Environment and baking influence on charge retention on silicon nitride charge trap layers.

We report the charge storage capacity of silicon nitride using Kelvin force microscopy (KFM). KFM is performed under various environments and for different thicknesses of Si3N4 (3 nm, 6 nm, and 9 nm) on top of a 10-nm SiO2 blocking oxide. We prove increased storage capacity with increased thickness and strong localization of charge characteristics - under reduced surface contamination. We have found that surface contamination is here linked with baking and presence of nitrogen flux. The structure shows strong retention under ultra high vacuum and Si3N4 thickness dependency. The total charge stored in each of these structures is calculated using Poisson solver. [ABSTRACT FROM AUTHOR]