Gate-Switchable BST Ferroelectric MoS2 FETs for Non-Volatile Digital Memory and Analog Memristor

To overcome the von Neumann bottleneck between memory and computing, the novel architectures with computing in-memory are paid much attention and expected to be compatible with digital logic computing and/or analog brain-inspired neuromorphic computing. Herein, by combining the Ba0.6Sr0.4TiO3 (BST) ferroelectric film and MoS2 layered semiconductor, a non-volatile memory is constructed, which deliver the gate-switchable function between the digital and analog functionality modes. The on/off ratio, subthreshold swing, and carrier mobility of MoS2/BST ferroelectric field-effect transistor (FeFET) are 4.95x10(6), 68 mV dec(-1), and 16.7 cm(2) V-1 s(-1), respectively. By a small electrical stimulation, the device demonstrates remarkable non-volatile memory properties, including robust long-term retention of approximate to 3000 s, superior endurance over 34 000 cycles, low operating energy at approximate to 0.3 pJ per spike. By a large electrical stress, it exhibits well memristive behavior and gating history dependent accumulation/diminution effect, which is attributed to the charge dynamic trapping/de-trapping activation at the MoS2/BST interface. Following the historic memory behaviors, a cryptosystem is developed with auto-generated reading log which is tamper-resistant at hardware level. Moreover, the synaptic functions are realized on the device such as the short-term potentiation/depression and gating-depending synaptic plasticity. This study shows the opportunities of multi-functionalities integration in a single FeFET device.