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Ferroelectric thin films of BaTiO3 have been successfully deposited on n-type silicon substrates at temperatures above 500 °C by rf sputtering in an O2/Ar atmosphere. Analysis by x-ray diffraction patterns show that films deposited at room temperature are amorphous. At temperatures above 500 °C, crystalline BaTiO3 films with a tetragonal structure are obtained. The polarization-electric field (P-E) hysteresis loops and a broad peak in the dielectric constant versus temperature curve at Curie point indicate that the rf sputtered BaTiO3 films are ferroelectric. An anomalous photovoltaic effect is observed in these thin films which is related to the remanent polarization of the material. The results on open-circuit and short-circuit measurements provide an important basis for a better understanding of the role of photovoltaic field, photovoltaic current, and the pyroelectric properties in photoferroelectric domain switching.

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This study focused on measuring the stress of TiN films prepared by rapid thermal processing, by sputtering, and by furnace annealing. Also included in the study were W and Al alloy films. The stress measurements were done at room temperature, and then further data were collected with temperature up to 870 °C for W and TiN. Al alloy films were temperature cycled up to 500 °C. Film structure was studied by transmission electron microscopy (TEM) analysis prior to and just after thermal cycling. Hysteresis curves were obtained for all films. Graphical stress temperature correlations were made for films of different thicknesses. TEM results of TiN films prepared by rapid thermal processing, furnace annealing, and sputter deposition, indicated a reduction in grain size along with an increase in the tensile stress upon completion of thermal cycling of the films.