Novel hafnium oxide memristor device: Switching behaviour and size effect

Unipolar RRAM devices are of high interest due to their high resistance ratio and simple selector circuit. In this paper, we report on a measurements from nano-thick memristor featuring a novel Pd/Hf/HfO2/Pd stack. The fabricated device exhibits a unipolar switching behavior, due to the asymmetric device structure and the existence of the Pd metal as a bottom electrode. The forming voltage of the proposed memristive stack (Hf-10nm/HfO2-10nm) is found to be size dependent at the microscale and its average forming voltage decreases by 20% when the active area increases from 30×30 to 1000×1000 μm2. The findings presented in this work highlight the impact of device geometry on its electrical performance and power, which provide guidance to the design tradeoffs (size, power, resistance ratio) and fabrication process of memristor devices.