Yttria-stabilized zirconia films of different composition as buffer layers for the deposition of epitaxial diamond/Ir layers on Si(001)

Diamond/iridium/yttria-stabilized-zirconia (YSZ)/silicon is a promising multilayer structure for the future realization of single crystal diamond wafers. In the present work we studied the heteroepitaxial growth of YSZ films on Si(001) prepared by pulsed laser deposition. Films deposited from three ablation targets with different yttrium content were compared systematically. Depending on the specific target purely c-axis oriented tetragonal or cubic films were obtained. The films were epitaxial with a low mosaicity of about 1°. Iridium layers deposited on top by e-beam evaporation showed a perfect cube-on-cube epitaxial alignment on all types of YSZ films. The iridium films exhibit a smooth surface with only few holes. All the multilayer structures were stable in subsequent diamond nucleation processes via bias enhanced nucleation (BEN).