Sub-20-nm DRAM Technology under Negative Bias Temperature Instability (NBTI): from Characterization to Physical Origin Identification

This paper studies the negative bias temperature instability (NBTI) starting with 100 ns in sub-20-nm DRAM technology for the first time. Ultra-fast electron traps were isolated by the time-voltage swept charge pumping technique. Distinct types of slow traps were separated using the discharging-based multi-pulse technique. Considering the non-radiative multi-phonon theory, we precisely obtained the spatial and energy distribution of various traps and, through comparison with ab-initio calculations, revealed that these traps originate from nitrogen substitution, oxygen vacancies, and nitrogen interstitial. The results contribute to a deeper understanding of the reliability of DRAM devices.