Fabrication of BaTiO₃ micropatterns by a combination of laserinduced pyrolysis method and nano-crystalline seeding technique and their dielectric properties

This paper describes a method for fabricating dielectric BaTiO₃ (BT) micropatterns. The method used in the present work is a combination of a laser-induced pyrolysis method and a nano-crystalline seeding technique. BT nano-crystalline particles used for the seeding are prepared by hydrolysis of a BT complex alkoxide. A precursor solution of a BT complex alkoxide containing the BT nano-crystalline particles and polyvinylpyrollidone (PVP) is spin-coated on a Pt substrate. Micropatterns with a line width of ca. 1-2 μm are fabricated by irradiating an Ar⁺ laser beam with a beam waist diameter of 0.74 μm at a laser energy density of 27 MW/cm² and a scanning speed of 25 μm/s on the spin-coated BT films, and then stripping laser-unirradiated regions on the films with an HCl aqueous solution. The use of BT particles prepared in the presence of PVP with a small molecular weight provides clear micropatterns and high dielectric constant. The dielectric constant and dissipation factor of the micropattern fabricated at 20 vol% BT particles with an average size of 12.9 nm prepared in the presence of PVP with a molecular weight of 10000 attain 78.7 and 0.089, respectively, for a measurement frequency of 100 kHz.