High-κ Al2O3/WOxBilayer Dielectrics for Low-Power Resistive Switching Memory Applications

Abstract

A bipolar resistive switching memory device using high-κ Al2O3/WOx bilayer dielectrics in an IrOx/Al2O3/WOx/W structure with a small device area of 8 ×8 µm2 is investigated for the first time. A high hole trapping density of ∼1.76 ×1018 cm-3 in a high-κ Al2O3 film with a thickness of 5 nm is investigated using IrOx/Al2O3/SiO2/p-Si capacitors. The thickness and chemical bonding of the high-κ Al2O3/WOx films in a resistive memory device are investigated by both high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The resistive switching memory device with a low power operation of 0.7 mW and a low current compliance of 500 µA has a reasonable SET/RESET voltage of -1.4 V/+1.0 V, a high resistance ratio of >103, an excellent read endurance of >105 times at a large read voltage of -0.5 V, and 10 years of data retention at 85 °C.