Time-Dependent Dielectric Breakdown of -Doped High- /Metal Gate Stacked NMOSFETs

Time-dependent dielectric breakdown (TDDB) characteristics of La2O3-doped high-k dielectric in Hf-based high-k/TaN metal gate stack were studied. Unlike the abrupt breakdown in the conventional SiO2 , dielectric breakdown behaviors of La-incorporated HfON and HfSiON dielectrics show progressive breakdown characteristics. Moreover, the extracted Weibull slope beta of breakdown distribution is in the range of 0.87-1.19, and it is independent on capacitor areas and stress conditions. Moreover, field dependence of TBD and stress-induced leakage current strongly suggest that the E-model is more applicable to explain in TDDB of La-incorporated high-k dielectric in Hf-based high-k/metal gate stack structure.