Current students

Phase change memory (PCM) has gained momentum in the last 5 years as embedded nonvolatile memory (eNVM) for applications in microcontroller unit (MCU) and system-on-chip (SoC) in general. To reach this goal, materials engineering has been an essential step enabling to attain the highly demanding reliability requirements of eNVM, such as data retention at elevated temperature and soldering reflow. In particular, Ge-rich GeSbTe has become the material of choice for embedded PCM, allowing to significantly increase the crystallization point. On the other hand, Ge-rich GST shows drawbacks of set-state drift and inhomogeneous virgin state, which can be normalized by forming. Drift and forming can be managed by appropriate algorithms, however a detailed understanding of the device before forming (in the virgin state) and after forming are essential. Modeling of the physical phenomena involved in the programming of the PCM cells is fundamental for comprehending the device behavior and being able to predict possible failure points as well to control the scaling process of the devices.