Low-temperature synthesis of BaTiO3 thin films on silicon substrates by hydrothermal reaction

Abstract

Crystalline BaTiO3 thin films (0.2–1 μm) of dielectric constant 450–500 have been synthesized by the hydrothermal reaction of a titanium film (∼1 μm thickness) deposited on a silicon substrate with Ba(OH)2 solution (concentration 0.4 M) in the temperature range 100–200 °C. The reaction of the silicon substrate with the Ti film was prevented by deposition of a buffer layer of amorphous TiC between the Ti film and the Si substrate. The TiC not only prevented the diffusion of Si through the Ti layer but also allowed some reaction between itself and the Ti layer so that the adherence of the films was not degraded.