Dielectric properties of highly (100) oriented (Pb0.5,Sr0.5)TiO3 thin films grown on Si with MgO buffer layer

Abstract

Pb 0.5 , Sr 0.5 Ti O 3 (PST) thin films were deposited on Si with MgO (100) buffer layer by the alkoxide-based sol-gel method. Structural and dielectric properties of PST thin films for the tunable microwave device applications were investigated. For the MgO∕Si buffer layer, the PST thin films exhibited highly (100) orientation. The MgO buffer layer affects the stress state of the (100)-oriented PST thin films. The dielectric constant, tunability, and figure of merit of the highly (100)-oriented PST thin film increased with increasing annealing temperature due to the decrease in lattice distortion. The differences in dielectric properties may be attributed to the change in the film stress. The dielectric constants, dielectric loss and tunability of the PST thin films deposited on the MgO∕Si substrates measured at 10kHz were 822, 0.025, and 80.1%, respectively.