Low-voltage nonvolatile multi-bit memory fabricated by the patterning and transferring of ferroelectric polymer film

Abstract

In ferroelectric material, polarization is defined as a volumetric density of dipole moments; therefore, macroscopically many different states of polarizations between positive remanent polarization and negative remanent polarization can be addressable. Simply by controlling the voltage range, multi-states of polarization could be possible. However, for reliable operation of such a multi-bit memory system, all individual states must be completely separated from other states such that only a certain portion of dipoles in a memory device needs to be switched at a certain state. Such a reliable operation would be achieved by spatially separating the switching area in which the individual thickness is different. In this work, it is demonstrated that reliable ferroelectric multi-bit memory could be realized by patterning and transferring ferroelectric polymer film. Also, for low-voltage operation, the highest thickness was designed as 150 nm, which enabled the multi-bit memory to operate within maximal 20 V. Furthermore, a timing diagram, retention and fatigue measurements showed that the fabricated multi-bit memory would be quite promising for emerging organic electronics.