A Valid Experimental Design of the Lifetime Prediction for NAND Cell Oxide

Predicting the wear-out lifetime of memory cells is one of the most important task in the reliability of NAND flash memory. Since the lifetime is inversely proportional to the stress voltage across the cell-oxide layer during repeated program-erase cycles, in order to accurately estimate the lifetime, it is critical to calculate the exact acceleration factor for each test. This paper introduces a precise lifetime-estimation method based on the analysis of the energy-band behavior caused by the electric field during program-erase cycles. The experimental results show that the predicted result with 99% accuracy when the proposed method was applied to the wafer of the mass-produced product.