Improved SPICE macromodel of phase change random access memory

This paper presents an improved SPICE macromodel of phase change random access memory (PCRAM). Based on the circuit-based model architecture in [1], the novelty of this work lies in (1) accurate modeling the current-voltage (I-V) plot including the snapback phenomenon, and (2) solution to the falling edge problem to avoid misrepresentation of the PCRAM state, and (3) calibration of the crystallization time for potential multilevel (ML) operation of the PCRAM.