Estimates of EEPROM Device Lifetime

A method was developed to estimate EEPROM device life based on the consistency for breakdown charge, QBD, for constant voltage time dependent dielectric breakdown (TDDB) and constant current TDDB stress tests. Although an EEPROM works with a constant voltage, QBD for the tunnel oxide can be extracted using a constant current TDDB. Once the charge through the tunnel oxide, ΔQFG, is measured, the lower limit of the EEPROM life can be related to QBD/ΔQFG. The method is reached by erase/write cycle tests on an EEPROM.