RETENTION CHARACTERISTICS OF MONOS NONVOLATILE MEMORIES

摘要

Retention characteristics with various temperature and programming conditions were extensively evaluated. As a result, the decay of the threshold voltage in MONOS transistors is accurately predicted using our model, enabling the lifetime to be determined. The distribution of trapped charges just after programming and after ten years was also found. The trapped charges seemed to be rectangularly distributed just after programming. The distance from the interface, between the tunnel-oxide and silicon-nitride films, to the edge of the charge distribution in the silicon-nitride film increases as the programming voltage increases, but the concentration of trapped-charges in (he silicon-nitride film does not increase. Based on these results, we propose a new structure for MONOS nonvolatile memory transistor.