Isotropic and anisotropic scaling analysis of nanowire phase change memory

We recently investigated the isotropic scaling properties of nanowire (NW) phase change memory (PCM) [1]. In this paper, we extend our analysis also to anisotropic scaling. By combining electrothermal theory, thermodynamic physics, and numerical simulation, the analysis explains the superiority of NW PCM over conventional thin film PCM, and reveals the different scaling properties of the three widely used operation schemes (constant electric field, constant voltage, and constant current) of NW PCM. It is demonstrated that if the device is isotropically downscaled by a factor of 1/k (k >;1), the device operation energy (current) will be decreased by k³ (k) times, and the device operation speed will be increased by k² times. The impacts of NW radius and length on PCM device performance are analyzed. Based on the analysis results, the suggestions to optimize the NW PCM device design are given.