Confinement-free annealing induced ferroelectricity in Hf0.5Zr0.5O2 thin films

The structural and electrical properties of Hf0.5Zr0.5O2 thin films after post deposition and post metallization annealing were investigated. The possibility of the annealing without top electrodes for attainment of ferroelectric properties in Hf0.5Zr0.5O2 thin films was demonstrated. It was, however, shown, that the annealing in presence of top electrode leads to the more preferable crystallization to polar o-phase and the increase in the remanent polarization value. The influence of the film thickness on the structural and ferroelectric properties was studied both after post metallization and post deposition annealing. The optimal Hf0.5Zr0.5O2 thickness was found to be equal to similar to 19 nm for electrode free annealing, which is promising value for modern nanoscale ferroelectric devices. (C) 2015 Elsevier B.V. All rights reserved.