Intrinsic data retention in nanoscaled phase-change memories - Part II: Statistical analysis and prediction of failure time

The statistical spread of intrinsic data retention times in phase-change memory (PCM) cells is studied. Based on the crystallization and percolation model described in Part 1, the crystalline grain size in the amorphous volume after data loss is extracted. From the temperature dependence of grain size, the authors calculate the statistical shape factor for the distribution of failure times, allowing a statistical prediction of data retention in PCM large arrays. The scaling and optimization issues with respect to failure time statistical spread are finally addressed.