A comparative study on atomic layer deposited oxide film morphology and their electrical breakdown

Transition metal oxide films HfO2, ZrO2, Ta2O5, TiO2, Nb2O5, and Y2O3, together with Al2O3 and SiO2 for reference, were deposited by atomic layer deposition (ALD) and investigated. For all the films ALD process was performed within the same reactor at two temperature ranges 100–125∘C and 250–300∘C. Both water and ozone were used as oxygen sources if processes were available. Most films are amorphous as-deposited, but HfO2, ZrO2, and Y2O3 can be crystalline, depending on deposition temperature and oxygen source.