Electrical properties of strontium titanate thin films by multi-ion-beam reactive sputtering technique

Thin films of SrTiO3 were deposited by multi-ion-beam reactive sputtering technique using SrO and Ti-metal targets. The dielectric behavior of the films deposited on Pt-coated Si substrates showed thickness dependence. A dielectric constant of 219 at 100 KHz was found for 1.2 μm thick films. A charge storage density of about 15 fC/μm2 and leakage current density of 106 μA/cm2 at an electric field of 0.17 MV/cm were obtained for 0.3 μm films. The probable interface layers present between film and silicon substrate, in the case of metal-insulator-silicon configuration, appear to influence the electrical behavior. Preliminary analysis showed that the conduction of the films in high field region was bulk-limited Poole–Frenkel emission mechanisms.