Thermal strain imaging of chalcogenide in a phase change memory

Thermal strain imaging using a scanning probe microscope enables us to observe thermal distribution with high resolution. A phase change memory (PCM) based on chalcogenide glasses switches their two stable states having low and relatively high resistances by Joule heating. Images obtained by thermal strain imaging revealed that Joule heating was mainly generated in particular regions and some boundaries. The large fluctuation of increases in temperature in the active area should greatly affect phase change in PCM.