Phase change memory cell using tungsten trioxide bottom heating layer

Phase change memory (PCM) cell with tungsten trioxide (WO3) bottom heating layer is investigated. The crystalline WO3 heating layer promotes the temperature rise in Ge2Sb2Te5 layer that causes the reduction in reset voltage compared to a conventional PCM cell. The theoretical thermal simulation and calculation for reset process are applied to understand the thermal effect of WO3 heating layer. The improvement in thermal efficiency of PCM cell originates from the low electrical resistivity and low thermal conductivity of crystalline WO3 material.