Simulation of TaOX-RRAM with Ta2O5−X/TaO2−X stack engineering

An atomistic Monte-Carlo simulator of TaO_X-based resistive random access memory (RRAM) with bi-layered Ta₂O_5-X/TaO_2-X stack is developed by considering generation/recombination (G-R) of oxygen vacancies (V_O) with oxygen ions (O^2-), phase transition (P-T) between Ta₂O₅ and TaO₂ as well as interactions of Ta₂O_5-X/TaO_2-X stack. The stack induced effects involving changeable Schottky barrier (SB) at the stack interface, the evolutions of O^2- and lattice oxygen (LO) in the stack and the self-compliance effect are also included in the simulator. Using the simulation tool, the resistive switching (RS) characteristics of the bi-layered TaO_X-based RRAM can be reproduced. The impacts of different stack thicknesses, oxygen contents and capabilities to take redox reactions with O^2- of TaO_2-X layer on RS behaviors are simulated. The simulation results can be utilized to achieve controllable switching processes and optimized device performances.