Ferroelectric switching and field effect of Pb(Zr0.7Ti0.3)O3 on Ba1−xLaxSnO3

Abstract

Ferroelectric field-effect transistors offer a potential for its important role in integrated memory and computing systems, and research on them is actively ongoing. In this study, we investigated the ferroelectric properties of $\mathrm{Pb}\left(\mathrm{Z}{\mathrm{r}}_{0.7}\mathrm{T}{\mathrm{i}}_{0.3}\right){\mathrm{O}}_3$, which is lattice matched with the La-doped high mobility perovskite oxide semiconductor $\mathrm{B}{\mathrm{a}}_{1-x}\mathrm{L}{\mathrm{a}}_x\mathrm{Sn}{\mathrm{O}}_3$. Growth of the $r$ phase in epitaxial $\mathrm{Pb}\left(\mathrm{Z}{\mathrm{r}}_{0.7}\mathrm{T}{\mathrm{i}}_{0.3}\right){\mathrm{O}}_3$ on $\mathrm{B}{\mathrm{a}}_{1-x}\mathrm{L}{\mathrm{a}}_x\mathrm{Sn}{\mathrm{O}}_3$ was confirmed and its basic ferroelectric and dielectric properties were studied by polarization-electric and capacitance-voltage measurement. We then studied the field effect of $\mathrm{Pb}\left(\mathrm{Z}{\mathrm{r}}_{0.7}\mathrm{T}{\mathrm{i}}_{0.3}\right){\mathrm{O}}_3$ on the electrical properties of $\mathrm{B}{\mathrm{a}}_{1-x}\mathrm{L}{\mathrm{a}}_x\mathrm{Sn}{\mathrm{O}}_3$ as we vary the La doping concentration. We find that the field effect of $\mathrm{Pb}\left(\mathrm{Z}{\mathrm{r}}_{0.7}\mathrm{T}{\mathrm{i}}_{0.3}\right){\mathrm{O}}_3$ on $\mathrm{B}{\mathrm{a}}_{1-x}\mathrm{L}{\mathrm{a}}_x\mathrm{Sn}{\mathrm{O}}_3$ is determined by competition between its ferroelectric and dielectric properties, depending on the La doping concentration. In high La doping rates, the field effect is dominated by the ferroelectric switching while in lower La doping rates, the effect is mainly by dielectric response as the depolarization field in the depleted layer weakens the ferroelectric effect. As per the width and direction of the hysteresis, it is also controlled by the competition between the counterclockwise ferroelectric response and the clockwise dielectric response due to the trapped charges near the interface. This study offers insights into optimizing the field effect by understanding the complex interplay between ferroelectric materials and low carrier density semiconductors.