Scaling behavior of PCM cells in off-state conduction

A novel phase change memory (PCM) cell with Additional Top Electrode (ATE) is introduced to investigate the scaling behavior of the off-state with the dimension of amorphous state region. The electrical conduction in ultra-thin amorphous state layer is investigated. The trap spacing is one of the key parameters that govern the conduction mechanism and threshold voltage in the sub-threshold region which can be extracted by measuring the change in the activation energy of conduction with respect to the applied voltage. The linear dependence of the trap spacing on the dimension of amorphous state region is demonstrated, which could provide guidelines for designing ultra-thin film based PCM device.