Popis: |
We report morphology of cylinder of diblock copolymers (BCP), which consist of polymer A and B, in cylindrical prepattern holes by dissipative particle dynamics simulation in order to predict optimal cylinder profile. Configuration of cylinder which consists of polymer B changes along with change of affinity of underlayer and guide wall for BCP. In the case of underlayer, neutral to both the polymer species shows the most stable cylinder shape. When affinity converts to either polymer, cylinder shape gets distorted. In the case of intergrading guide wall condition from A wet to B wet for a certain hole CD, polymer B, that constitutes cylinder, gradually loosen and stack on the guide eventually. Moreover cylinder forms again for B wet larger hole. Free energy for hole CD is also investigated and the profile shows A wet wall and B wet wall are suitable for hole shrink in a narrow and wide range of hole CD, respectively. Because free energy of A wet wall varies widely for hole CD change. In contrast, free energy of B wet wall exhibits no significant changes and the profiles signify that cylinder shapes relatively stable in wider range than A wet wall. |