A complete system of nano-imprint lithography for IC production

The imprinting method most suited to semiconductor IC applications in the sub-50 nm realm is the step and flash technique 1,2 currently under development at the University of Texas. In this technique, the space between a rigid fused-silica mold, that has a low-aspect-ratio pattern etched into its surface, and a silicon wafer is filled with a low viscosity photopolymer precursor. After the polymer is cured by exposure to ultraviolet radiation, the mold is removed and the pattern in the polymer layer is transferred into the silicon wafer by reactive ion etching. Before this lithographic technique can be employed in VLSI production, a method to ensure accurate overlay between the mold and wafer patterns must be devised, feature CD control must be maintained under adverse conditions and a low cost way of fabricating, inspecting and repairing a mold must be developed. To accomplish these tasks we propose using: a) an adaptive mold holder and b) a new type of binary mold.