Controlled dewetting processes on microstructured surfaces - a new procedure for thin film microstructuring

We describe a new experimental attempt to generate defined ultrathin micros tructured polymer films. Microcontact printing of 11-undecanoic acid has be en used to modify the wetting properties of bare gold surfaces to prepare p oor wettable surface domains downward to 4 mu m size. Film formation of pol ystyrene films thinner than 20 nm was achieved by dip-coating from a soluti on of polystyrene in chloroform. The nucleation of holes and the dewetting process was completely controlled by the I heterogenity of the surface. Lar ge areas with well defined during the dip-coating process. The remaining fi lm hole patterns were achieved by the controlled dewetting showed no indica tions for dewetting on the bare gold surface. Especially at higher polymer concentrations Rayleigh instabilities within coalescent rims or adjacent ho les are shown to influence the film morphology. Some criteria which are rel evant for the design of surface film patterns. by controlled dewetting are discussed. Low voltage scanning electron microscopy (LVSEM) which is used appears to b e an excellent method for the characterisation of ultrathin films and organ ic layers downward to 5 nm thickness.