Uniformity in Patterns Imprinted Using Photo-Curable Liquid Polymer

Imprint lithography is a candidate for high-resolution, high-throughput lithography using low-cost equipment. In particular, imprinting using photo-induced solidification is very attractive because it eliminates heat-up, cool-down time and avoids thermal expansion problems inherent in conventional thermal imprinting. We demonstrate the replication of uniform 100 nm line and space (L/S) patterns over a 5 mm × 5 mm area at a time, a 60 nm L/S pattern and a 90-nm-wide line with an aspect ratio of 2 by imprinting using photo-induced solidification. We studied the removal of a base layer by O 2 reactive ion etching (RIE) and determined the criteria for the base layer and imprinted patterns. Change in line width through O 2 RIE is not affected by the base layer thickness but is affected by etching time. We found that granules generated in polymer during O 2 RIE are slowly etched and the resulting long removal time of granules degrades the quality of imprinted patterns or prevents patterns from standing. It is necessary to achieve a base layer which is less than 100 nm thick or to change the O 2 RIE conditions so that the polymer dose not granulate and/or use granulation-resistant polymers.