Publication Date:
2014-12-03
Description:
Integration of epitaxial complex ferroelectric oxides such as BaTiO 3 on semiconductor substrates depends on the ability to finely control their structure and properties, which are strongly correlated. The epitaxial growth of thin BaTiO 3 films with high interfacial quality still remains scarcely investigated on semiconductors; a systematic investigation of processing conditions is missing although they determine the cationic composition, the oxygen content, and the microstructure, which, in turn, play a major role on the ferroelectric properties. We report here the study of various relevant deposition parameters in molecular beam epitaxy for the growth of epitaxial tetragonal BaTiO 3 thin films on silicon substrates. The films were grown using a 4 nm-thick epitaxial SrTiO 3 buffer layer. We show that the tetragonality of the BaTiO 3 films, the crystalline domain orientations, and SiO 2 interfacial layer regrowth strongly depend on the oxygen partial pressure and temperature during the growth and on the post-deposition anneal. The ferroelectricity of the films, probed using piezoresponse force microscopy, is obtained in controlled temperature and oxygen pressure conditions with a polarization perpendicular to the surface.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
