Modeling and spectroscopy of ovonic threshold switching defects

This paper presents a two-state model for OTS defects with a field and temperature-dependent transition. Switching transients of OTS selectors are simulated and the dependence of the threshold voltage on the relaxation time is modeled. A spectroscopic technique to access the physical defect properties is developed and demonstrated on SiGeAsTe.

I. Introduction

Selector devices using Ovonic Threshold Switching (OTS) enable the operation of high density, cross-point resistive-switching random access (RRAM) arrays [1]. The mechanism of OTS is still debated [2]–[4] and in recent years, we published experimental evidence for a localized conduction behavior and proposed a conceptual model for OTS switching [5], [6]. The present paper aims at quantifying this approach with Monte Carlo simulations. As a result, a spectroscopic technique is developed that allows measuring the defect properties inside the switching cluster.