Interfacial Adhesion Studies for Step and Flash Imprint Lithography

摘要

The step and flash imprint lithography (SFIL) process requires the clean separation of a quartz template from a polymerimprint, and the force required to create this separation must be minimized to prevent the generation of defects.According to fracture mechanics principles, decreasing both the imprint polymer modulus and the interfacial fractureenergy are beneficial for reducing the separation force. Adjusting the crosslinker concentration in the imprintformulation decreases the modulus but does not significantly impact the facture energy. On the other hand, fluorinatedsurfactant additives to the imprint fluid lower the modulus of the imprint polymer and decrease the fracture energy. Thefracture energy is further decreased by using a nonreactive, liquid surfactant versus a surfactant that reacts with thepolymer matrix. Angle-resolved X-ray photoelectron spectroscopy (XPS) results indicate that surfactant migration ismore effective with a fluorinated surface treatment compared to an untreated quartz surface. This result shows that theuse of fluorinated surfactants must be accompanied by a surface treatment that produces a similar energy or polarity toinduce migration and lower the adhesive strength.