Efficient Data Recovery Technique for 3D TLC NAND Flash Memory based on WL Interference

When data errors exceed ECC correction capability due to severe retention process, the data recovery technique which reduces retention errors by recharging cells is required to recover the retention-failed data. In this paper, we propose an efficient data recovery technique based on WL interference (WI). Invalid pages are utilized to apply the WI effect on retention-failed cells. The proposed technique applies different amount of WI effect to the cells according to their Vth states. Experiment results show that the proposed WI technique recovers retention-failed pages up to 15.49x faster than the state-of-the-art VSRP technique. For data recovery capability, the proposed WI technique outperforms the VSRP technique by up to 2.27x. The proposed WI technique is the first data recovery technique that can serve as a real-time solution for flash-based storage system.