R&D: WN Coating of TiN Electrode to Improve Reliability of PCM

Materials Science in Semiconductor Processing has published an article written by Zi-Jing Cui, State Key Laboratory of Functional Materials for Informatics, Nanotechnology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, PR China, and University of Chinese Academy of Sciences, Beijing, 100080, PR China, Dao-Lin Cai, State Key Laboratory of Functional Materials for Informatics, Nanotechnology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, PR China, Yang Li, Cheng-Xing Li, State Key Laboratory of Functional Materials for Informatics, Nanotechnology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, PR China, and University of Chinese Academy of Sciences, Beijing, 100080, PR China, and Zhi-Tang Song, State Key Laboratory of Functional Materials for Informatics, Nanotechnology Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, PR China.

Abstract: “The heating electrode contact (HEC), as the key part for collecting current and transferring heat in phase change memory (PCM), tends to be unevenly oxidized by the external SiO2 coating layer during manufacturing and fatigue, resulting in negative effects on the performance of PCM. In this paper, WN film is used as the protective layer to avoid oxidation of TiN HEC. The RESET/SET current of PCM cells is reduced because of the oxygen barrier and heat preservation effect of WN film. In the endurance test of HEC, the cycle times of TiN electrode double-coated by WN can reach 1012, which is significantly higher than the electrode double-coated by SiO2. Besides, the endurance characteristics of PCM cells with this new structure of HEC are proved to be better.“