Tunable strontium titanate thin films for microwave devices

Abstract In this paper, strontium titanate (SrTiO3) thin films on platinized sapphire substrates have been demonstrated as a possible material candidate for tunable microwave device applications. Room temperature capacitance-voltage measurements at 1 MHz demonstrated a tunability of nearly 1.7:1 (41%), with a zero bias quality factor of 342 (tan 8 = .00292). Tunability of 1.75:1 (43%) is achieved with a device quality factor of 146 at 100 MHz. A device quality factor of 40 and a tunability of 1.7:1 (41%) has been obtained at frequencies up to 15 GHz.