Pattern definition through guided self-assembly in thermal nanoimprint
We intend to apply guided self-assembly in thermal nanoimprint (T-NIL) for hierarchical pattern definition. To exploit the knowledge gained in a close-by field, capillary force lithography (CFL), comparable experiments are conducted and classified with respect to the surface profile obtained in the cavity, a key issue for controlled dewetting. Comparison of the results in literature for CFL with those obtained for T-NIL indicates unexpected differences between the two process types. Whereas CLF reports a transition from a W-shaped to a U-shaped meniscus with increasing polymer layer thickness, the opposite is the case for T-NIL. Similar differences exist in the theoretical description of the transition. With T-NIL it follows simple geometrical rules, nearly independent of temperature, whereas with CFL a temperature-dependent fitting of viscosity is applicable. We assign these differences to the different initial conditions. As a consequence, a simple transfer of CFL-rules to the control of guided self-assembly in T-NIL is not feasible.
guided self-assembly thermal nanoimprint lithography