A review of molecular beam epitaxy of ferroelectric BaTiO₃ films on Si, Ge and GaAs substrates and their applications

Abstract

SrTiO₃ epitaxial growth by molecular beam epitaxy (MBE) on silicon has opened up the route to the monolithic integration of various complex oxides on the complementary metal-oxide–semiconductor silicon platform. Among functional oxides, ferroelectric perovskite oxides offer promising perspectives to improve or add functionalities on-chip. We review the growth by MBE of the ferroelectric compound BaTiO₃ on silicon (Si), germanium (Ge) and gallium arsenide (GaAs) and we discuss the film properties in terms of crystalline structure, microstructure and ferroelectricity. Finally, we review the last developments in two areas of interest for the applications of BaTiO₃ films on silicon, namely integrated photonics, which benefits from the large Pockels effect of BaTiO₃, and low power logic devices, which may benefit from the negative capacitance of the ferroelectric.

• molecular beam epitaxy
• ferroelectric
• semiconductor

Acknowledgments

C Magen from Laboratorio de Microscopi´as Avanzadas (LMA), INA-Universidad de Zaragoza, Spain is acknowledged for his contribution to the STEM-HAADF image acquisition. This work was supported by the LABEX iMUST (ANR-10-LABX-0064) of Université de Lyon, within the program ‘Investissements d’Avenir’ (ANR-11-IDEX-0007) operated by the French National Research Agency (ANR). The ANR is also acknowledged for financial support through the program ‘Investissments d’Avenir’ (ANR-10-EQPX-38-01) and support through the grant ANR-14-CE26-0010 (project INTENSE). PFM work was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Support (SMY and SVK) was provided by a DOE Presidential Early Creer Award for Scientists and Engineers. The work (SMY) was also partially supported by IBS-R009-D1.