Simulation-Based Comparison of Cell Design Concepts for Phase Change Random Access Memory

The RESET operation of different design concepts for phase change random access memory (PCRAM) cell is studied and compared using a three dimensional simulation model. This numerical algorithm comprises four interacting sub-models, which describe the electrical, thermal, phase change, and percolation dynamics in the PCRAM devices during the switching operation. The so-called vertical, confined, and lateral cell geometries are evaluated in terms of their current requirements for RESET operations, which is one of the most critical issues for an achievement of high integration densities. The advantages of the confined and lateral cell architecture as compared to the conventional vertical cell concept are explored, demonstrating their benefits of advanced thermal management and minimized current defined area. The simulation results agree well with experimental features of the RESET operation for the PCRAM design concepts studied.