A Novel Ferroelectric MemCapacitor Enabling Multilevel Operation

Abstract

The progress of biologically inspired neuromorphic computing hardware in the last decade has been fostered also by the advancement in CMOS-compatible memristors, providing a nonvolatile storage of multiconductance states mimicking the synaptic weights in biological systems. This article is instead focused on the less-explored field of memcapacitors (MemCaps), which only very recently has attracted a renewed interest, and it is based on devices capable of tuning their capacitance. In particular, we present by means of extensive numerical simulations carefully calibrated against experimental data the operation of a two-terminal ferroelectric MemCap exhibiting multilevel, polarization-dependent capacitance values. The MemCap exploits a ferroelectric gated-diode structure, and it is thus fully compatible with CMOS processing. Our results show that multilevel operation is viable using properly shaped pulse trains at the gate terminal, and moreover, a nondestructive readout can be achieved by means of small-amplitude ac signals.