A scaling methodology for oxide-nitride-oxide interpoly dielectric for EPROM applications

This scaling scheme is based on a charge retention model which successfully explains the observed charge loss phenomena of an advanced erasable programmable read-only memory (EPROM) cell with an oxide-nitride-oxide (ONO) film as the interpoly dielectric. It is shown that there are three distinct phases in EPROM charge retention characteristics. The main sources of charge loss are charge movement in the nitride and charge leakage out of the ONO film. The charge loss can be dramatically reduced by thinning the nitride and thickening the top and bottom oxides. The resultant interpoly ONO film shows much smaller current leakage and superior charge retention capability.<
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