Atomic layer deposition growth of high-κ dielectric films (ZrO2 and HfO2) was performed by using ZrCl4, HfCl4, and H2O as precursors. Time-of-flight secondary ion mass spectrometry was used here to investigate the Cl distribution in atomic layer deposition grown ZrO2 and HfO2 films, and its evolution during rapid thermal processes in a N atmosphere. The out-diffusion of Cl was found to depend strongly upon the annealing temperature and weakly upon the annealing time. In ZrO2, the Cl concentration was already significantly decreased at 900C. In HfO2, it was extremely stable; even at 1050C.

Chlorine Mobility during Annealing in N2 in ZrO2 and HfO2 Films Grown by Atomic Layer Deposition. S.Ferrari, G.Scarel, C.Wiemer, M.Fanciulli: Journal of Applied Physics, 2002, 92[12], 7675-7