Development of Multilayered SrTiO3 Thin-Film Capacitors For Embedded Passive Applications

Multilayered thin-film capacitors (MLTFC) with SrTiO₃ (STO) dielectric and Pt electrode thin layers were fabricated on polycrystalline alumina substrates, in which amorphous STO dielectric thin layers with thicknesses of 100-300 nm were formed using a cost-effective aerosol chemical vapor deposition (ASCVD) method. The MLTFC with up to ten-layer dielectric layers and total thickness of 0.2-0.25 mm, reached capacitance densities of 100-900 nF/cm². Further increase in capacitance density of the MLTFC was tried by reduction in thickness and crystallization of STO dielectric thin layers. Three forms of MLTFC (chips, sheets and substrates) are being developed for embedded passive applications.