R&D: Analysis of HBM Failure in 3D NAND Flash

Electronics has published an article written by Biruo Song, Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, China, University of Chinese Academy of Sciences, Beijing 100049, China, and Yangtze Memory Technologies Co., Ltd., Wuhan 430205, China, Zhiguo Li, Xin Wang, Xiang Fu, Yangtze Memory Technologies Co., Ltd., Wuhan 430205, China, Fei Liu, Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, China, Lei Jin^, and Zongliang Huo, Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, China, University of Chinese Academy of Sciences, Beijing 100049, China, and Yangtze Memory Technologies Co., Ltd., Wuhan 430205, China.

Abstract: “Electrostatic discharge (ESD) events are the main factors impacting the reliability of NAND Flash memory. The behavior of human body model (HBM) failure and the corresponding physical mechanism of 3D NAND Flash memory are investigated in this paper. A catastrophic burn-out failure during HBM zapping is first presented. Analysis shows that NMOS fingers’ local heating induced by inhomogeneous substrate resistance R_sub and local heating induced by the drain contact and 3D stacked IC (SIC) structure lead to the failure. Therefore, a new approach is proposed to reduce local heat generation. Finally, by increasing N+ length (NPL) and introducing a novel contact strip, the silicon result shows enhanced ESD robustness.“