Estimates of EEPROM device lifetime

A method was developed to estimate EEPROM device life based on the consistency for breakdown charge, Q
BD
, 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, ΔQ
FG
, is measured, the lower limit of the EEPROM life can be related to Q
BD
/ΔQ
FG
. The method is reached by erase/write cycle tests on an EEPROM.