Effects of N-Rich TiN Capping Layer on Reliability in Gate-Last High-k/Metal Gate MOSFETs

Abstract

Time-dependent dielectric breakdown (TDDB) and bias temperature instability (BTI) in gate-last technology are studied to characterize the gate-last HK/MG MOSFETs with enrichment of nitrogen inside HK/MG stack and its effects. Especially, to prevent Nitrogen-induced defect generation leading to extra NBTI degradation, it is needed that nitrogen should be mainly inside bulk HfO2 while interface layer (IL) is free from the effect of nitrogen. To explore this, N-rich TiN capping layer deposition and plasma nitridation (PN) approaches are introduced and compared.