Bipolar resistive switching characteristics of atomic layer deposited Nb_2O_5 thin films for nonvolatile memory application

摘要

Resistive switching behavior of Nb_2O_5 prepared by atomic layer deposition was investigated as a promising candidate for next generation nonvolatile memory technology. The crystalline structure of deposited film at 300 °C was found to be polycrystalline by X-ray diffraction (XRD) and the film was estimated to be oxygen deficient by X-ray photoelectron spectroscopy (XPS). The low resistance ON state and high resistance OFF state can be reversibly altered under low voltage about ±1 V. More than 1000 reproducible switching cycles by DC voltage sweep were observed with a resistance ratio above 10, which was large enough to read out for memory applications. Moreover, the HRS and LRS of the devices are stable for more than 5 × 10~4 s and does not show any degradation during the test.