R&D: Revisiting Crystallization Model of Phase Change Memory With Ab Initio Simulations

IEEE Xplore Digital Library has published, in 2019 8th International Symposium on Next Generation Electronics (ISNE) proceedings, an article written by Xuhui Chen, The Shenzhen Key Lab of Advanced Electron Device and Integration, ECE, PKUSZ,Shenzhen,,China,Lining Zhang, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, China, Xinnan Lin, The Shenzhen Key Lab of Advanced Electron Device and Integration, ECE, PKUSZ,Shenzhen,,China, and Mansun Chan, HKUST Shenzhen Research Institute, Shenzhen, China.

Abstract: “The crystallization of phase change memories (PCM) is usually described by a Johnson-Mehl-Avrami (JMA) equation in a SPICE model. In this work recent ab initio molecular dynamic simulation results are used for the JMA equation benchmark. It is found that: (a) the commonly used JMA equation does not account for the incubation period at the initial stage of phase change memory crystallization, even the equation is easily implemented with a sub-circuit. (b) the JMA equation based on the Arrhenius formula cannot reflect the crystallization rate with temperature. This paper proposes a crystallization model that can reproduce the incubation period and the crystallization rate dependence on temperature, thus improves the model accuracy.“