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• AC-based operando laser-based photoemission electron microscopy (laser-PEEM) is proposed as a non-destructive analysis method for ferroelectric memory devices. • We implemented a Sawyer-Tower circuit into the laser-PEEM system to measure polarization–voltage hysteresis loops. • For a HfO 2 -based ferroelectric capacitor, a conduction filament formed after dielectric breakdown was successfully visualized through the top electrode of TiN. • Polarization contrast was observed through the top electrode of oxide semiconductor InZnO x . 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 Hf 0.5 Zr 0.5 O 2 (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 (InZnO x ). 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.
Fujiwara et al. (Mon,) studied this question.