Zirconocene Alkoxides, promising precursors for MOCVD of zirconium dioxide thin films

Some new volatile bis-cyclopentadienyl zirconium alkoxides of the type Cp 2Zr(OR)(O tBu) (R = iPr, Et, Me) is synthesized by the reaction of the corresponding KOR with the intermediate Cp 2ZrCl(O tBu). Moreover, an alternative and convenient synthesis of Cp 2Zr(O tBu) 2, based on the reaction of Cp 2ZrCl 2 with an excess of tert-butanol and triethylamine, is reported. The obtained compounds are identified by chemical analyses, thermogravimetric measurements, infrared (IR), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). Furthermore, a crystallographic study of Cp 2ZrCl(O tBu) is also reported. Cp 2Zr(O tBu) 2 and Cp 2Zr(O iPr)(O tBu) are then used for depositing zirconia thin films of high quality and purity on Si(100) and stainless steel AISI 316 substrates by metal-organic (MO)CVD. The microstructure and composition of the deposits are investigated by X-ray diffraction (XRD) and secondary ion mass spectrometry (SIMS), while their hardness and elastic recovery on the AISI 316 substrate are measured using load-depth nano-indentation tests. The outcomes are consistent with a significant increase in the Berkovich hardness of the coated samples compared to that of bulk AISI 316.