Calculation and properties of thermal stress of monolayer film and solution of thermal stress of multilayer infrared antireflection coating by finite element analysis

The deposition of infrared antireflection coatings on silicon lenses is a widely practiced technique that has been extensively investigated by researchers over an extended period. Thermal stress is essential to the adhesion between the film and the substrate. To measure the magnitude of thermal stresses, we use the mechanical analysis method to convert thermal stresses into shearing and peeling stresses. Expressions for these two stresses are then derived. Then, we analyzed the effect of the monolayer film's properties on the silicon substrate's stress. The results indicate that peeling stress is the main factor affecting the adhesion between the film and the substrate, and various approaches can be employed to successfully mitigate the peeling stress exerted on the substrate. The influence of the multilayer film's structure on the peeling stress experienced by the silicon substrate was investigated through the utilization of finite element analysis. In this study, three distinct infrared antireflection coatings were deposited on silicon substrates individually. Subsequently, these coated substrates underwent rigorous environmental testing. The findings from this testing confirmed the accuracy of the stress analysis results obtained by finite element analysis for the multilayer film. Our research has resulted in solutions for determining the magnitude of shearing and peeling stress. We have employed finite element analysis to identify a suitable structure for an antireflection coating that exhibits minimal peeling stress. This advancement has the potential to improve the effectiveness of design processes and the adaptability of infrared antireflection coatings in various environmental conditions.