This work investigates the shrinkage of microlens-imprints during the step-and-repeat mastering process in nanoimprint lithography (NIL). Lenses with 20 different shapes were fabricated using an EVG-S&R-NIL system to examine changes in lens shape and identify influencing parameters. The data obtained is used to enhance simulation tools, reducing the need for costly iterations of the master stamp. Profilometry and microscopy were used to evaluate lens profiles and the topological changes of the imprints. A Python script enabled direct assessment of the height differences of the lenses. Force measurements were used to investigate the variation of forces acting on the stamp during the step-andrepeat process as a function of changing process parameters. The results show dependencies on the thickness of the imprint layer and the lens shape, as well as on additional structures such as bonding plateaus. The data is intended to improve shrinkage prediction through simulations in the future and by that, to enable better control of lens changes by adjusting process parameters.
Analyzing Lens Shape Alterations in Nanoimprint Lithography for Wafer-Level Optics
Langbauer, L. M. (Author). 2025
Student thesis: Master's Thesis