Orientation and composition dependence of piezoelectric dielectric properties of sputtered Pb(Zr{sub}x,Ti{sub}(1-x)O{sub}3 thin films

摘要

In-situ, reactively sputter deposited 300 nm thick Pb(Zr{sub}x,Ti(1-x))O{sub}3 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 TiG{sub}9 film. Highly {100} oriented PZT is grown on Pt (111) by means of a 10 nm thick PbTiO{sub}3 seed layer. Pronounced deviations from known bulk PZT behavior are observed for the (111) texture. Maximum of d{sub}33 and ε are shifted to 40/60 and 45/55 compositions, respectively. (100) textured films exhibit a higher d{sub}33. 1.3μm (100) thick films attain the predicted d{sub}33 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 O{sub}2 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 without poling treatments.