Stability of BaTiO ₃ thin films on Si

A very high quality BaTiO ₃ /p-Si interface and BaTiO ₃ insulator gates with high dielectric constant and low leakage current were produced by RF magnetron sputtering of BaTiO ₃ on (100) p-Si at a substrate temperature of 500°C, followed by in situ annealing at 500°C for 10 min. The reliability of the dielectric, however, plays an important role in determining the practical usage of ferroelectric random access memory applications. Thermal treatment of Au/BaTiO ₃ /Si capacitors at 150°C for 800 h showed no change of leakage current and a slight increase in leakage from 1.1 × 10 ^-9 A/cm ² for the as-deposited BaTiO ₃ to 1.8 × 10 ^-9 A/cm ² for the samples after 1000 h at a field of 1.3 × 10 ⁵ V/cm. The effects of fatigue were also studied and found to not affect the electrical and charge properties of BaTiO ₃ on Si for 10 ¹⁰ cycles of fatigue.