Oxidation of ruthenium thin films using atomic oxygen

In this study, the use of atomic oxygen to oxidise ruthenium thin films is assessed. Atomic layer deposited (ALD) ruthenium thin films (~ 3 nm) were exposed to varying amounts of atomic oxygen and the results were compared to the impact of exposures to molecular oxygen. X-ray photoelectron spectroscopy studies reveal substantial oxidation of metallic ruthenium films to RuO₂ at exposures as low as ~ 10² L at 575 K when atomic oxygen was used. Higher exposures of molecular oxygen resulted in no metal oxidation highlighting the benefits of using atomic oxygen to form RuO₂. Additionally, the partial oxidation of these ruthenium films occurred at temperatures as low as 293 K (room temperature) in an atomic oxygen environment. - Highlights: • X-ray photoelectron spectroscopy study of the oxidation of Ru thin films • Oxidation of Ru thin films using atomic oxygen • Comparison between atomic oxygen and molecular oxygen treatments on Ru thin films • Fully oxidised RuO₂ thin films formed with low exposures to atomic oxygen.