Excimer laser ablated strontium titanate thin films for dynamic random access memory applications

Abstract

Thin films of SrTiO₃ were deposited on platinum coated silicon and bare silicon by excimer laser (248 nm) ablation at 400 and 500° C or ex situ crystallized. Films deposited at 500° C showed good crystallinity and were characterized for dielectric constant, dielectric loss, leakage current and C-V characteristics. The films showed a dielectric constant of 240, a dissipation factor of 0.02, a leakage current of 2×10^-9 A/cm², and a charge storage density of 42 fC/µ m² at a bias of 5 V. The C-V behavior of both metal-insulator-metal (MIM) and metal-insulator- semiconductor (MIS) structures indicated bulk dielectric permittivity in the accumulation region and also good Si/SrTiO₃ interfaces.