Replication of HARMST and large area nanostructured parts using UV cationic polymerization

This paper reports on the development of a reaction casting process for the fabrication of high aspect ratio microstructures HARMST and large area nanostructured parts, using UV cationic polymerization. Besides the process itself, materials had to be characterized to achieve thick layers. An epoxide resin, a bis cycloaliphatic epoxide BCE and a divinylether of triethylene glycol DVE TEG were used as monomers and triaryl sulfonium salt TAS was used as the photoinitiator. The materials were characterized relative to their rheological properties, the degree of polymerization and their hardness. The test structure consists of columns with an aspect ratio of 10. The results reveal that the materials used show excellent behavior for the replication of high aspect ratio structures. The replication of a nanostructured area of 10 10 cm2 could also be realized with the presented process. The used structure is a 2D optical grating with a period of 2.5 amp; 956;m and a diameter of the tip of 300 n