From this perspective zirconium diboride ZrB2 with a hexagonal AlB2-type structure is an interesting alternative seen from a melting point of 3245 °C that is favorable in high-temperature CVD processes. It also demonstrates a high chemical stability to withstand corrosive gases such as hydrogen (H2), ammonia (NH3), triethylboron (TEB, B(C2H5)3) or silane (SiH4) typically applied as precursors in CVD. The low electrical resistivity 7.0 × 10 -6 Ω.cm of ZrB2 as well as high reflectivity and low absorption between 5 and 6 eV makes it promising as electrical contact for UV-devices. A further benefit is that epitaxial ZrB2 films can be deposited by direct current magnetron sputtering (DCMS) on the substrates typically applied in CVD of sp -BN films, i.e. Al2O3(0001) and 4H-SiC(0001) . Comparing the inplane lattice parameters of h-and r-BN (a = 2.504 Å) and of ZrB2 (3.168 Å), the relative mismatch of sp -BN to ZrB2 is relatively high (-21.0 %), but from a "magic mismatch" with five sp -BN unit cells over four ZrB2 surface unit cells it decreases down to -1.2 %.