Resistive Switching Characteristics and Reliability of SiN_x-Based Conductive Bridge Random Access Memory

The switching properties of Te and TeTiW top electrodes (TEs) on TiW/SiN/TiN resistive switching memory devices are explored in this paper. The TeTiW TE device exhibits more favorable bipolar resistive switching behavior because of the decrease in binding energy after its use. This finding is confirmed through X-ray photoelectron spectroscopy analyses. The filament of the TeTiW TE device is metal like after forming, and the reset process corresponds with the thermal-dissolution mechanism. A physical model based on a Te filament is constructed to explain such phenomena. The TeTiW TE device provides the excellent endurance of more than 10⁴ cycles, with an ON/OFF ratio of 500. The improvement can be attributed to the filament's robustness during the forming and set processes, which prevent its diffusion even at high temperature. The device also features long retention for up to 10⁴ s at 225 °C without stress, and 10⁴ s at 85 °C with stress of -0.3 V. Therefore, it has high potential for high-density nonvolatile memory applications.