Properties of BaBi2Ta2O9 thin films prepared by chemical solution deposition technique for dynamic random-access memory applications

We report on the properties of BaBi2Ta2O9 (BBT) thin films for dynamic rand om-access memory (DRAM) and integrated capacitor applications. Crystalline BET thin films were successfully fabricated by the chemical solution deposi tion technique on Pt-coated Si substrates at a low annealing temperature of 650 degrees C. The films were characterized in terms of structural, dielec tric, and insulating properties. The electrical measurements were conducted on Pt/BET/Pt capacitors. The typical measured small signal dielectric cons tant and dissipation factor, at 100 kHz, were 282 and 0.023, respectively, for films annealed at 700 degrees C for 60 min. The leakage current density of the films was lower than 10(-9) A/cm(2) at an applied electric field of 300 kV/cm. A large storage density of 38.4 fC/mu m(2) was obtained at an a pplied electric field of 200 kV/cm. The high dielectric constant, low diele ctric loss and low leakage current density suggest the suitability of BET t hin films as dielectric layer for DRAM and integrated capacitor application s.