Getting to the bottom morphology of block copolymer thin films.

We demonstrate a general approach for attaining the bottom morphology of block copolymer (BCP) thin films. In our former measurements on PS- b-PMMA films, surface morphology maps of the BCP films revealed distinct ordering regimes where the cylinders orient predominantly perpendicular or parallel to the interface and an 'intermediate' regime where these morphologies coexist. However, this earlier work did not explore the bottom morphology of BCP thin films. In this study, we investigated the block copolymer morphology near the solid substrate in the cast block copolymer film having a perpendicular cylinder morphology on the surface. [ABSTRACT FROM AUTHOR]