Breakdown and polarization contrasts in ferroelectric devices observed by operando laser-based photoemission electron microscopy with the AC/DC electrical characterization system
We have developed an operando laser-based photoemission electron microscope (laser-PEEM) with a ferroelectric characterization system. A Sawyer-Tower circuit was implemented to measure the polarization-voltage (P−V) characteristics of ferroelectric devices. Using this system, we successfully obtained the well-defined P−V hysteresis loops for a ferroelectric capacitor incorporating Hf0.5Zr0.5O2 (HZO), reproducing the typical field-cycling characteristics of HZO capacitors. After dielectric breakdown caused by field-cycling stress, we visualized a conduction filament through the top electrode without any destructive processing. Additionally, we successfully observed polarization contrast through the top electrode of an oxide semiconductor (InZnOx). These results indicate that our operando laser-PEEM system is a powerful tool for visualizing conduction filaments after dielectric breakdown, the ferroelectric polarization contrasts, and electronic state distribution of materials implemented in ferroelectric devices, including ferroelectric field-effect transistors and ferroelectric tunnel junctions.
@article{arxiv.2508.07698,
title = {Breakdown and polarization contrasts in ferroelectric devices observed by operando laser-based photoemission electron microscopy with the AC/DC electrical characterization system},
author = {Hirokazu Fujiwara and Yuki Itoya and Masaharu Kobayashi and Cédric Bareille and Toshiyuki Taniuchi},
journal= {arXiv preprint arXiv:2508.07698},
year = {2025}
}