Abstract: 

We investigated the charge decay characteristics of a silicon-oxide-nitride-oxide-silicon type nonvolatile memory at elevated temperatures. Based on the amphoteric trap model and the thermal emission model of the trapped charge, we propose an advanced charge decay model which includes the effect of the bottom oxide, and apply it to extraction of the trap density distribution in energy levels of the nitride layer. The samples prepared have nitride films deposited simultaneously and are classified into two groups according to the thickness of the bottom oxide. The trap density distributions extracted from two groups showed good consistency.