Ferroelectric BaSrTiO₃ films structured by an intermediate annealing during the deposition

ABSTRACT

(Ba,Sr)TiO₃ layered thin films were grown by radio-frequency magnetron sputtering of a ceramic target on Pt/Ti-buffered sapphire substrate. The structural and microwave properties of the films were improved by an intermediate annealing of the layers during the growing process. Ferroelectric tunable capacitors based on these films show a tunability n = 83% at electric field strength of 80 V/μm, an absence of the capacitance slow relaxation up to 40 V/µm and the dielectric losses not higher than 4% at frequency of 2 GHz. These values represent substantial improvements when compared to conventionally grown tunable dielectric films.

KEYWORDS:

• Ferroelectrics; microwave applications; structured films

Funding

This work was supported by Russian Science Foundation research project No 15-19-10049.