Threshold Voltage Shift Instability Induced by Plasma Charging Damage in MOSFETS with High-K Dielectric

摘要

We found that high-k devices are more susceptible to plasma charging, than SiO_2 devices and that the charging polarity strongly depends on plasma sources such as Ar- and Cl-based gas mixtures. Also we identified a unique charging polarity,i.e.,the Vt shift instability. High-k devices are found to exhibit the opposite charging polarity in accordance with the plasma sources, in contrast to SiO2, primarily owing to the characteristic hole/electron trapping phenomena: The direction of V_t shift itself depends on a plasma source and/or a amount of plasma charging damage.