Résumé
Volatile memristors have been gathering a lot of attention as devices suitable for technological applications, such as neuromorphic devices and random number generators, to name a few. Their operating mechanism is a sharp and volatile resistivity variation, switching between high and low resistance states. A thorough understanding and modeling of this resistive switching are essential to fully exploiting volatile memristors. In this respect, multi-physics simulations are crucial. This is especially the case when dealing with devices fabricated with innovative materials, where both material growth and device processing are still to be completely controlled. Then, simulations allow to investigate the interplay between different material properties and/or device features that would be otherwise obscured due to the inherent variability of devices.In this work, we show results of 3D technology computer-aided design (TCAD) electrothermal simulations of volatile memristors based on vanadium dioxide (VO2). We avail of a dedicated TCAD approach [1], [2], developed to model the resistive switching of VO2 volatile memristors as induced by the Joule effect. We combine the electrothermal device simulations with SPICE circuit simulations to simulate the dynamics of VO2 oscillators. VO2 oscillators have recently attracted a large interest [3] as the main elements for realization of systems of coupled oscillators, or oscillatory neural networks (ONNs), which are circuits whose dynamics resemble that of networks of neurons in the human brain [4]. By our mixed-mode TCAD-SPICE approach, we are able to link realistically VO2 material properties to the behavior of the oscillator and the dynamics of simple ONN systems, thus being able to simulate realistically the working of ONN circuits as analogue computing engines. Our findings shed light on the coupled thermal and electrical behavior of VO2 oscillator as well as the behavior of networks of VO2 oscillators, providing some physical insights into the successful implementation of ONN technology.