Effect of Oxygen Incorporation on the Properties of AlF₃ Films

In order to reveal the influence of oxidization on the properties of AlF3 films, single layers of AlF3 were deposited at different substrate temperature by thermo evaporation technique with or without oxygen injected into the coating chamber. The chemical composition, total stress, optical properties and laser damage resistance of samples were characterized. Comparative study indicates the AlF3 films prepared under higher oxygen pressure have more oxides which result from hydration process in atmosphere. The presence of oxides also reduces total stress and optical absorption of the fluoride coatings.