Peculiarities of electron tunnel injection to the drain of EEPROMs

A specific time-resolved dynamic current measurement procedure is used to characterize high-field electron tunnel injection to the drain of EEPROMs. This allows the direct observation of a transient regime eventually occurring in the case of moderately doped drain. Another peculiarity is also evidenced, namely a stationary regime where measured current is far higher than anticipated by simulation. This is attributed to a non-equilibrium charge versus band-bending in the drain which is controlled by electron–hole pairs subsequent to impact ionization of electrons tunnelling from the gate.