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

A bipolar resistive switching memory device using high-κ Al 2 O 3 /WO x bilayer dielectrics in an IrO x /Al 2 O 3 /WO x /W structure with a small device area of 8 × 8 µm 2 is investigated for the first time. A high hole trapping density of ∼1.76 × 10 18 cm -3 in a high-κ Al 2 O 3 film with a thickness of 5 nm is investigated using IrO x /Al 2 O 3 /SiO 2 /p-Si capacitors. The thickness and chemical bonding of the high-κ Al 2 O 3 /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 >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 °C.