A new observation on initial charge loss in EPROM

Abstract

In this paper, a new observation on the charge loss in an EPROM is reported. We found that the charge loss characteristics in an EPROM can be divided into two phases. The first phase is dominated by the charge transport in the interpoly dielectric and the second phase by the thermionic electron emission from the floating gate. Due to the fast charge loss rate, the charge loss in the first phase governs the threshold stability of the EPROM device. Based on the relationship between the first phase charge loss and the initial programmed charges, a method to determine the programming window for better threshold voltage stability is proposed.