Improved Channel Hot-Carrier Reliability in $p$ -FinFETs With Replacement Metal Gate by a Nitrogen Postdeposition Anneal Process

摘要

Channel hot-carrier (CHC) reliability in $p$-FinFET devices is studied related to the postdeposition anneal (PDA) process. Clearly reduced CHC degradation is observed with $hbox{N}_{2}$-PDA at the $V_{G} = V_{D}$ stress condition. The interface defect density degradation calculated from the subthreshold slope is similar in the reference and PDA devices. However, the pre-existing high-$k$ bulk defect is lower in the PDA-treated device as observed by the low-frequency-noise measurement. This leads to less hot/cold-carrier injection into the bulk defects at the high field under the $V_{G} = V_{D}$ condition, where a higher charge trapping component is expected than under the classical $V_{G} sim V_{D}/hbox{2}$ condition. The responsible bulk defect is pre-existing, not generated during the CHC stress as proven by the stress-induced leakage current analysis.