Stresses in Ferroelectric Thin Films

Abstract

ABSTRACTThe stresses in rf sputtered BaTiO3 thin films, deposited on both Si and sapphire single crystals, were studied. From the measured total film stress values, both the intrinsic stresses in the film and the elastic coefficients [Ef/(1–vf)] of the film were obtained. BaTiO3 films can be obtained in any stress state (tensile, stress free or compressive) by varying the deposition temperature, deposition pressure, and substrate. At lower temperatures and pressures compressive intrinsic stresses were observed whereas, at high deposition temperatures and pressures intrinsic stresses were tensile in nature. The [Ef/(1–vf)] value approached the single crystal value for films deposited at low pressures and decreased significantly with increasing deposition pressure.