Impact of scaling on thermoelectric heating process in the reset operation of phase-change memory cells

Abstract

The scaling effect on the thermoelectric heating process in phase-change memory (PCM) cells is computationally investigated through a three-dimensional finite-element simulation of the reset operation on Ge2Sb2Te5 (GST) mushroom cells. Both isotropic and non-isotropic scaling are considered. Thomson heat within GST and Peltier heat at the electrode-GST interface are separately analyzed through the captured thermal profiles within PCM cells. The results of this study indicated that the influence of Peltier heat became weaker with the cell size decreasing mainly due to a larger heat loss via the electrodes, and the steeper thermal gradients within the GST layer sustained the contribution of Thomson heat. The thermoelectric heat can be enhanced by modifying the Seebeck coefficient and the thermal conductivity of materials. Our model provides useful insights of the impact of cell scaling on thermoelectric effects, which are critical parts of effective cell engineering.