Dielectric characterization of sol-gel derived Sn doped ZrTiO₄ thin films

High-quality thin film dielectric materials are critical for the next generation of integrated microwave devices. Much recent attention has been focused on ZrTiO₄ and Sn doped ZrTiO₄ films for applications in these devices. Sol-gel derived Sn doped ZrTiO₄ thin films were prepared on Si and platinized Si wafers and fired to temperatures ranging from 550°C to 700°C. Multiple spincoating was performed to obtain films up to 0.5μm thick, with intermediate firings at 400°C between coatings. The ZrTiO₄ films exhibited a dielectric constant of about 32 with low leakage currents of 2×10^-9 A. These films were crystalline when fired to 700°C or above. The addition of Sn lowered the dielectric constant but also improved the dissipation factor.