Orientation and Composition Dependence of Piezoelectric-Dielectric Properties of Sputtered Pb(Zrx,Ti1-x)O3 Thin Films

Abstract

AbstractIn-situ, reactively sputter deposited 300 nm thick Pb(Zrx,Ti1-x)O3 films on Pt/Si based substrates are investigated as a function of composition and texture. (111) PZT is grown on a (111) oriented Pt bottom electrode covered with a very thin TiO2 film. Highly {100} oriented PZT is grown on Pt (111) by means of a 10 nm thick PbTiO3 seed layer. Pronounced deviations from known bulk PZT behavior are observed for the (111) texture. Maximum of d33 and ε are shifted to 40/60 and 45/55 compositions, respectively. (100) textured films exhibit a higher d33. 1.3 μm (100) thick films attain the predicted d33 value of clamped bulk ceramics. Coercive fields and voltage offsets increase strongly with increasing Ti content. In parallel, the as-grown polarization increases. Polarization switching is not possible for x ≤ 0.1. Post-anneals in O2 and hot poling show that oxygen vacancies play an important role in this phenomenon. Ti-rich (100) oriented films exhibit very high and stable pyroelectric and piezoelectric coefficients whithout poling treatments.