Imprint characteristics by photo-induced solidification of liquid polymer

Nanoimprint lithography is an attractive technology for LSIs era below 40-n m critical dimension from the viewpoints of high-throughput and low-cost eq uipment. In order to avoid a pattern placement error due to thermal expansi on in the conventional thermal imprint process, we attempted to replicate t he mold pattern onto a liquid polymer, which was solidified using ultra-vio let (UV) light irradiation at room temperature. The liquid polymer used her e was supplied by TEIJIN SEIKI Co., and termed TSR-820. It was spin coated on slide glass to produce approximately 1.5-mum-thick polymer film. The thi ckness remained after UV exposure and rinsing in acetone was observed at th e dose of 10 J/cm(2) and it saturated about a UV exposure dose of 100 J/cm( 2) with an increase in the exposure dose. The mold fabricated of quartz pla te was first pressed onto the polymer film at about 100 kg/cm(2) and then t he UV light was irradiated using an imprint apparatus developed for this wo rk. After releasing the mold from the film, the substrate was rinsed in ace tone to remove the residual liquid polymer. Eventually the minimum feature size of 100-nm line and 300-nm space pattern was successfully replicated in the polymer with good fidelity.