We have developed a "two-step" solution-based processing to deposit high-k ceramic thin films. Electrochemically pre-coated amorphous titania layers were "hydrothermally" or "hydrothermal-electrochemically" converted to crystalline BaTiO3 films at <= 90 degrees C. In hydrothermal process, an in situ electrochemical protection (ECP) mechanism enables utilization of common metallic substrates (e.g., Cu), which otherwise suffer corrosion from the precursor. Microstructural evolution of BaTiO3 films along with the effectiveness of ECP is discussed in this article. Derived BaTiO3 shows a dielectric constant of similar to 80 at 100 kHz, which makes it a promising candidate for high-density microelectronic capacitor applications.