Fabrication and characterization of ferroelectric gate piezoelectric-semiconductor thin-film transistors using a ZnO/YMnO₃ hetero structure

Abstract

We have proposed ferroelectric gate piezoelectric-semiconductor thin-film transistors (TFTs) as a novel non-volatile logic device. It can be expected that the spontaneous polarization and piezoelectricity of the piezoelectric semiconductor and ferroelectric layers enhance the carrier confinement at the ferroelectric/piezoelectric semiconductor interface. In this study, ZnO and YMnO₃ were selected as a channel layer and a ferroelectric gate insulator, respectively. The Au/Ti/ZnO/YMnO₃/Pt/sapphire epitaxial capacitor exhibited a ferroelectric-type C-V hysteresis. Furthermore, the ferroelectric gate TFT using a ZnO/YMnO₃ hetero structure exhibited the on/off ratio of more than 10³ and a ferroelectric-type hysteresis with a memory window of 1.1V in the I_D-V_G measurement.