Baking (Pb, La)(Zr, Ti)O3 capacitors in a hydrogen atmosphere causes a significant loss of remanent polarization even at 150 °C. The hysteresis variations depend on the polarization states during baking. The hysteresis loop showed voltage shifts when the capacitor was polarized before baking, whereas it became a cramped shape when the baking was carried out on a virgin capacitor. Although remanent polarization diminished in all cases, saturation polarization was not suppressed. The clamped hysteresis loop can be described as an average of two loops shifted to positive and negative voltages. The results indicate that the loss of remanent polarization is not due to the suppression of switching, but due to the shift of the hysteresis of each domain larger than the coercive voltage.

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SrTiO3 films sputter deposited directly on a Si substrate at 200 °C were annealed at a scanning cw Ar laser beam at a substrate temperature of 200 °C. The laser annealing improved the crystallinity of the SrTiO3 films and minimized the formation of a SiO2 layer between SrTiO3 and Si. These results are confirmed by x-ray diffraction analysis and secondary ion mass spectrometry. The dielectric constant of the SrTiO3 films increased monotonically with laser power up to 1.2 W. The dielectric constant was improved from the as-grown value of 26–118 for a 160-nm-thick SrTiO3 film annealed at a 1.2 W laser power. At 1.0 W laser power, the annealed dielectric constant varied from 55 to 101 with increasing film thickness from 110 to 380 nm. From the film thickness dependence constant, it is shown that the intrinsic dielectric constant for the SrTiO3 films is about 150.

Ruthenium dioxide ( RuO2) thin films are evaluated as a bottom electrode for SrTiO3. It was found that a thin RuO2(50 nm)/Ru(20 nm) layer on Si is quite effective as a barrier layer for both orygen atoms and metals when depositing SrTiO3 at a relatively low temperature of 450° C. To test its suitability for high-temperature processes such as CVD of SrTiO3, the RuO2/Ru electrode on Si was annealed in air at 600° C for 1 hour. Even under this severe condition, the electrode using 100-nm-thick RuO2 was sufficient for preventing oxygen diffusion into Si.