Multi-level Threshold Switching and Crystallization Characteristics of Nitrogen Alloyed GaSb for Phase Change Memory Application

Multi-level switching memristor devices are becoming a need of the hour to implement the synaptic behaviour for brain-inspired in-memory computing. In that regard, out of all the available memory candidates, Phase Change Memory (PCM) is an attractive option as it is technologically mature, and its physical mechanism is well understood. However, the current generation of PCM materials suffers from stochasticity in their multi-level switching. In this communication, nitrogen alloyed GaSb (N-GaSb) material is proposed as a multi-level switching PCM material to redress stochasticity. Interestingly, N-GaSb exhibits well-defined three states, and it is found to reduce the threshold switching power of GaSb from 16 mW to 17.2 μW. The reason behind multi-level switching and the reduction in required power for threshold switching in N-GaSb has been revealed by synchrotron-based grazing-incidence X-ray diffraction and photoelectron spectroscopy.