Abstract

BaTiO3 thin films, 50-60 nm in thickness, were evaporated in Ultra High Vacuum as well as under 1 mPa O2 pressure onto Si/SiO2 (30 nm) wafers. The substrate temperature during the evaporations was approximately 70°C. The films were flash annealed in oxygen at 500°C. The interfacial reactions were studied by XPS and AES Ar ion assisted depth profiling, and by RBS Interdiffusion took place even at 70°C. The XPS/AES depth profiles suggested strong interdiffusion, with Ba being the dominant moving species. The SiO2/BaTiO3 interface smears out with significant Ba concentrations up to half of the SiO2 thickness. Ti diffusion is remarkably lower. Barium is detected up to the SiO2/Si interface.