Application of BaTiO_3 Film Deposited by Aerosol Deposition to Decoupling Capacitor

摘要

By using aerosol deposition, BaTiO_3 films of more than 0.5 μm thickness were fabricated at room temperature on metal substrates. The dielectric constant of the films was 80 and their tan & was 0.02 at 1 MHz. The change in the temperature characteristics of the capacitance of the films was rectilinear from room temperature to 180℃. The films were fabricated on the substrates with Ra values of 0.011 and 0.048 μm. The breakdown voltages of the films were measured: the maximum value was 220 V/μm. The volume resistivities of thin films depended on film thickness. They stabilized at a value of 10~(12) Ω-cm when the film thickness was 5μm or more. These electric properties are considered to depend on film density. We manufactured a noise-cutting probe with a decoupling capacitor as an inspection apparatus for microwave devices in trial production using the BaTiO_3 films fabricated by aerosol deposition. The contact probe had a 0.3 mm diameter, a 5 mm length, and a 6-μm-thick BaTiO_3 film on the outer surface. Its capacitance was 0.5 nF. Its withstand voltage was 700 V. These values are sufficient for this application.