Antireflection coating for sapphire with consideration of mechanical properties

A theoretical model based on the model of elasticity is used to simulate the stress field of several simplified single- and multilayer coatings under indentation load. Based on these results the stresses relevant for the failure of the coating are identified. The influence of different coating parameters like thickness, material choice and layer arrangement is examined. The results of this analysis are considered when designing an antireflective coating with optimized mechanical resilience. A modified coating is deposited and the scratch resistance is compared to an established coating. As indicated by the simulation the optimized coating shows an enhanced scratch resistance.