Sub 20 nm‐Node LiNbO₃ Domain‐Wall Memory

Abstract Conducting domain walls (DWs) induced by an in‐plane electric field applied to a mesa‐like cell fabricated at the surface of an insulating LiNbO₃ single‐crystal film play a key role in the diode‐like DW memory. However, the lateral shrinking of the cell size below a 20 nm‐node technology becomes challenging due to the presence of interfacial layers with the finite thickness above 30 nm. In this work, 15 nm‐sized LiNbO₃ cells are fabricated in high on/off current ratio of ≈10² on the SiO₂/Si wafers immune to the interfacial‐layer effect, which can be operated below 5 V and also promising to meet the CMOS processing. It is found that the interfacial‐layer thickness reduces almost linearly with the shrinking cell size from 100 to 15 nm and the DW current increases by 25 times. The retention time of written information at +/−3 V is over 48 h, the domain switching time can approach 5 ns at 4 V in high switching endurance (≈10⁹ cycles). These achievements imply the high storage density of a ferroelectric DW memory without the fundamental interfacial‐layer limit.