Estimation method for bit upset ratio of NAND flash memory induced by heavy ion irradiation

In order to estimate the bit upset ratio of NAND flash memory induced by heavy ion irradiation, starting from the physical mechanism of the bit upset of NAND flash memory, an analytical model based on statistical methods was developed to describe the relationship between heavy ion energy deposition near the floating gate, the threshold dose distribution of the memory array, and the bit upset ratio. The heavy ion irradiation experiment on NAND flash memory was conducted to verify the effectiveness of the estimation method. The maximum deviation between the fitting result of the analytical model and the experimental result is 5.0%, and the root mean squared error is 1.2 × 10−11. The analytical model can reflect the inflection point in the single event upset cross-section, which, according to the analytical model, is caused by the different proportions of the contribution of large events and small events defined in the model to the bit upset ratio. The analytical model also reflects the characteristics of the multiple-cell upsets from the side and is consistent with experimental results.