Enhanced memory characteristics by interface modification of ferroelectric LiNbO3 films on Si using ZnO buffers

Abstract

Interface modification of ferroelectric LiNbO3 (LN) films on silicon (Si) is performed by the incorporation of a ZnO buffer layer. The microstructures and memory characteristics of the heterojunctions are characterized. Single c-axis LN films are promoted on Si (100) substrates and interfacial reaction is prevented by the nanoscale modification. Due to the ferroelectric polarizations of the LN films, clockwise capacitance–voltage memory windows can be observed clearly even at lower sweep voltages than 5V. The size of the window increases to a saturation value of ∼1.8V with applied voltage and no obvious charge injection happens in the whole sweeping voltage range. After 105s and 105 cycles, both the high and low capacitance values show no obvious degradation and the heterojunction exhibits good retention properties. Therefore, the present work supplies an effective route to improve the interface of LN/Si heterojunction and develop high-performance nonvolatile ferroelectric memory devices.