Characterizing the Reliability and Threshold Voltage Shifting of 3D Charge Trap NAND Flash
Weihua Liu1,a, Fei Wu1,b, Meng Zhang1,c, Yifei Wang1,d, Zhonghai Lu2, Xiangfeng Lu3 and Changsheng Xie1,e
1Huazhong University of Science and Technology, China
aliuweihua@hust.edu.cn
bwufei@hust.edu.cn
czgmeng@hust.edu.cn
dyifeiwang@hust.edu.cn
ecs_xie@hust.edu.cn
2KTH Royal Institute of Technology, Sweden
zhonghai@kth.se
3Beijing Memblaze Technology Co., Ltd., China
xiangfeng.lu@memblaze.com
ABSTRACT
3D charge trap (CT) triple-level cell (TLC) NAND flash gradually becomes a mainstream storage component due to high storage capacity and performance, but introducing a concern about reliability. Fault tolerance and data management schemes are capable of improving reliability. Designing a more efficient solution, however, needs to understand the reliability characteristics of 3D CT TLC NAND flash. To facilitate such understanding, by exploiting a real-world testing platform, we investigate the reliability characteristics including the raw bit error rate (RBER) and the threshold voltage (Vth) shifting features after suffering from variable disturbances. We give analyses of why these characteristics exist in 3D CT TLC NAND flash. We hope these observations can guide the designers to propose high efficient solutions to the reliability problem.
Keywords: 3D NAND Flash, Charge Trap, Reliability, Threshold Voltage Shifting.
