Abstract: A 2D technology model of switch diode in phase change memory is designed according to the 0. 13um CMOS technology.The numerical simulation is used.After optimizing the critical parameters,a diode which structure is P +/N -/N +,can supply the 1mA RESET current at lower voltage and is able to afford 11V reverse voltage is developed.At the end of this paper,we discuss the performance of switch diode that is scaled down from 0.13um to 22nm.The simulation results show these diodes are satisfied with the RESET current at lower voltage.