Ordered pattern formation from dewetting of polymer thin film with surface disturbance by capillary force lithography

摘要

The dewetting process of thin polystyrene (PS) film with built-in ordered disturbance by capillary force lithography (CFL) has been investigated in situ by AFM. Two different phenomena are observed depending on the excess surface energy (ΔF_γ) of the system. When ΔF_γ is less than a certain critical value (i.e., the disturbance amplitude is under a critical value), the PS film would be flattened and become stable finally by heating above T_g. While, if the size of the disturbance amplitude is larger than the critical value, ordered PS liquid droplets form by further dewetting. The pattern formation mechanisms and influencing factors have been discussed in detail.