Demonstration of Threshold Switching and Bipolar Resistive Switching in Ag/SnOx/TiN Memory Device

Abstract

In this work, we observed the duality of threshold switching and non-volatile memory switching of Ag/SnOx/TiN memory devices by controlling the compliance current (CC) or pulse amplitude. The insulator thickness and chemical analysis of the device stack were confirmed by transmission electron microscope (TEM) images of the Ag/SnOx/TiN stack and X-ray photoelectron spectroscopy (XPS) of the SnOx film. The threshold switching was achieved at low CC (50 μA), showing volatile resistive switching. Optimal CC (5 mA) for bipolar resistive switching conditions with a gradual transition was also found. An unstable low-resistance state (LRS) and negative-set behavior were observed at CCs of 1 mA and 30 mA, respectively. We also demonstrated the pulse operation for volatile switching, set, reset processes, and negative-set behaviors by controlling pulse amplitude and polarity. Finally, the potentiation and depression characteristics were mimicked by multiple pulses, and MNIST pattern recognition was calculated using a neural network, including the conductance update for a hardware-based neuromorphic system.

Dynamic and Static Switching in ITO/SnOx/ITO and Its Synaptic Application

“…Unlike conventional SnO X , which demands an annealing process to achieve resistive switching (RS) characteristics, the as-deposited SnO X used in this paper showed RS characteristics. As-deposited SnO X by direct current (DC) reactive magnetron sputtering has already been verified the RS in a Ag/SnO X /ITO device by Da chen and Shi-Hua Huang, and it showed a low resistance of less than 3 kΩ and a resistance window of less than ~10 [ 13 , 14 ]. In addition, Jidong Jin et al reported that the DC-sputtered SnO X showed poor RS on the stack of an Al/SnO X /Pt device [ 15 ].…”

Effect of long chain fatty acids on the memory switching behavior of tetraindolyl derivatives

“…38 Such switching behavior where the device switches from HRS to LRS during the forward sweep and again switches from LRS to HRS during the reverse sweep at the same polarity is known as Threshold Switching (TS). [39][40][41][42][43] TS devices may be useful to resolve the sneak path problem in memory applications having crossbar array structure as a selector device. 40 Similar behavior was also observed in case of negative polarity, where threshold voltage (V Th ) was −1.636 V and holding voltage (V h ) was −1.437 V.…”

Transformed Filaments by Oxygen Plasma Treatment and Improved Resistance State

“…Those ions drift according to the direction of the electric field and determine the states of the device. The RS behavior of as-deposited SnO X formed through sputter has already been proven in the literature [ 12 , 13 , 14 , 15 , 16 ], but better RS characteristics can be achieved using DC-sputtering without the assistance of the annealing process.…”