Atomistic Origin of RTN-like Centers Created and Annihilated by RRAM Write Processes

We examine in detail random-telegraph-like noise (RTN) generated in resistive random-access memory (ReRAM) structures as a consequence of applying programming pulses. We find that a single programming pulse can induce highly correlated RTN noise patterns, in terms of frequency and amplitude, which are replaced by a new pattern on the next programming pulse. A weaker 'repair' pulse is ineffective at reducing the RTN frequency or amplitude. Remarkably, similar patterns are seen in our atomistic simulations of ReRAM structures, which reveal occasional bursts of semiperiodic and constant amplitude current pulses. These can be traced to reversible back and forth oscillation of a set of point defects modulating the conductance of an electro-formed channel. This is the first report of sustained conductance oscillations caused by reversible configuration changes in VCM cells.