Low-temperature processing of sol-gel derived La0.5Sr0.5MnO3 buffer electrode and PbZr0.52Ti0.48O3 films using CO2 laser annealing

Abstract

Fabrication of well-crystallized sol-gel derived (La0.5Sr0.5)MnO3 (LSMO) buffer electrode layers and ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin films using a continuous wave CO2 laser annealing technique at a relatively low temperature was studied on a Pt/Ti/SiO2/Si substrate. Resistivity, carrier concentration and Hall mobility of laser-annealed conducting oxide LSMO films were optimized by changing the radiation fluence and the substrate temperature. The minimum resistivity of 1.27×10−4 Ω cm was obtained for LSMO/Pt(Si) films prepared by laser irradiating at a fluence of 533 W/cm2 with a simultaneous substrate heating at a temperature of 300 °C. The laser-annealed PZT films coated on LSMO/Pt(Si) substrate shows enhancement in remanent polarization from 10.1 to 17.3 μC/cm2 as the PZT irradiated with a laser fluence of 433–483 W/cm2. The PZT(483 W/cm2)/LSMO(533 W/cm2)/Pt(Si) films showed a good fatigue resistance after 1×1010 switching cycles with a bipolar electric field of 300 kV/cm, implying the feasibility of fabricating reliable ferroelectric-oxide electrode heterostructures using CO2 laser annealing at temperatures lower than 400 °C.