Improvement of the non-uniform resist patterns in the thermal nanoimprint process using Si stamp with nanoscale rod patterns.

To acquire the uniform resist patterns in thermal nanoimprint lithography (TH-NIL), the major considerations include control of the resist, stamp and substrate resist under the imprint condition. Examples of these factors are management of the imprinting pressure, imprinting temperature and releasing temperature. Non-uniform patterns of thermal imprinted resist appear after TH-NIL according to the pattern size, substrate size and resist thickness. Particularly, the hole-shaped patterns with a diameter of 100 nm and a height of 100 nm on a 4 inch Si wafer after TH-NIL were deformed under tension to the maximum strain 70%. The experimental results showed that uniform nano-patterns can be acquired by minimizing the thermal mismatch while nanoimprinting through using a pair of Si stamp and Si substrate, thinning the resist thickness and separating the stamp at a relatively high temperature.