Abstract
Ferroelectric-gate field-effect-transistors (FETs) have been investigated for the applications to nonvolatile memory devices. We have proposed YMnO3/Y2O3/Si structure for Metal/ Ferroelectric/Insulator/Semiconductor (MFIS) type ferroelectric gate FET, because YMnO3 has suitable properties for this application such as small spontaneous polarization and low permittivity. Moreover, we have proposed several characterization methods such as pulsed C-V measurement, polarization-electric field (P-E) measurement for MFIS capacitors. In this study, electrical properties of epitaxially grown Pt/ YMnO3/Y2O3/Si capacitors were characterized by the methods described above as well as conventional C-V measurement to discuss the ferroelectric characteristics, optimum structure and the effect of space charge on the electrical properties. The leakage current mechanisms and the effect of the leakage current on the memory retention characteristics are also discussed.
