Filling Behavior Observation of UV-curable Resin Using Bridge-Structure Mold

In recent years, owing to the increasing demand for semiconductors, decreasing the power consumption of semiconductor-exposure equipment has become an important issue. Therefore, ultraviolet nanoimprint lithography (UV-NIL), which can efficiently produce nanopatterns with reduced power consumption, is desirable. However, the problem with UV-NIL is that when the mold is subjected to a mold-release treatment, the water repellency increases, and the resin does not fill the interior of the fine pattern. Therefore, investigating the filling behavior is essential. Our previous study used hydrogen silsesquioxane (HSQ) as the bridge structure, which is a negative-type electron-beam (EB) resist with a film thickness of 300 nm. Using HSQ, the height of the bridge structure was less than 300 nm, and a small amount of UV-curable resin was obtained. Therefore, thicker negative-type EB resists are required to address this issue. In this study, a negative-type photoresist was used as the bridge structure via EB lithography. Consequently, the height and thickness of the bridge were approximately 6 and 2 µm, respectively, and hence, we could comprehensively pursue the filling behavior.