Dewetting of thin UHV-deposited organic films

The dewetting of thin organic molecular films UHV-deposited on He-cooled substrate is analyzed by optical and AFM microscopies. By controlled annealing to room temperature such films can be transformed into patterns of isolated droplets. The description of the dewetting process takes advantage of the close similarity to pattern formation and dynamics in thin polymer films (polystyrene). Typical dewetting stages are discerned. Experimental results on films of a fulgide derivative, deposited on quartz glass substrates at thicknesses of 10 and 21.5 nm, are presented as example.