Cross-sectional profile prediction from top-view SEM images based on root-cause decomposition of line edge roughness

摘要

Topographic profiles are reconstructed from top-view images in scanning electron microscope (SEM) by predicting a local slope angle based on how surface roughness (morphology) looks from top-view. Careful analysis of Line edge roughness (LER) reveals that LER obtained in top-view SEM images is decomposed into three components, parallel shift, cross-sectional shape deformation, and surface roughness, and the local slope angle of pattern surface is estimated from the surface roughness component, which corresponds to the projection of surface roughness onto the substrate plain. Cross-sectional profiles reconstructed by scanning this procedure across top-view SEM images showed good agreements with the results obtained by other metrology methods such as an atomic force microscope.