Effect of oxide thickness on the resistive switching performance of the Pt/HfO₂/TiO₂/Pt structure

Abstract A model of Pt/HfO 2 /TiO 2 /Pt resistive random access memory (RRAM) based on the oxygen vacancy conduction mechanism was constructed, then the resistive switching behaviors were observed using the finite element method (FEM). By varying the film thickness ratio of HfO 2 /TiO 2 , the distributions of oxygen vacancy concentration, electric field intensity, and temperature distributions during reset and set processes were obtained. It was found that when the thickness ratio of HfO 2 /TiO 2 is 28 nm/12 nm, the device exhibited relatively lower power consumption, reset voltage, and set voltage while maintaining the highest stability compared to other combinations of thickness. Subsequent studies on the device conduction mechanism showed that the main conduction mechanism of the Pt/HfO 2 /TiO 2 /Pt device in the low resistance state and high resistance state is the ohmic conduction mechanism and the space charge limited conduction mechanism. These findings provide valuable insights for improving the performance of the stacked RRAM devices.