A Fabrication Process for Nanopatterns Shrinkage with Variable Sizes for Large Area

Abstract

In this paper, a cost efficient process chain is designed to shrink periodic nanopatterns to tunable feature sizes. The feature size of the final patterns can be controlled and adjusted. 100 mm full wafers featuring square holes with 130 nm, 160 nm, 190 nm and 220 nm feature sizes are fabricated from the original wafer containing circular holes with a diameter of 350 nm. The fabrication chain involves well-known technologies such as etching and soft UV nanoimprint lithography (UV-NIL). Based on a single original master, an intermediate template is fabricated featuring an inversed pyramid pattern using soft UV-NIL and subsequent wet chemical etch. By utilizing the slope of the inversed pyramid structures, the mask on the final substrate can be opened featuring tunable dimensions. Cryogenic etching based on SF6/O2 chemistry enables the creation of the final shrunk nanopatterns with smooth and vertical profile. The fabrication cycles involve only short imprinting and etch processes coping without costly electron beam writings. Therefore, the original microand nanostructure wafer can be shrunk into nanopatterns with tunable feature sizes at a constant pitch in a cost effective manner. The generated periodic nanopatterns can be adopted to the fields of NIL templates, photonic crystals, optics, energy conversion and