Collapse of patterns with various geometries during drying in photolithography: numerical study

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Photolithography is one of the main mass nanoproduction processes. Manufacturing small devices by photolithography is a challenge because of the risk of collapse of patterns during the drying of rinse liquid. Literature models are usable for only long (i.e., LAR, pattern length/spacing greater than 20) two-line parallel patterns. In the current study, a numerical framework is introduced that allows study the collapse of different pattern geometries. In this framework, the rinse interface shape is found using Surface Evolver, and pattern deformation is found using ANSYS through coupled modeling. The results of the new numerical approach, was in agreement with the analytical model results in the range of its applicability (i.e., long two-line parallel pattern). The developed numerical framework was then used to study a few simple geometries where the analytical model was not applicable. One of the findings from the numerical framework results was that, despite the fact that buttresses stiffen the patterns, buttressed patterns deform more owing to the increase in Laplace pressure.