Interpretation of Line Edge Roughness in Extreme-Ultraviolet (EUV) Lithography using Molecular Simulations
발표자
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초록
내용
One of crucial challenges for achieving sub-1x nm patterning via extreme-ultraviolet (EUV) lithography is reducing the roughness at the edge of patterns while maintaining high resolution and sensitivity. Previous studies have focused on photochemistry and pointed out photon shot noise and acid diffusion as main reasons of line edge roughness (LER). However, as target size of patterns becomes smaller, desired LER is compatible to the molecular size of polymer chains and continuum approaches fail to capture physical phenomena associated with molecular conformations and their dynamics. We propose a new EUV photoresist simulation model which includes explicit description of polymer chains and its variation during EUV lithography process. With our new model effects of polymer chain conformation on LER are investigated under various process conditions.