Dynamic VTH Tracking for Cross-Temperature Suppression in 3D-TLC NAND Flash

The cross-temperature effect has been identified as one of the sources that limits the 3D-TLC NAND Flash reliability and performance. The physical nature of the phenomenon lies on the temperature dependency of the threshold voltage distributions that is evidenced when the memory is read at a temperature different from the one experienced during its programming. State-of-the-art solutions for mitigating the phenomenon, both at circuit and system-level, are failing to entirely cover the issues of such reliability threat. In this work we present and validate a dedicated algorithm (cross-temperature dynamic VTH tracking or CTDVT) that goes in synergy with a system like a Solid State Drive to completely suppress the cross-temperature issue.