STRUCTURAL AND DIELECTRIC PROPERTIES OF BARIUM STANNATE TITANATE THIN FILMS FOR MICROWAVE TUNABLE DEVICES AND MULTIFUNCTIONAL SENSORS

ABSTRACT

Dielectric oxides have recently attracted much attention in a wide range of applications such as in memory devices, microwave tunable devices, and chemical sensors. Recently Ba(Ti_1−x, Sn_x)O₃(denoted as BTS) solid solutions have received attention because of their high dielectric performance, lead-free relaxor behavior and sensor applications. Especially, the system has high dielectric constant and low dielectric loss around room temperature. It is very interesting to investigate the structural and dielectric properties of BTS thin films. In this works, we report on the growth, structural and dielectric properties of Ba(Ti, Sn)O₃ (BTS) for high-performance microwave tunable device and sensor applications. BTS thin films were deposited on MgO substrates. The dielectric properties of BTS thin films were carried out using planar interdigitated (IDT) capacitor. IDT capacitor based on an epitaxial BTS film exhibited the large capacitance tunability of 82% at a frequency of 100 kHz and applied voltage of 40 V, and that it is a promising candidate for high-performance microwave tunable devices at room temperature.

Keywords:

• BTS films
• dielectric tunability
• phase shifter
• oxide sensor
• interdigitated capacitor

ACKNOWLEDGMENTS

This work was supported by the R&D program of MOST of Korea [Project No. 2200-S]