Tunable Work-Function Engineering of TiC–TiN Compound by Atomic Layer Deposition for Metal Gate Applications

In this paper, we present the impact of the atomic layer deposition of carbon-containing TiN films (TiC–TiN) on the effective work function of metal-oxide-semiconductor devices. By adjusting the deposition temperature of TiC–TiN, the carbon content, which is dependent on the deposition mode, could be altered. Hence, the work function of TiC–TiN as a metal gate material could be tuned. The results revealed that the bonding concentration of Ti–C increases at higher deposition temperatures, whereas the work function of the TiC–TiN metal gate decreases from 5.0 to 4.6 eV. A high work function (5.0 eV) metal gate is suitable for a p-field effect transistor (FET) application and the midgap work function (4.6 eV) is suitable for a fully depleted silicon-on-insulator FET.