Samsung Advanced Institute of Technology

Ovonic threshold switching (OTS) selector based on amorphous chalcogenides could be used to create 3D memory technology as a new emerging memory due to its self-selecting memory (SSM) behavior. Unfortunately, the elusive mechanism governing the memory writing operation limits their compositional and device optimization. Here, we investigate the mechanism behind the polarity-dependent threshold voltage shift (ΔV_TH) by combining the theoretical and experimental analysis. By examining the physical principles of threshold switching and defect state analysis, it is validated that the ΔV_TH as a memory window can be attributed to the charged defects dynamics and their gradient near electrodes, influenced by the non-uniform electric field after threshold switching. This contribution provides critical insights into the operational mechanism of OTS-based SSM referred to as selector-only memory, highlighting its advantages for high-density, low-cost, and energy-efficient memory technologies in the AI era.