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

A bipolar resistive switching memory device using high-kappa Al2O3/WOx bilayer dielectrics in an IrOx/Al2O3/WOx/W structure with a small device area of 8 x 8 mu m(2) is investigated for the first time. A high hole trapping density of similar to 1.76 x 10(18) cm(-3) in a high-kappa 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-kappa 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 0.7mW and a low current compliance of 500 mu A has a reasonable SET/RESET voltage of -1.4 V/+ 1.0 V, a high resistance ratio of > 10(3), an excellent read endurance of > 10(5) times at a large read voltage of -0.5 V, and 10 years of data retention at 85 degrees C. (C) 2011 The Japan Society of Applied Physics