Plasma Corrosion Resistant ALD Coatings for Semiconductor Manufacturing Process Equipment

ALD coatings have been developed to protect process equipment against aggressive process conditions, specifically fluoride plasma. Here alumina and yttria based ALD coatings were deposited in a large-batch ALD reactor on silicon samples and mock-up showerheads. High conformality in 1:20 aspect ratio features was demonstrated. Plasma etch testing of the film revealed high resistance against the etch process for all the films in the Al2O3-Y2O3 system. Y2O3 mixing into the Al2O3 film was shown to rapidly increase the etch resistance of the film with diminishing effect as pure yttria was approached. Etch damage on the film was uniform showing no preference on grain boundaries or other features.