Classification of Three-Level Random Telegraph Noise and Its Application in Accurate Extraction of Trap Profiles in Oxide-Based Resistive Switching Memory

In oxide-based resistive switching memory (OxRAM), due to the existence of oxygen ions, electron-induced random telegraph noise (e-RTN) and oxygen ion-induced RTN (GR-RTN) coexist and cannot be distinguished directly from the current levels in typical two-level RTN signals. Thus, the accurate extraction of the trap location and energy level (X-T, E-T) based on the time constants from e-RTN is hindered, which impedes the further investigation of reliability. In this work, three-level RTN in TMOx-based OxRAM was investigated. GR-RTN and e-RTN were both observed and can be distinguished clearly by the comparison of the three discrete current levels. Also, especially for e-RTN, we discussed the bias dependency of time constants of the three-level e-RTN, and the vertical location and energy level of the trap corresponding to this three-level e-RTN were finally extracted. This extraction method after selecting e-RTN from all RTN signals provides a more accurate characterization result of the trap and will be helpful to the investigation of the reliability in OxRAM devices.