Effects of metal gate-induced strain on the performance of metal-oxide-semiconductor field effect transistors with titanium nitride gate electrode and hafnium oxide dielectric

In this letter, the authors investigate the strain induced by titanium nitride (TiN) electrode and effective work function (EWF) tuning for metal-oxide-semiconductor field effect transistors (MOSFETs). Scaling of TiN thickness was found to be effective both in increasing tensile stress on Si substrates and in lowering the EWF of metal gate n-MOSFETs. The device with 3nm TiN as a gate electrode showed favorable threshold voltage (Vth) for n-MOSFETs as well as higher channel electron mobility by 17% compared to the device with 20nm TiN film.