperatures flux-limited obtained, highest rates decreased with increasing temperatures. overall behavior modeled quantitatively for each using two-step mechanism involving reversible adsorption followed irreversible reaction. Titanium(IV) nitrate lower activation energy (Er = 98 kJ/mol) which allowed compared to tit...