Molecular dynamics study on nanodust removal strategies from nanotrench structures

The process of removing nanodust adhering to nanostructured surfaces is important for improving yield and sustainability in manufacturing fields that utilize the structural characteristics of patterns. In this study, we computationally proposed a method to remove nanodust from a trench-shaped Si substrate using an atomic force microscopy tip. A molecular system is thus constructed in which a Si substrate with a trench structure, a cylindrical C tip, and a spherical Cu nanoparticle coexist. By moving the C tip in a specific direction and pushing it into direct contact with the Cu nanoparticle, the interaction force between the Cu and the sidewall of the Si substrate can be substantially reduced. In particular, moving the C tip in a direction parallel to the pattern can effectively push nanodust away while minimizing damage to the Si substrate. The damage experienced by the substrate during the process was comprehensively evaluated using the von Mises stress, adhesion energy, contact area, and strain energy density developed by the axial stress components. The suitability of this method was systematically evaluated based on the diameter of the Cu nanoparticle and its position relative to the C tip. For each case, the maximum strain energy experienced at the edge of the trench structure was quantified, which suggests appropriate nanoparticle removal process conditions from a structural perspective. The strategy can be potentially used as a repair method for semiconductor production components, such as pellicles and hard masks.