Removal Pathways of Out-of-Plane Defects in Thin Films of Lamellar Forming Block Copolymers

Abstract

Understanding the defect removal process is crucial for fabricating defect-free self-assembled structures in block copolymer thin films. Most previous studies mainly focused on the removal of in-plane dislocation and disclination defects, while out-of-plane defects receive less attention. In this study, the removal of two types of out-of-plane defects of lamellar forming block copolymer thin films, the tilted domain defect and the cross-sectional edge dislocation defect, are studied in detail using the string method coupled with the numerical self-consistent field theory (SCFT). It is found that the removal of the tilted domain defect can be regarded as an order–order transition process controlled by the nucleation and growth mechanism. On the other hand, the cross-sectional edge dislocation can be eliminated by either evaporating or growing its core (a partial domain). For both cases, multiple removal pathways have been identified by varying the height of the partial domains and the segregation strength ...