On the Effect of Cell Geometry on the Amorphization Process in Phase-Change Memories

In phase change memories, the crystalline to amorphous phase transition is strongly affected by the cell geometry. In this paper, we study the amorphization process by analyzing the effects of amorphizing (RESET) pulses on the phase distribution inside the active chalcogenide portion of the memory cell. The purpose is to investigate how the shape and the volume of the amorphous cap are affected by the cell structure. In particular, the analysis is carried out considering two of the most popular cell architectures, namely, the Lance and the Pillar structures.