The Impact of the Electrode Performance on the Endurance Properties of the Phase Change Memory Device

The cycle operation was performed on 1325 phase change memory (PCM) cells, and 4% of these cells could not be RESET to the high-resistance state after 10
⁶
cycles. The grown grains have been found in the TEM images, and the heat electron contact (HEC) has laterally diffused. The energy-dispersive X-ray spectroscopy profiles of HEC expound that Si and O elements have both multiplied. Thus, the HEC resistance has increased, resulting in insufficient RESET current. According to measurement, the HEC resistance increased from 4.6 to 7.2
$\text{K}{\Omega }$
after 10
⁶
cycles, which would decrease the RESET current from 0.7 to 0.45 mA. Compared with the endurance characteristics of the HEC and PCM device, the PCM device, with an increased HEC resistance, cannot be fully operated. When the HEC resistance is large enough to reduce the RESET current to 0.55 mA, the PCM device would be stuck to set.