Evidence of the thermo-electric Thomson effect and influence on the program conditions and cell optimization in phase-change memory cells

Abstract

\u3cp\u3eWe present physical and electrical evidence of the Thomson thermo-electric effect in line-type phase-change memory cells. This causes a shift of the molten zone during RESET programming towards the anode contact, and as a consequence the phase change material (PCM) design at the contact area has a significant influence on the program conditions. First statistical studies showed a reduction of minimum Reset currents by ∼55% and Set voltages by ∼28% when PCM extensions around the anode are used instead of fine line contacts. This Thomson effect remains important with further cell scaling.\u3c/p\u3