Mechanical properties of ZrC thin films grown by pulsed laser deposition

ZrC thin films were grown by the pulsed laser deposition technique on (001) Si, (111) Si and (001) sapphire substrates. The structure and composition of the films were investigated by x-ray diffraction, x-ray reflectivity, and Auger electron spectroscopy investigations. Films grown at temperatures higher than 700°C under very low water vapor pressures exhibited a high degree of crystallinity. According to x-ray diffraction and pole figure investigations, ZrC films deposited on (001) Si are very well aligned with the substrate, both in-plane and out of plane, in a cube on cube manner. ZrC films deposited on (111) Si and sapphire grew with the (111) axis perpendicular to the substrate, while in-plane orientation depended on the particular orientation of the substrate. Nanoindentation measurements showed higher values of the hardness for higher crystallinity. For the highest crystalline quality, (111) ZrC films deposited on sapphire, values over 450 GPa for the elastic modulus and 30.4 GPa for the hardness were measured.