Improvement of imprinted pattern uniformity using sapphire mold

Imprint lithography is an attractive technology for LSIs era below 40-nm critical dimension from the viewpoints of high-throughput and low-cost equipment. In order to avoid a pattern placement error due to thermal expansion in the conventional thermal imprint process, we have previously attempted to replicate a mold pattern onto a liquid polymer, which was solidified using ultra-violet (UV) light irradiation at room temperature. The imprint technology based on photo-induced solidification has several advantages such as elimination of heat-up and cool-down time and possibility of step and repeat process. However part of the solidified polymer film was remained on the quartz mold surface. In order to improve this problem, in this article we propose to use a sapphire plate as a mold.