UV Nanoimprint Lithography Using an Elementwise Embossed Stamp

Ultraviolet-nanoimprint lithography (UV-NIL) is a promising method for cost-effectively defining nanoscale structures at room temperature and low pressure. In an attempt to apply a large area stamp to UV-NIL in a low vacuum environment, we have proposed a new UV-NIL process using an element-wise embossed stamp (EES), which consists of a number of elements, each of which is separated by channels. Nano-scale patterns of each element were fabricated using e-beam lithography and an etching process in which a Cr film was employed as a hard mask for transferring nanostructures to a quartz plate. Before pressing the EES, low viscosity resin droplets with a nano-liter volume were dispensed on each element of the EES. Experiments on UV-NIL were performed on an EVG620-NIL. 380 nm - 1 µm features of the EES were successfully transferred to 4 in. wafers. We measured patterns and residual layers on the imprinted wafers to evaluate the potential of the proposed process. Experiments showed that the EES enables UV-NIL using a large-area stamp in a low vacuum environment.