Epitaxial growth of SrTiO3 films on CeO2/yttria-stabilized zirconia/Si(001) with TiO2 atomic layer by pulsed-laser deposition

Epitaxial SrTiO3 (STO) films were fabricated on CeO2/yttria-stabilized zirconia(YSZ)/Si(001) substrates by the insertion of a TiO2 atomic layer by pulsed-laser deposition. X-ray diffraction and reflection high-energy electron diffraction showed that epitaxial STO films with different out-of-plane orientations have been obtained by controlling the thickness of the TiO2 atomic layer. A stoichiometric STO film directly deposited on CeO2/YSZ/Si was preferentially (110) oriented with a STO[1̄10]∥CeO2[100] epitaxial relationship. On the other hand, 1 monolayer (ML) TiO2-covered CeO2/YSZ/Si resulted in STO(001) film epitaxially growth with a STO[110]∥CeO2[100] relationship. However, as the TiO2 thickness exceeded 1 ML, the orientation of STO film drastically changed to (111) orientation having a STO[011̄]∥CeO2[100] epitaxial relationship. These results indicate that the atomic layer thickness dramatically controls the film epitaxial growth.