NBTI reliability of Ni FUSI/HfSiON gates: Effect of silicide phase

Abstract

In this work, we investigate the negative bias temperature instability (NBTI), when Ni-rich (Ni 2Si and Ni 31Si 12) silicides are used as gate electrodes on HfSiON and compare them to Ni mono-silicide (NiSi). The study also investigates the influence of increased pre-metal deposition (PMD) temperature and decreased silicide thickness on NBTI. Our study demonstrates that, when initial threshold voltage differences are taken into account and comparisons are performed at the same oxide electric field, no significant differences in intrinsic NBTI behavior are found for devices with different Ni silicide gate electrodes. In addition, we performed an Arrhenius study showing similar activation energies, indicating that no favorable conditions for dielectric degradation are created by the increased amount of Ni.