Laser heat-mode patterning with improved aspect-ratio

Abstract Heat-mode lithography has received much attention owing to its capacity of breaking through the diffraction limit and realizing nano-patterning. However, the relatively lower aspect ratio of patterns seriously limits its scope of applications. In the currently available literature, the aspect ratio of submicron structures prepared by this method is less than 0.3:1. In this work, a new two-step development process was proposed to considerably improve the aspect-ratio of micro/nanostructures in the AgInSbTe (AIST) heat-mode resist. An aspect ratio of 1:1 can be kept even for the grating structures with a linewidth/period of 200nm/400 nm. The developed patterns can be transferred to silicon substrates with high fidelity. This simple and effective technique addresses key issues of heat-mode lithography in the manufacture of functional nanostructures requiring high aspect ratio, such as photomasks, templets of nanoimprint, and so on.