Impact of crystallization statistics on data retention for phase change memories

The stochastic nature of percolation is shown as a possible issue for retention in PCM devices, due to the occurrence of unlikely crystallization events that early decrease the device resistance. Failure time dispersions at high temperatures are measured and analyzed through a crystallization Monte Carlo model. A physical insight into nucleation and growth mechanisms is thus provided and a maximum working temperature of 105degC is extracted to guarantee, on large statistics, the 10 years data retention requirement for non volatile applications