Design Of A Low RESET Voltage Phase Change Memory Cell And Its Electrothermal Simulation

The development of modern computer systems is more and more dependent on the storage subsystem,and the current storage subsystem is to store information by storing charge.With the shrinking of the process size,the development of the existing mainstream storage technology has become difficult,some of the storage technology meets its own physical limits.In order to solve this problem,some novel memory technologies based on non-charge memory mechanisms have been extensively studied,and they want to replace existing mainstream storage technologies and even break the existing storage pattern.Phase change memory is currently one of the most promising candidates for the next generation of nonvolatile,due to its advantages of fast data shuttling,good scalability,long endurance etc.The RESET power consumption of the phase change memory is very high,especially in the phase change memory cross-point architecture,there are serious leakage current problems.In order to reduce leakage current and power consumption,this paper proposes a new type of phase change memory cell which has low RESET voltage by adopting a wrapped electrode.The finite element method was used to simulate the electrothermal behavior of the RESET phase transition,and the temperature distribution,potential distribution and current density of the phase change layer in the new phase change memory cell and the traditional mushroom type phase change memory cell were analyzed.Using the defined critical RESET voltage,the results show that when the width of the phase change layer is 40 nm and the width of the heater is 20 nm,the new phase change memory cell can be RESET at 1.22 V,while the traditional mushroom memory cell needs at least 2.2V to be RESET.Therefore,a lower RESET voltage reduces the leakage current of storage bits in the cross-point architecture,and reduces power consumption,potentially improving the integration of the cross-point architecture.In addition,this paper also analyzes the influence of some material parameters and structural parameters on the two phase change memory cells.