Investigations of titanium nitride as metal gate material, elaborated by metal organic atomic layer deposition using TDMAT and NH3

This study reports for the first time, the evaluation of the work function and thermal stability of TiN gate material for deep sub-micron CMOS, elaborated by using metal organic atomic layer deposition, from TDMAT and NH3 precursors. Composition, microstructure and electrical properties of atomic layer deposited TiN films are characterized by using combined analytical techniques. The TiN films exhibit suitable properties for nMOSFET requirement with an effective work function of 4.2 eV obtained on silicon oxide and a good stability up to 1050 °C. The effective work function measured on high-k dielectric (HfO2) is found to be 4.3 eV and the stability upon high temperature annealing is less favorable.