Compositional stability of hafnium aluminates thin films deposited on Si by atomic layer deposition

We have used nuclear reaction analyses and Rutherford backscattering spectrometry to investigate quantitatively the compositional stability of hafnium aluminate thin films deposited on Si(001) by atomic layer deposition using HfCl4/H2O and Al(CH3)(3)/H2O precursors. It was found that increasing Al/Hf deposition cycles ratio leads to increasing oxygen deficiency in the as-deposited films as well as to increasing metal losses (up to similar to 15%) from the films after rapid thermal annealing at 1000 degrees C. Furthermore, isotopic substitution experiments, showed that incorporation of oxygen from the gas phase is eased in the cases where deposition conditions failed to supply enough oxygen to complete oxides stoichiometry. (c) 2005 American Institute of Physics.