The influence of the SrTiO3 buffer layer on the ferroelectric properties of the Si0.5Sn0.5ZnO3 thin films prepared by the pulsed laser deposition technique

Abstract

The pulsed laser deposition (PLD) technique is employed in this research to fabricate thin films of Silicon-doped Tin Zinc Oxide (Si-SnZnO3) on a Magnesium Oxide (MgO) substrate. Additionally, Si-SnZnO3 thin films are grown on a Strontium Titanate (SrTiO3 or STO) buffer layer with a thickness of 60 nm, which is deposited on the MgO substrate. The target materials used in the PLD technique, Si-SnZnO3, and SrTiO3, are prepared using the solid-state technique. The current study aims to explore the influence of the STO buffer layer on the ferroelectric behavior of the Si-SnZnO3-grown film. Accordingly, the structure, morphology, and film thickness of Si0.5Sn0.5ZnO3/MgO and Si0.5Sn0.5ZnO3/STO/MgO samples are investigated using X-Ray Diffraction and Scanning Electron Microscope techniques respectively. Furthermore, the uniformity of different film thicknesses grown on STO/MgO is investigated using Atomic Force Microscopy. Both the resistivity and the carrier mobility for Si0.5Sn0.5ZnO3 /MgO sample are 3.22 × 103 Ω.m, and 7.35 × 107 m/(V⋅s) (semiconductor), whereas there are 4.31 × 103 Ω.m, and 63.1 m/(V⋅s) (insulator) for the Si0.5Sn0.5ZnO3/STO/MgO substrates, respectively. The Polarization-Electric Field hysteresis loops of different film thicknesses show Lossy capacitor response and Non-linear ferroelectric response for Si0.5Sn0.5ZnO3/MgO, and Si0.5Sn0.5ZnO3/STO/MgO, correspondingly. Moreover, the ferroelectricity parameters of the Si0.5Sn0.5ZnO3 films deposited on the STO/MgO were improved by an order of magnitude compared to the thin film on the MgO substrate. The obtained results indicate that Si0.5Sn0.5ZnO3/STO/MgO configuration could be suitable for Ferroelectric Random Access Memory applications.