Statistical analysis of nanocrystal memory reliability

This work presents a statistical analysis of nanocrystal (NC) memory reliability. Characterization of data retention for 256 Kbit arrays after high-field stress provides evidence for an anomalous tail of one-few leaky cells. The statistical impact of the anomalous tail (about 10^-6-10^-5) is shown to be largely reduced as compared to conventional Flash arrays with continuous floating gate. The SILC immunity in our samples is discussed based on discrete-storage effects. Finally, we present a new Monte Carlo model for lateral tunneling in the NC network, which quantitatively accounts for the observed anomalous tail in the array.