Transfer Durability of Line-Patterned Replica Mold Made of High-Hardness UV-Curable Resin

Abstract

Ultraviolet nanoimprint lithography (UV-NIL) requires high durability of the mold for the mass production of nanostructures. To evaluate the durability of a line-patterned replica mold made of high-hardness UV curable resin, repetitive transfer and contact angle measurements of the replica mold were carried out. In the line patterns, as the contact angle decreases due to repeated transfer, capillary action occurs, and water flows along them. Therefore, it can be said that a mold with a line pattern exhibits an anisotropic contact angle because these values vary depending on the direction of the contact angle measurement. Subsequently, these anisotropic characteristics were investigated. It was determined that it was possible to predict the lifetime of line-and-space molds over repeated transfers. As the transcription was repeated, the contact angle along the line patterns decreased significantly before becoming constant. Moreover, the contact angle across the line pattern decreased slowly while maintaining a high contact angle with respect to the contact angle along the line pattern. The contact angle then decreased linearly from approximately 90°. The mold was found to be macroscopically defect when the values of the contact angle along the line pattern and the contact angle across the line pattern were close. Predicting the mold’s lifetime could potentially lead to a shortened durability evaluation time and the avoidance of pattern defects.

Transfer Durability of Re-release Coated Replica Mold on Ultraviolet Nanoimprint Lithography

“…As molds are used repeatedly, the durability of the release coating is of high significance [17][18][19]. In our previous study, a line and space (L&S) patterned mold was used to ensure the durability and lifetime of the release agent [20]. A brief explanation of this method is as follows.…”

Editorial for Special Issue: Nanoimprint Lithography Technology and Applications

“…One of the exciting things about nanoimprinting is the big versatility of the process and the broad range of applications it can be used for. This special issue includes 10 articles [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ] which represent a small glimpse of the challenges and possibilities of this technology.…”

“…Six contributions deal with nanoimprint processes aiming at specific applications [ 2 , 4 , 6 , 8 , 9 , 10 ], while the other four papers focus on more general aspects of nanoimprint processes [ 3 , 5 , 7 ] or present novel materials [ 1 , 3 ]. Several different types of nanoimprint processes are used: plate-to-plate [ 1 , 2 , 3 , 5 , 7 , 10 ], roll-to-plate [ 4 , 6 ], and roll-to-roll [ 8 ]. Plate-to-plate NIL here also includes the use of soft and flexible stamps.…”

“…Aspects of stamp fabrication are addressed in [ 3 ] by Marumo et al, including a way of stamp lifetime prediction.…”

“…In summary the application fields in this special issue can be identified as plasmonics [ 2 ], superhydrophibicity [ 4 ], biomimetics [ 4 , 9 , 10 ], optics/datacom [ 6 ], and life sciences [ 8 ]. The nanoimprint process related papers discuss filling and wetting aspects during nanoimprinting [ 3 , 5 , 7 ] as well as materials for stamps [ 3 ] and imprinting [ 1 ].…”