Islands and holes on the free surface of thin diblock copolymer films. I. Characteristics of formation and growth

Abstract

When deposited on a silicon substrate, symmetric polystyrene/polymethylmethacrylate P(S-b-MMA) diblock copolymers form, at equilibrium, a multilayer structure parallel to the substrate. If the top layer is incomplete, islands or holes are formed in this layer. The kinetics of formation and growth of islands or holes is investigated, here, by in situ interference microscopy. The present study is focused on dense systems (≃ 30 % of islands (or holes) in area coverage). In the early stage, the way of formation of elevations and holes appears to be different. For longer times, the growth of islands and holes is controlled by the same mechanisms : individual growth, coalescence and dissolution