Temperature- and time-dependent conduction controlled by activation energy in PCM

A deep insight in the conduction processes in phase-change memory (PCM) devices is needed for a reliable size scaling of the technology. In this paper we discuss and model the temperature and time dependences of the programmed cell resistance. The non-Arrhenius behavior of the resistance is interpreted by temperature-dependent current localization in the frame of the distributed Poole-Frenkel model. Experimental evidence is shown for current noise and drift being dictated by changes of the activation energy for hopping conduction. Models for current noise and drift are developed and used for projections as a function of the PCM technology node.