Interfacial self cleaning during atomic layer deposition and annealingof HfO 2 films on native (100)-GaAs substrates

The reduction in native oxides on GaAs surface during atomic layer deposition (ALD) of HfO 2 using tetrakis-dimethylamino-hafnium precursor was investigated using x-ray photoelectron spectroscopy. The role of the ALD growth temperature on the reaction between surface oxides and precursor was studied. Interfacial oxide reduction was found to be insignificant for ALD at 200 ° C , while nearly complete for growth at 300 ° C . During postdeposition annealing at 400 ° C , any arsenic oxides present were found to decompose, resulting in an increase in the interfacial gallium oxides. Thus, control of the ALD process plays a large role in determining interface properties.