Negative-source enhanced source-side injection achieving 100-ns cell programming in multilevel flash memories

An enhanced source-side hot-electron injection scheme for a highspeed programming of multilevel flash memories has been developed. Applying a negative voltage at the source raises hot-electron injection efficiency and cell programming improves 20 times from the conventional scheme, achieving 100-ns cell programming. We have also developed a scheme generating negative source voltage by leveraging the capacitive coupling to achieve a narrow cell-programming-speed distribution along with the high speed.