A 1S1R Model with the Monte Carlo Function for Subthreshold Sensing Operation

3-D cross-point Phase change memory (PCM) is one of the most promising next-generation nonvolatile memory for storage-class memories, and the subthreshold sensing strategy can effectively improve its limited endurance. For the first time, we propose a one-selector-one-resistor (1S1R) model with Monte Carlo (MC) function. Based on this model, we analyze the device/array/circuit parameters setting requirements for subthreshold sensing. The bit line voltage and the array should be less than 2.96V and 2k, respectively. The sensing time of the 512b array should be longer than 220ns. A large selected cell current (Icell) difference is always accompanied by a large leakage current (Ileak) difference, which severely limits array size. The bias voltage (Vbias) adjustment scheme could increase the array size, but also the power consumption. The leakage current compensation scheme should adjust the compensation current dynamically as the variation of Icell is large.