Photo-nanoimprinting using SOFT (sample on flexible thruster) stage

In the photo-nanoimprinting, the base layer thickness decreases with imprint pressure and imprint time; however, the decreasing speed becomes very slow when the polymer thickness is below several hundred nm. The simple idea for resulting in thin base layer is supplying enough small amount of polymer (i.e., small droplet(s) or thin film). In the droplets system, a mold is soaked with the polymer by capillary action. The soaking action results air evacuation and the soaking time limits the process speed as presented in Chen et al. (2004). In the thin film system, no soaking time is required but it is quite difficult to bring a mold in full contact with the polymer so as not to catch air since the surfaces of the mold and the polymer are uneven. To solve the problem, we developed a novel sample stage, which equips wafer warp function, compatible to such a thin initial polymer thickness.