Silicon oxynitride based scratch resistant anti-reflective coatings

Scratch resistant anti-reflective (SRAR) coatings were developed on Gorilla Glass substrates. A reactive magnetron sputtering process was employed to enable desired layer hardness and refractive index. Optical modeling was performed to determine the effective hardness of the SRAR coatings, in an effort to reduce reflectance in the visible while maintaining high scratch resistance. Scratch resistance was evaluated by using a nano-indentation test. Broadband AR coatings were realized. Potential applications of the SRAR coatings for AD optics were discussed.