In-situ surface analysis during atomic layer etching of TiN by chlorine radical irradiation at low temperature and thermal desorption

Abstract The atomic-level behavior of a titanium nitride (TiN) surface under chlorine radical irradiation at − 10 °C and thermal desorption at 145 °C was studied using in situ X-ray photoelectron spectroscopy. These processes are integrated for thermal-cyclic atomic layer etching of TiN. Chlorine radicals rapidly generate volatile TiCl 4 on the TiN surface through the self-limiting formation of an intermediate species, TiN x Cl y . Subsequent heating at 145 °C removes TiCl 4 , whereas the intermediate TiN x Cl y remains on the surface. Controlling the self-limitation and selective removal is essential for evaluating the removal of TiN x Cl y .