Radiation Tolerance of Nanocrystal-Based Flash Memory Arrays Against Heavy Ion Irradiation

We present new results on heavy-ion irradiation of nanocrystal non-volatile addressable memory arrays. We show that the effects of a single ion hit are negligible on these devices due to the discrete nature of the storage sites. We estimate that, in order to observe an appreciable threshold voltage shift, at least three to four ion hits are needed. Despite several cells experiencing multiple hits they are still functional after the irradiation, showing no changes on the retention characteristics. These results highlight an outstanding improvement of the nanocrystal technology over the conventional floating gate memories in terms of radiation tolerance, which are encouraging for a potential application in radiation harsh environments.