Unipolar resistive switching characteristics and scaling behaviors in La_2Mo_2O_9 thin films for nonvolatile memory applications

摘要

La_2Mo_2O_9 (LMO) thin films have been deposited on Pt/Ti/SiO_2/Si substrates by pulsed laser deposition and the resistive switching (RS) characteristics of the Au/LMO/Pt devices has been investigated. The Au/LMO/Pt devices show excellent unipolar RS characteristics with high resistance ratio between high resistance state and low resistance state (LRS), good endurance, and retention performances. The results of temperature dependence of resistance and x-ray photoelec-tron spectroscopy suggest that the observed RS characteristics can be explained by the formation and rupture of conducting filaments composed of oxygen vacancies. Furthermore, the plot of the reset current (I_R) as a function of the third harmonic coefficient (B_0) caused by Joule heating during the reset process shows scaling behavior with a power law of I_R ∝ B_0~(-δ). The I_R and reset power (P_R) can also be scaled to the resistance in LRS (R_0), i.e., I_R(P_R) ∝ R_0~(-α(β)). The observed scaling behaviors indicate the importance of the Joule heating for the RS characteristics of Au/LMO/Pt devices. These results demonstrate the potential application of LMO thin film in a nonvolatile memory device.