Zirconium diboride, ZrB₂, is a ceramic material with bulk properties such as high melting point (3245 °C), high hardness (23 GPa), and low resistivity (~8 μΩcm). Thin film growth of ZrB₂ using physical vapor deposition has suffered from problems with films deviating from stoichiometry and with high levels of contaminants, especially high oxygen content. The homogeneity range of ZrB₂ is very narrow, and consequently it is vital to achieve the correct stoichiometry to grow films with high crystalline order.

This thesis describes a direct current magnetron sputtering process to grow stoichiometric ZrB₂ thin films with a low degree of impurities. Growth of epitaxial ZrB₂ films was achieved on 4H-SiC(0001), Si(111) and Al₂O₃(0001) substrates. The effect of deposition temperature and power applied on the sputtering target was investigated and showed that high power density (8.77 Wcm^-2) and high temperature (900 °C) resulted in films with the best composition and the highest crystal quality. ZrB₂ films on GaN(0001) templates exhibit an amorphous layer at the film-substrate interface and the resulting films are either polycrystalline or textured.

Resistivity measurements showed that the ZrB2 thin films exhibit typical resistivity values of ~100-250 μΩcm and that the resistivity decreased with increasing deposition temperature.

Nanoindentation was applied to assess the mechanical properties of the films. The epitaxial ZrB₂ films exhibit high elastic recovery and a hardness of ~45-50 GPa, twice as high as the literature bulk value. In addition, evaluation of the mechanical properties was performed at high temperatures of up to 600 °C and showed that the epitaxial films retained a higher hardness, compared to textured ZrB₂ films and bulk, also at these temperatures.