Ceramic thin films deposited on Si(100) by laser ablation: Application as buffer layers for YBa2Cu3O7 films

Ceramic thin films of yttria-stabilised zirconia (YSZ), SrTiO3(STO) and CeO2 have been deposited on Si(100) substrates by laser ablation. The films have been characterized by X-ray diffractometry, field emission scanning electron microscopy and secondary ion mass spectrometry (SIMS). The effects of the oxygen partial pressure during deposition and the substrate temperature were studied. All the films have preferential orientation: (h00) and (hh0) for STO and (hhh) for CeO2 and YSZ. The films show a low density of particulates and a very smooth surface. SIMS profiles indicate a low interdiffusion between film and silicon. One of the applications of these materials is their use as a buffer layer for the growth of YBCO on silicon. Because both materials are highly reactive, it is necessary to put a barrier between YBCO and silicon. For this purpose we used the ceramic films previously deposited in order to obtain superconducting YBCO films. The deposited YBCO films present good superconducting properties with zero resistance at temperatures between 80 and 85 K.