Deep Insights into the Failure Mechanisms in Field-cycled Ferroelectric Hf_0.5Zr_0.5O₂ Thin Film: TDDB Characterizations and First-Principles Calculations

Abstract

To address the failure mechanisms in ferroelectric devices, this work presents a systematical study on Hf <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</inf> Zr <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> -based ferroelectric memory. Firstly, by detail electrical characterizations of P-V and C-V curves in field-cycled devices, three dominant failure modes can be well distinguished. Then, by combining the TDDB measurements and first-principles calculations, it is found that, 1) the annealing temperature has large impacts on the initial defects concentrations while weakly affect the trap generation rate; 2) the breakdown paths take place mainly in the amorphous regions, which could generate reconfigurable filaments and cause RRAM properties; 3) temporary recovered ferroelectricity during cycling can be explained by considering the unstable breakdown paths generated at the grain boundary.