Nanoimprint lithography with a focused laser beam for the fabrication of micro-/nano-hybrid patterns†

A simple process which utilizes a 2D stamp based on UV-NIL is proposed. The main idea is to control the cured region on the micrometer scale by using a developable resist. For the conventional UV-NIL process, a collimated UV light is transmitted through the transparent stamp to cure the overall resist as shown in Fig. S1a. However, if the size of the UV light is reduced, the cured region of the resist can be also narrowed (Fig. S1b). After development, the uncured resist can then be removed and the remaining resist thus forms a coarse structure. On the top surface of the coarse structure, there are fine patterns generated by UV-NIL with the stamp. The width of the coarse structure can be determined by the size of the reduced UV light and the fine pattern on the coarse structure will be the inverted shape of the stamp pattern. A pinhole or a narrow slit can block the UV light for the aforementioned selective curing process. However, there are limitations to minimize the size of the coarse structure since the light is diffracted from the edge of the pinhole or slit and dispersed when it reaches the resist. If the selective curing process with UV blocking and the UV-NIL process are separated, it is possible to fabricate such hybrid patterns. 18,19 However, focusing of the UV light will be the proper way to reduce the size of the coarse structure independently of the effect of the transparent stamp in the proposed concept.