Resistive Switching Characteristics of WO<sub>3</sub>/ZrO<sub>2</sub> Structure With Forming-Free, Self-Compliance, and Submicroampere Current Operation

Abstract

The homogeneous switching of Ti/WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /W resistive switching memory devices with stable resistive switching, forming-free, self-compliance, and multilevel operation characteristics are demonstrated. The area dependence of current at the low resistance and high resistance states confirms that the switching mechanisms of the devices are homogeneous conduction. The devices exhibit the stable bipolar resistive switching behavior with a low operating current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&lt; 10^{-6}$ </tex-math></inline-formula> A) by inserting the WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> layer with high electron affinity between the Ti top electrode and the ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layer and modulating the potential profiles at the WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interface. In addition, multilevel operation can be achieved by adjusting the magnitudes of set/ reset voltages.