Interfacial Dipole Modulation Device With SiO_X Switching Species

Abstract

In recent years, substantial research efforts have been devoted toward the development of non-volatile memory devices (NVM). In this regard, devices utilizing interfacial dipole modulation (IDM) have been considered. However, the narrow memory window of current IDM stack structures (HfO2-TiO2-SiO2) has been a major constraint. Herein, we propose a structure that exploits SiOx interfacial dipole layers, thereby overcoming the memory window limitation of conventional IDM stack structures. A memory window up to 8.05 V was achieved by using SiOx switching species together with HfO and TiO encapsulating layers owing to the bidirectional oxygen relocation process, resulting in numerous electric dipoles. Furthermore, we found that the memory window increases as the ratio of SiOX to Si2p and varies with the position of the SiOX layer, implying that the SiOx layer drives the switching mechanism. This IDM structure with an enhanced memory window can be used to develop practical NVM devices.