电应力诱导的TiN/Ti/HfO2/W忆阻器损伤：电压极性和真空条件的关键作用

In this work, we investigate the damage caused by the catastrophic breakdown of the insulating layer in TiN/Ti/HfO2/W memristors when subjected to ramped voltage stress. Our analysis includes physical and compositional examinations of the damaged regions using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy. These techniques are complemented by _in situ_ SEM current-voltage (I–V) measurements performed under vacuum conditions. In particular, we explored the connection of the applied voltage polarity with the damage onset. We show that high negative voltages applied to the TiN top electrode typically result in worm-like damage patterns. This specific type of damage, along with more severe stages of degradation such as disconnection and melting, is exclusively observed for negative biases and does not occur under vacuum conditions. Conversely, under positive voltage stress, no damage is detected in the top electrode of the devices irrespective of the external