A scientific framework for establishing ultrafast molecular dynamic research in imec’s AttoLab

Abstract

Science stands on three legs: hypothesis, experiment, and simulation. This holds true for researching extreme ultraviolet (EUV) exposure of photoresist. Hypothesis: For resist exposure as patterns get smaller and closer together, approaching molecular units in width and resist-height, the molecular dynamics will limit the working resolution of the resist due to the formation of printing defects. Without taking proper consideration of these dynamics, the single-patterning lithography roadmap may end prematurely. Experimentally we are developing methods for sub-picosecond tracking of photoionization-induced processes. Using ultrashort pulses of light to excite and probe new materials with techniques that show the interactive dynamics of electronic and nuclear motion at the very limits of light-speed. This certainly holds true for exposing photoresists with EUV where ultrafast photoreactions induce chemical change via multiple pathways such as high-energy ionization fragmentation, recombination, and multispecies combination that ideally end in low-energy electron transfer reactions, analogous to lower energy photoreaction (but with a charge). In the nonideal case, these reaction processes lead to incompatible byproducts of the radiolysis that lead to types of stochastic defects. To do ultrafast studies we must build a foundation of knowledge using atomistic simulation to interpret transient molecular dynamic processes. Before we can do this, we need to learn how to simulate various spectral modalities to provide a starting point. In this work, we examine X-ray Photoelectron Spectroscopy of a model resist and use atomistic simulation to interpret the reactant-product composition of the spectral samples.