Plasma enhanced chemical vapour depositon of ZrO₂ based layers

Chemical vapour deposition (CVD) is a widely applied technique used for thin film deposition. The combination with a plasma source (PECVD) enables the fine-tuning of parameters, opening new possibilities for the fabrication of functional coatings, such as thin thermal barrier coatings.

An evaporated metalorganic precursor is transported into the reaction chamber by a nitrogen-flow of 25-50 sccm at pressures of about 100 Pa. A ZrO₂ layer is deposited onto a heated substrate in the centre of the chamber. The desired layer growth rate lies at > 500 nm/h and the layer thickness at < 30 µm.

To influence and improve the reaction chemistry, a microwave plasma source is mounted opposite the substrate surface. The discharge interacts with the incoming precursor molecules, with the aim to reduce the reaction temperature.

During this process, the growth rate and substrate temperature are monitored by in-situ ellipsometry to obtain insights into chemical kinetics and mass transport phenomena. The deposited layers are characterised in stoichiometry and crystallinity, using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD).

Depositions are carried out with and without the use of the plasma source. The different growth characteristics are investigated and compared.