Post deposition annealing of Hf aluminate films on Si investigated by ion backscattering and nuclear reaction analyses

Layered Al2O3/HfO2 structures were deposited on Si by atomic layer deposition and the atomic transport during rapid thermal annealing was investigated by low energy ion scattering, medium energy ion scattering and narrow nuclear resonant reaction profiling. The structures were dissociated during annealing by different mechanisms, such as interdiffusion of the layers and metal loss from the dielectric. The possible detrimental effects on device electrical properties of the observed decomposition are discussed. © 2008 Elsevier B.V. All rights reserved.