Integration of BaTiO3ferroelectric thin films with GaAs for functional devices

The integration of ferroelectric oxides with GaAs could enable monolithic optoelectronic integrated circuits, advanced metal-insulator-semiconductor structures, and multifunctional optoelectronic devices. BaTiO₃ is a good candidate for this integration due to the large spontaneous polarization and large electro-optic effects, but presents a challenge due to the large lattice mismatch and difficulty in achieving a crystalline oxide interface on GaAs. In this paper we investigate the deposition of BaTiO₃ onto GaAs by pulsed laser deposition using varied substrate preparation techniques and MgO buffer layers. Highly oriented [001] BaTiO₃ thin films are achieved exhibiting spontaneous polarization characteristic of ferroelectric material.