High-κ Al₂O₃/WO_x bilayer dielectrics for low-power resistive switching memory applications

A bipolar resistive switching memory device using high-κ Al ₂O₃/WO_x bilayer dielectrics in an IrO _x/Al₂O₃/WO_x/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 × 10¹⁸cm ^-3 in a high-κ Al₂O₃ film with a thickness of 5 nm is investigated using IrO_x/Al₂O ₃/SiO₂/p-Si capacitors. The thickness and chemical bonding of the high-κ Al₂O₃/WO_x 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.