Study of compositional change in the interfacial regions between lead strontiumtitanate (PST)/SiO2 and lead zirconate titanate (PZT)/SiO2 by Auger emissionspectroscopy

摘要

Auger spectroscopy was used to study the compositional change in the interfacialregion between ferroelectric thin films, namely lead strontium titanate (PST)and lead zirconate titanate (PZT), and commercial available Si substrates with a200 nm thick thermal oxide layer. Both PST and PZT thin films were prepared viaa sol-gel spin coating method. The thin films from both materials were annealedunder the same conditions (temperature and time). It was found that strontiumstops the lead diffusion into SiO2 by forming SrTiO3 and/or SrO, maintaining awell defined SiO2 region, while PbSiO3 is formed in the PZT/SiO2 system. Theseresults are important for a general understanding of interdiffusions in materialinterfaces in particular for the realization of future high-dielectric-constant(high-k) oxide layers and for the next generation of advanced electronicdevices.