Optical, chemical and coverage properties of magnesium fluoride formed by atomic layer deposition

Magnesium fluoride (MgF 2 ) thin films deposited using atomic layer deposition (ALD) were studied for use as optical coatings, meta-surface anti-reflection layer, and chemically resistive passivation. The deposition was performed in a commercially available Picosun® R-200 Advanced ALD reactor. Characterization of composition, density, optical property, chemical resistivity and coverage were performed. ALD-deposited films showed high R + T at wavelength down to 350 nm, excellent 3D coverage, and high chemical resistivity. This technology enables unique properties to improve 3D structured optics such as metasurface.