An Analytic Model of Electrochemical Metallization Memristor With a Cluster Spontaneous Decay

Abstract

An important requirement for memristor applications in functional circuits is a predictable analysis model to capture the resistance switching and synaptic behaviors. Although several memristor models based on the electrochemical metallization (ECM) mechanism have been proposed, they do not match the actual memristor with a “memory forgetting” property caused by the spontaneous decay of metal clusters in the conductive channel. Therefore, an analytic model is developed for the memristor based on the ion drift and the cluster decay. The vertical and lateral dynamics of conductive region are described by two internal state variables, i.e., the length and the diameter. It is verified that the model with the decay effect fits well with the actual device by reproducing the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> characteristic and the synaptic function. This model reveals that synaptic weight depends on the interval, amplitude, and duration of applied pulses. The effects of several key parameters on conductive decay and resistance switching are discussed here. The model can work in a hard-switching mode. This article describes some potential applications in electronic schemes using the model.