Structure and electrical properties of MgTiO3 thin films deposited by rf magnetron sputtering

Abstract

Bulk MgTiO3 ceramics have shown excellent dielectric properties at microwave frequencies; however, the high sintering temperature of the bulk materials is major obstacle in their use as dielectric resonators to miniaturize microwave circuits. In this article, MgTiO3 thin films were fabricated on n-type Si(100) substrates by rf magnetron sputtering by using MgTiO3 target which was synthesized in the experiment. It was possible to obtain highly oriented MgTiO3(110) thin film at a rf power density of 7.7W∕cm2 and a substrate temperature of 400°C, which is much lower than the bulk sintering temperature. These films were studied by choosing different rf power densities and substrate temperature. The microstructure and surface morphology of the MgTiO3 films deposited on Si(100) was determined by x-ray diffraction (XRD), scanning electron microscopy, and atomic force microscopy. The XRD showed that the deposited films exhibited a polycrystalline microstructure. The grain size of the film increased with an increase in the rf power density and substrate temperature. The electrical properties were measured using C-V and current-voltage I-V measurements on metal-insulator-semiconductor capacitor structures. As rf power density of 7.7W∕cm2 and substrate temperature of 400°C, a dielectric constant of 14.9 (f=10MHz) and a dissipation factor of 0.031 were obtained.