Analytical approach to metal oxide resist modeling: exposure, bake, and network formation

Metal oxide photoresists (MORs) have received attention for use in extreme ultraviolet (EUV) lithographic patterning, in which more established chemically amplified resists suffer from long blur lengths and low EUV absorptivity. To meet the demand for next-generation semiconductor devices, a thorough understanding of the physics behind MOR patterning is required to predict the outcome of arbitrary patterning schemes and to determine optimal process conditions. However, the ability to model and predict MORs through bake and development is still in early stages. We provide a modeling framework and associated analytical expressions that describe the behavior of MORs that have so far been described by kinetic Monte Carlo simulation approaches. We further extend the aforementioned analytical expressions to directly predict dose-to-gel transition energies for wet-developed MORs for arbitrary bake temperature and bake duration. Finally, we briefly compare our methodology using an in-house simulation program to patterning results from an experiment using Fractilia MetroLER™.