Chemical vapour deposition of ZrO₂ thin films monitored by IR spectroscopy

Thin films of ZrO₂ have been grown under kinetic control by decomposition of zirconium tetra-tert-butoxide onto quartz substrates. The resulting films have been characterised by optical and electron microscopy and X-ray diffraction. A phase transition from a poorly crystalline, metastable form of zirconia to the monoclinic phase showing a strong preferred orientation takes place as the substrate temperature is raised from 450 to 500°C. The decomposition of the precursor has been followed by ex situ infrared spectroscopy, allowing monitoring of the gas-phase products as a function of substrate temperature. The possible mechanism for the decomposition reaction is discussed.