Nonvolatile Ferroelectric LiNbO₃ Domain Wall Crossbar Memory

Abstract

High-density domain wall memory based on crossbar architecture is a strong contender among next-generation high performance versatile memories due to its ultra-fast operation speed and excellent size scalability. Herein, we report 4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 4 domain wall crossbar memory arrays fabricated on a LiNbO3 single crystal. Reversible creation and erasure of conducting domain walls between two antiparallel/parallel domains at bipolar write voltages enable the storage of digital “0” and “1” information. At the crosspoint of each word and bit lines, the memory cell can be accurately accessed, programmed and erased. The diode-like rectification of readout currents exhibited by all memory cells can inhibit read and write crosstalk. The electrical testing results in the crossbar memory array demonstrated the good stability of on/off currents and good uniformity of operating voltages, which can be reflected by the fact that the distribution of the coercive voltages is within 2.9 V and the “on”/ “off” current ratio is around 100 at a reading voltage of 3 V. Good data retention and fatigue resistance are also exhibited, making it possible to integrate domain wall random access memories in high density and reliability.