Observation and modelling of homogenous nucleation in Ge₂Sb₂Te₅ mushroom cells during SET operation

Phase change memory devices are used in applications for neuromorphic computing as artificial synapses. However, the cycle-to-cycle variability of the partial SET operations, likely associated with the inherently stochastic nature of the nucleation process, limits their performance. This work documents the homogeneous nucleation process occurring in scaled Ge2Sb2Te5 mushroom cells by transmission electron microscopy. The experimental data have been reproduced by a finite element model allowing for the extraction of the nucleation rates of Ge2Sb2Te5.