Resistive Random Access Memory Filament Visualization and Characterization Using Photon Emission Microscopy

Near InfraRed (NIR) photon emission is observed from filaments in HfO
₂
Resistive Random Access Memories (ReRAMs). This technique is non-destructive and offers rapid localization of filaments, enabling statistical analysis of their spatial distribution. We show that the emission is electric-field driven. We also report direct experimental evidence of i) completely random spatial distribution of filaments across multiple devices and ii) formation of multiple filaments inside a single large device.