Charge retention of MNOS devices limited by Frenkel-Poole detrapping

A simple analytical expression is derived for charge retention in MNOS memory devices assuming that retention loss is limited by Frenkel-Poole release from monoenergetic traps. This model shows that charge retention becomes eventually independent of the initial charge distribution. Experimental data obtained at elevated temperatures confirm this model and provide a trap depth of 1.5 eV, Frenkel-Poole coefficient of about 6×10−4 cm1/2 V−1/2 eV, and effective escape attempt rate factor of 1.2×108 sec−1.