Adjustable voltage dependent switching characteristics of PRAM for low voltage programming of multi-level resistances

Low voltage programming of multi-level-cell phase change random access memory (MLC PRAM) is important for future low power high density applications of PRAM devices [1]. We have characterized voltage dependent resistance switching characteristics of PRAM devices with various voltage pulses, based on which a dual-pulse programming method is systematically proposed to demonstrate some principles of low voltage MLC programming. A microstructural model is also introduced to provide a comprehensive explanation of resistance swiching for various voltage pulses.