The Work Function Behavior of Aluminum-Doped Titanium Carbide Grown by Atomic Layer Deposition

The effective work function (eWF) of Al-doped titanium carbide (TiAlC) metal electrodes prepared by atomic layer deposition shows a strong dependence on the underlying gate dielectrics. The eWF of TiAlC on HfO
₂
shows a low value of 4.2 eV independent of the deposition temperature and process conditions, whereas that on SiO
₂
shifted to a midgap value of 4.7 eV, and it was sensitive to the process conditions. The mechanism underlying this TiAlC work function dependence on different gate dielectrics is investigated in detail.