Reconfigurable Quasi-Nonvolatile Memory/Subthermionic FET Functions in Ferroelectric-2D Semiconductor vdW Architectures.

The functional reconfiguration of transistors and memory in homogenous ferroelectric devices offers significant opportunities for implementing the concepts of in-memory computing and logic-memory monolithic integration. Thus far, reconfiguration is realized through programmable doping profiles in the semiconductor channel using multiple-gate operation. This complex device architecture limits further scaling to match the overall chip requirements. Here, reconfigurable memory/transistor functionalities in a ferroelectric-gated van der Waals transistor by controlling the behavior of ferroelectric oxygen vacancies at the interface are demonstrated. Short- and long-term memory functions are demonstrated by modulating the border oxygen vacancy distribution and the associated charge dynamics. The quasi-nonvolatile long-term memory exhibits data retention of over 105 s and endurance of up to 5 × 105 cycles, verifying its applicability as a potential device platform for neuromorphic networks. More importantly, by modulating the ferroelectricity of the interfacial domains with the interactions of oxygen vacancies, a hysteresis-free logic transistor is realized with a subthermionic subthreshold swing down to 46 mV dec-1 , which resembles a negative-capacitance field-effect transistor. The new concept of achieving functional reconfiguration with prior device performance in a single-gate ferroelectric field-effect transistor is of great advantage in future integrated circuit applications.