A SCALING METHODOLOGY FOR OXIDE NITRIDE OXIDE INTERPOLY DIELECTRIC FOR EPROM APPLICATIONS

A novel scaling methodology of oxide-nitride-oxide (ONO) interpoly stacked dielectric has been developed and verified for advanced EPROM technology. This scaling scheme is based on a charge retention model which successfully explains the observed charge loss phenomena of an advanced EPROM cell with an ONO film as the interpoly dielectric. It will be demonstrated 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. © 1990 IEEE