Anomalous low temperature charge leakage mechanism in ULSI flash memories

We present a systematic study of an anomalous charge leakage phenomenon in flash memories which occurs at temperatures below 150/spl deg/C. Essential characteristics of the leakage are described in association with various process parameters. A new leakage mechanism based on diffusion of an ionic entity produced by regenerative electrochemical reactions through percolating networks in the silicon dioxide is proposed.