Bipolar-switching operated phase change memory (PCM) for improved high-temperature reliability

Phase change memory (PCM) has reached the status of mature technology for stand-alone, embedded, and storage-class memory (SCM). A key requirement for these applications is stability at high temperature (T) during soldering, packaging and operation. To this aim, new materials and algorithms to improve reliability are essential. Here we demonstrate bipolar switching in PCM resulting in low-current operation and excellent high-T reliability. DC and pulsed switching characteristics are explained by ion migration in the chalcogenide layer, as supported by TEM and T-dependent studies. Excellent reliability at high T is demonstrated and explained by a physical model.