Word line interference based data recovery technique for 3D NAND Flash

Abstract

When the NAND Flash memory is used beyond specific retention time, data stored in NAND Flash memory may not be read out correctly due to retention error. In this paper, a word line interference (WI) based data recovery technique is proposed to recover retention-failed data. By using WI, a large amount of electrons can be re-injected into retention-failed cells with one program operation. To improve recovery efficiency and recover retention error in a block, an iterated WI recovery algorithm which combines WI and previously reported DRRP technique is proposed. Experiment results show that WI recovery technique gains a higher recovery efficiency compared with DRRP technique.