Physics-Based Statistical Modeling of PCM Current Drift Including Negative-Drift-Coefficients

Current drift over time in amorphous
$(\alpha)$
chalcogenide
$(C)$
-based phase-change memory (PCM) is investigated through statistical electrical characterization of 45-nm-PCMs integrating
$\alpha{\rm Ge}_{2}{\rm Sb}_{2}{\rm Te}_{5}$
. Then a physically based analytical model that explains drift statistics as a function of observation time is presented. In particular, we address the negative-drift-coefficients (NDC) phenomenon, which we recognize as intrinsic to the
$\alpha C$
nature.