Broad energy distribution of NBTI-induced interface states in p-MOSFETs with ultra-thin nitrided oxide

Abstract

The energy distribution of interface states during NBTI stress of ultra-thin nitrided-oxide p-FETs is studied using a combination of LV-SILC and DCIV measurements. LV-SILC is sensitive to states near the conduction band edge:, while DCIV is sensitive to states near mid-gap. The results show that die interface states associated with NBTI in nitrided oxides have a very broad energy distribution, Compared to pure SiO<inf>2</inf>, the interface state density in nitrided oxide is higher in the upper half of the Si band gap. In addition, generated bulk neutral traps show a poor agreement with the NBTI-induced threshold voltage shift.