Modeling of apparent activation energy and lifetime estimation in NAND flash memory

Misunderstanding apparent activation energy ( E aa ) can cause serious error in lifetime predictions. In this paper, the E aa is investigated for sub 20 nm NAND flash memory. In a high-temperature (HT) regime, the interface trap ( N it ) recovery mechanism has the greatest impact on the charge loss. However, the values of E aa and E a (Nit) have a wide difference. Also, the lifetime of the device cannot be estimated by the Arrhenius model due to the E aa roll-off behavior. For the first time, we reveal the origin of abnormal characteristics on E aa and derive a mathematical formula for E aa as a function of each E a (mechanism) in NAND flash memory. Using the proposed E aa equation, the accurate lifetime for the device is estimated.