Room Temperature Dewetting of Polymer Thin Films Investigated by AFM and Low Voltage SEM

Abstract

Abstract Thin films (<100nm) of diblock copolymers are being investigated for various applications including templates for nanopatterning [1], electronic packaging materials, and biomedical applications. In such applications it is essential that stable defect free films be produced repeatedly. Because long and short range forces (like van der Waals) dominate thin polymer films, instabilities are introduced in the films when they are spin-coated onto hydrophobic substrates resulting in dewetting of the film from the substrate. Dewetting is initiated at a nucleation site in a metastable film leading to the formation of a dry patch and proceeds to grow by transport of material away from the nucleation site, forming a lip that surrounds the hole. Highly symmetrical structures form during progression of the dewetting process and completion of the process can be identified when all holes coalesce forming polygons outlined by droplets of the polymer film [2].