EUV stochastic pattern anomalies are a major obstacle in future EUV lithography, and they depend on processes such as development, underlayers, extrinsic anomalies, and resist materials. This paper explores the impact of molecular clustering on EUV stochasticity using the discrete dev/etch model since the above factors can impact stochasticity through mechanical interactions among nearby molecules. Pattern formations with larger/denser molecular sub-clusters (SCs) suppress stochastic pattern anomalies because forming such sub-clusters requires more photons. Stochastic pattern anomalies increase with thinning resist films, however, since the dispersion in the sub-cluster ratio within a small volume of exposed resist film increases as the volume size approaches the cluster size. LWRs and defect probabilities in thin resist films decrease with increasing the sub-cluster density requirements. Underlayers (ULs) and extrinsic anomalies in resist materials influence stochasticity through their interactions with molecular SCs. Interfacial defects are highly dependent on conditions of UL surface and sub-cluster formation. Extrinsic defects and resist fluctuations with a scale longer than the SC size generate defect floors or magnify stochastic defect probabilities, while those shorter than the SC size have little impact. Controlling sub-cluster requirements may help keep LWR and defect probability sufficiently low, but this generally is at the expense of resist sensitivity.
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