Investigating EUV radiation chemistry with first principle quantum chemistry calculations

In Extreme Ultraviolet (EUV) lithography, chemistry is driven by secondary electrons. A deeper understanding of these processes is vital to targeted engineering of materials. As electron interactions are non-discriminative, studying these processes directly in condensed phase with experiments is extremely challenging. Proxy experiments such as gas phase experiments and solution phase experiments are only viable to a limited subset of materials, limiting their use for large scale material screening. First principles quantum chemistry calculations have been adopted by various industries for materials development and investigation. We demonstrate that such calculations can be used to model processes involved in EUV radiation chemistry. We can reproduce experimental results and predict dose to clear with such calculations. In this article, we first demonstrate that primary electron energy spectrum can be predicted accurately. Secondly, the dynamics of a photoacid generator (PAG) upon excitation or electron attachment is studied with ab-initio molecular dynamics calculations. Thirdly, we demonstrate that electron attachment affinity is a good predictor of reduction potential and dose to clear.