UV-based nanoimprint lithography: Toward direct patterning of functional polymers

This contribution sheds light on typical challenges in UV-based nanoimprint lithography (UV-NIL) from the perspective of direct polymer patterning. Direct polymer patterning is an emerging NIL technique with structure dimensions being much different from those in high resolution nanoimprint lithography resulting in new challenges and resist behavior being also much different from established NIL techniques. Special focus was put on very high structure aspect ratios, their filling behavior and structural shrinkage. Filling of large structures proceeded via squeezed flow rather than capillary filling. Top line width shrinkage was identified as remaining challenge for a faithful structure replication. Stamp-and-repeat UV-NIL with spin-coated films is discussed as an efficient process for manufacturing of planar photonics.