Thickness and polarity dependence of intrinsic breakdown of ultra-thin reoxidized-nitride for DRAM technology applications

This paper discusses the charge-trapping and intrinsic breakdown characteristics of ultra-thin reoxidized nitride with deep-trench capacitor structures for a range of thickness, voltages, and temperatures. Strong polarity dependence of charge-trapping and time-dependent dielectric breakdown (TDDB) is reported. For the first time, a physical model is proposed to relate the asymmetric charge injection and trapping to this intrinsic breakdown characteristic in thin reoxidized nitride. The thickness dependence of TDDB is also investigated and used for a reliability projection of the oxide equivalent thickness down to 2.9 nm.