Ferroelectric properties of c-oriented YMnO3 films deposited on Si substrates

Abstract

We have proposed the use of ${\mathrm{RMnO}}_{\mathrm{3}}$ (R: rare earth elements) films for metal–ferroelectric–semiconductor field effect transistor (MFSFET)-type ferroelectric random access memories (ferroelectric RAMs). This reports the production of ${\mathrm{YMnO}}_{\mathrm{3}}$ films on Si substrates for MFSFET with confirmation of the distinct ferroelectricity by $\mathrm{P–E}$ hysteresis and capacitance–voltage $\mathrm{(C–V)}$ measurement. (0001)-oriented ${\mathrm{YMnO}}_{\mathrm{3}}$ films were obtained on a (111)Si substrate using a pulsed-laser deposition method. Although the ${\mathrm{Pt/YMnO}}_{\mathrm{3}}\mathrm{/Si}$ structure exhibits a very small remnant polarization of $\text{1.2\hspace{0.17em}}{\mathrm{nC/cm}}^{\mathrm{2}},$ it has clear ferroelectric polarization switching type $\mathrm{C–V}$ characteristics with a memory window of 1.1 V. The dielectric constant and the dissipation factor were 27.8 and 0.035, respectively. The polarization switching characteristics are discussed.